chondrichthyans from a cenomanian (late cretaceous) bonebed, saskatchewan, canada: canadian...

CHONDRICHTHYANS FROM A CENOMANIAN (LATE

CRETACEOUS) BONEBED, SASKATCHEWAN,

CANADA

by CHARLIE J. UNDERWOOD* and STEPHEN L. CUMBAA�*School of Earth Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK; e-mail [email protected]

�Earth Sciences, Canadian Museum of Nature, PO Box 3443 Stn ‘D’, Ottawa, ON K1P 6P4, Canada; e-mail [email protected]

Typescript received 20 August 2009; accepted in revised form 11 November 2009

Abstract: Acid preparation of samples of a bonebed from

the Cenomanian of central Canada yielded several thousand

well-preserved chondrichthyan teeth, in addition to numer-

ous other vertebrate remains. Teeth and other remains of

one species of chimaeroid, one species of hybodont shark,

three species of Ptychodus, 10 species of neoselachian sharks

and two species of batoid were recorded. The family Archae-

olamnidae fam. nov., genera Meristodonoides gen. nov. and

Telodontaspis gen. nov. and species Ptychodus rhombodus sp.

nov., Telodontaspis agassizensis gen et sp. nov., Eostriatolamia

paucicorrugata sp. nov., Roulletia canadensis sp. nov., Creto-

rectolobus robustus sp. nov. and Orectoloboides angulatus sp.

nov. are described. Status of the genus Palaeoanacorax and

the species Cretoxyrhina denticulata, Squalicorax curvatus and

‘Rhinobatos’ incertus are discussed, and reconstructed denti-

tions of Archaeolamna and Roulletia presented. The fauna is

of low diversity and dominated by active hunters, with many

species apparently endemic to the northern Western Interior

Seaway.

Key words: Canada, Cretaceous, hybodonts, lamniforms,

Ptychodus, ray, shark.

T he Western Interior Seaway was a broad and relatively

shallow body of water that, through the ‘mid’ and Late

Cretaceous, stretched across the North American conti-

nent from the Boreal Ocean in the North to the Tethys

Ocean in the south. Rocks deposited within the seaway

are well known for their fossil vertebrates, with chondri-

chthyans, teleosts, reptiles and birds all being well repre-

sented (e.g. Russell 1988, 1993). Despite these rich faunas,

study has been very uneven, and the sharks and rays have

received relatively little attention. In addition, it has been

recognized that there were strong biogeographical con-

trols on vertebrate distribution (Nicholls and Russell

1990), resulting in very different assemblages occurring in

rocks for the southern and northern parts of the seaway.

Chondrichthyan faunas from the Cenomanian are rela-

tively well known from Texas (e.g. Welton and Farish

1993; Cappetta and Case 1999), but far less so from the

mid and northern parts of the seaway. Abundant shark

teeth, mainly lamniforms, have been recorded from a

number of sites across the central and northern parts of

the USA (e.g. Cicimurri 2001a, b; Shimada et al. 2006),

but poor illustrations and conservative taxonomy have

sometimes rendered these difficult to interpret. Recorded

faunas from further north have typically been from shal-

low water to marginal facies (Case 2001, Cook et al.

2008). Cenomanian vertebrate faunas from more offshore

sites typically occur in bone-rich sandstones (e.g.

Cicimurri 2001a) or limestones (e.g. Cicimurri 2001b;

Shimada et al. 2006), presumably representing hiatal

horizons. Similar sandstones, limestones and mudstones

are also present in western Manitoba (McNeil and Cald-

well 1981, pers. obs.), whereas true bonebeds, usually with

a carbonate cement, occur in otherwise generally noncal-

careous-laminated mudstones in eastern Saskatchewan

(e.g. Cumbaa and Tokaryk 1999; Schroder-Adams et al.

1999, 2001). These bonebeds (Cumbaa and Tokaryk 1999;

Cumbaa et al. 2006) contain a very rich fauna dominated

by pelagic predatory vertebrates, in particular lamniform

sharks, enchodontid teleosts and hesperornithiform birds.

GEOLOGICAL SETTING

The Upper Cretaceous succession of the Western Interior

Seaway across North America has yielded Cenomanian

sharks from a number of sites throughout the region (as

summarized by Cook et al. 2008). The Cretaceous rocks

in central Canada rest unconformably on Palaeozoic and

Precambrian basement rocks and are dominated by mud-

stones, with coarser clastic material and carbonates both

[Palaeontology, Vol. 53, Part 4, 2010, pp. 903–944]

ª The Palaeontological Association doi: 10.1111/j.1475-4983.2010.00969.x 903

being very limited. On the eastern edge, this succession

forms the Manitoba Escarpment, a broken line of hills

and uplands running from south-western Manitoba and

terminating in the Pasquia Hills of eastern Saskatchewan.

The foot of the escarpment is largely obscured beneath

sediments deposited along the margins of glacial Lake

Agassiz. Exposures are limited, but a number of man-

made excavations and natural river cliffs are present.

Sandstones and siltstones of Albian age are overlain by a

series of mudstone formations ranging in age from Ceno-

manian to Late Campanian. These mudstones are typi-

cally laminated, and benthic organisms are very limited in

diversity, with only oysters and inoceramids being abun-

dant. Although vertebrate fossils are present throughout

the Upper Cretaceous succession, bone concentrations

and bonebeds are only known from the Belle Fourche

Member of the Ashville Formation. This unit is Cenoma-

nian in age, with the Cenomanian ⁄ Turonian boundary

being present within the lower part of the overlying Keld

member of the Favel Formation (see Cumbaa et al. 2006).

Although concentrations of vertebrate material have been

recorded at a number of localities in eastern Saskatche-

wan and western Manitoba, the bonebed from the expo-

sures on the Bainbridge River in the Pasquia Hills (e.g.

Cumbaa et al. 2006) has so far yielded the most abundant

vertebrate material (see Text-fig. 1). Material from other

sites is currently under study.

The main exposure on the Bainbridge River is a river

cliff known as Royal Saskatchewan Museum locality num-

ber 63E09-0003. Owing to the protected nature of the site,

full coordinates of the site are kept with the specimens at

the Royal Saskatchewan Museum. The majority of the cliff

comprises rocks of the Favel Formation (see Schroder-

Adams et al. 1999, fig. 7), with the Belle Fourche Member

largely obscured below scree. Small exposures do, however,

allow the stratigraphy to be recorded, and about 5 m of

carbonate-free laminated mudstones are seen. Within the

middle part of this are numerous discontinuous, thin beds

and starved ripples of very fine sandstone, many rich in fish

scales. Although the bonebed occurs within this interval, it

is rarely seen at outcrop. Poor exposures and fallen mate-

rial show that it comprises a level of very discontinuous

lenses within the Ostrea beloiti beds, a stratigraphic unit

associated with a widespread marker bentonite, believed to

be a northern continuation of the ‘X’ bentonite in the wes-

tern interior of the United States (Cumbaa and Bryant

TEXT -F IG . 1 . Map of the Manitoba

Escarpment, modified from Cumbaa

et al. (2006). The sections of Late

Cretaceous escarpment are: 1, Pasquia

Hills; 2, Porcupine Hills; 3, Duck

Mountain; 4, Riding Mountain; and 5,

Pembina Mountain. The sample site in

the Pasquia Hills region is marked with

a star.

904 P A L A E O N T O L O G Y , V O L U M E 5 3

2001; McNeil and Caldwell 1981). The only lenses found in

situ were just over 2 m below this marker bentonite (Cum-

baa and Bryant 2001). Bonebed lenses are up to 0.2 m thick

and often have a strongly scoured base and irregularly rip-

pled top. Large mudclasts of bentonite are common within

the lenses and sorting of clasts is strongly evident. The

bonebed is clast supported, with little or no matrix between

the clasts of bones, teeth, coprolites and phosphate

nodules, which are held together by calcite cement. Most

bioclasts in the bonebed are extremely well preserved. All

of the neoselachian teeth have their root preserved (with

the exception of those that appear to have been partly

digested, and there is very little abrasion). The general

lack of roots on hybodont teeth may be the result of

resorption. Many fragile bird long bones are complete, and

a large proportion of broken bones have longitudinal

breaks, suggesting early breakage prior to loss of organic

material. A small proportion of larger bones are highly

abraded, but this is almost unknown amongst smaller

specimens.

The Bainbridge River bonebed is sedimentologically

similar to one described from the Carrot River, 100 km

to the south-west (see Cumbaa et al. 2006), which has a

similar fauna but which is much more restricted (Phillips

2008). Both of these bonebeds lie within the ‘middle’ to

Late Cenomanian benthic foraminiferal Verneuilinoides

perplexus Zone (McNeil and Caldwell 1981), but radio-

metric age determinations have yet to be made on the

Bainbridge locality. The Carrot River bonebed is capped

by a bentonite dated by 40Ar ⁄ 39Ar at 95.17 Ma (Cumbaa

et al. 2006). Faunal and sedimentological characteristics

of the bioclastic units present elsewhere along the escarp-

ment have not yet been investigated, although they are

thought to be roughly synchronous.

MATERIAL AND METHODS

Samples of the Bainbridge River bonebed were collected

as loose blocks in the stream bed and banks. As clear size

sorting could be seen, the coarser-grained blocks were

preferentially collected, as these could be seen to contain

more large shark teeth and tetrapod bones. Some blocks

were weathered, and vertebrate fossils could be collected

from degraded heaps of bone material in the field, but

the majority were very well lithified and were collected

for later acid digestion.

Bonebed samples were broken down in buffered 5–10%

acetic acid, with the undissolved residue removed every

few days and washed and dried. Samples were sieved and

sorted down to 1-mm mesh size. For this study, about

20 kg of bonebed was dissolved and studied, with a fur-

ther large collection of specimens used for comparative

purposes. A single block of about 5 kg total weight

yielded 4432 identifiable shark teeth in the >1-mm mesh

size fraction.

Despite the large number of shark teeth within the

coarse and medium (>1 mm) sieve fractions, there were

very few identifiable remains of chondrichthyans in the

fine sieve fraction. Not only do the <1-mm sieve fractions

contain large quantities of fragmented teleost material,

making sorting for chondrichthyan material very time

consuming, but shark and ray teeth are genuinely very

rare in these fractions compared to the coarser material.

For these reasons, it was not practical to sort more than a

representative sample of the fine material, resulting in an

underrepresentation of the small-toothed taxa.

Larger specimens were ammonium chloride coated

before photography and greater focal depth was obtained

by digitally blending images of different focal distances.

Very small teeth were imaged by SEM, and therefore, have

a somewhat different appearance to optically photo-

graphed material and are presented on separate plates.

Dentitions were reconstructed by comparison with extant

taxa, but variations in the relative shapes of parasymphyse-

al and intermediate teeth and second and third upper ante-

rior teeth between extant taxa make the relative positions

of these teeth in the fossil reconstructions provisional.

Specimens were collected under Saskatchewan Heritage

Palaeontological Resource Investigation Permit # 06-03P,

and are deposited in the collections of the Royal Sas-

katchewan Museum, Regina, Saskatchewan, prefix RSM.

SYSTEMATIC PALAEONTOLOGY

Remarks. Descriptive tooth terminology largely follows

that of Cappetta (1987).

Class CHONDRICHTHYES Huxley, 1880

Subclass SUBTERBRANCHIALIA Zangerl, 1979

Order CHIMAERIFORMES (Berg, 1940) sensu Patterson, 1965

Family EDAPHODONTIDAE Owen, 1846

Genus EDAPHODON Buckland, 1838

Edaphodon sp.

Plate 1, figures 1–2

Material. One fragmentary palatine plate (P2989.43). Several

other indeterminate chimaeroid plate fragments may also be

referable to this taxon.

Description. The identifiable fragment is from the distal part of

the left palatine plate. In occlusal view, the anterior inner tritor

occupies over a third of the width of the plate and its entire

length, with neither end being preserved. The outer part of the

occlusal surface is concave and smooth, with the distal end of

U N D E R W O O D A N D C U M B A A : C A N A D I A N C R E T A C E O U S C H O N D R I C H T H Y A N S 905

the outer tritor being just visible at the posterior end of the

specimen. The symphyseal edge is smooth and short. The outer

part of the basal face of the plate is smoothly convex, becoming

flat or concave in the inner part. There is a well-developed

descending lamina which extends for half of the width of the

plate and is made up of tissue comprising packed longitudinal

tubes.

Remarks. There is no evidence to suggest that the frag-

ments of chimaeroid present here belong to more than

one species, although additional taxa may be present.

The overall morphology of the plates and the form of

the tritors suggests an edaphodontid affinity, and com-

parisons with better preserved coeval material by Evgeny

Popov suggested that they belonged to Edaphodon. All

of the remains seen belong to small tooth plates, proba-

bly not exceeding 50 mm long, contrasting to far larger

sizes reached by tooth plates of many of the species of

Edaphodon.

Subclass ELASMOBRANCHII Bonaparte, 1838

Cohort EUSELACHII Hay, 1902

Order HYBODONTIFORMES Maisey, 1989

Superfamily HYBODONTOIDEA Owen, 1846 sensu Zangerl,

1981

Family HYBODONTIDAE Owen, 1846

Subfamily HYBODONTINAE Owen, 1846

Genus MERISTODONOIDES gen. nov.

Derivation of name. From the general resemblance to the teeth

assigned to Meristodon by Agassiz (based on indeterminate mate-

rial), which has commonly been used for the genus named here.

Type species. Hybodus rajkovichi Case, 2001 from the Cenoma-

nian, Late Cretaceous of MN, USA.

Included species. It is considered here that several species can be

included into Meristodonoides gen. nov. These are as follows:

Hybodus butleri Thurmond, 1971 from the Aptian or Albian of

Texas; Hybodus montanensis Case, 1978 from the Campanian of

Montana and Wyoming; and Hybodus novojerseyensis Case and

Cappetta, 2004 from the Early Maastrichtian of New Jersey. A

number of other taxa described on fragmentary material are

probably also referrable to this genus.

Diagnosis. Hybodont shark known largely from teeth, but

partial fin spines and cephalic spines from sediments

where this genus occurs may be congeneric. There is a

low degree of heterodonty, which is mainly represented

by changes in the relative size of main cusp and lateral

cusplets and strength of ornamentation. Separated from

other genera by the following combination of characters:

(1) tooth close to symmetrical with single, well-developed

cusp being erect or slightly inclined lingually with only

slight distal inclination in lateral teeth; (2) main cusp

round to slightly labiolingually flattened in cross-section

with continuous but very weak cutting edge; (3) lateral

cusplets absent, incipient or very small relative to main

cusp and well separated from it; where they are present

there is a degree of heterodonty, presumably dignathic;

(4) ornament of longitudinal striae never coalescing to

form labial boss except very weakly in posterior teeth of

some species; (5) root very low and somewhat expanded

lingually, excavated on basal surface (6) root very strongly

vascularized, with row of many small foramina below

base of crown on labial face, but vascularization on the

basal face of root extremely variable. Fin spines probably

tuberculate, lacking strong longitudinal ridges.

Remarks. Teeth of this genus are separated from Hybodus

s.s. Agassiz, 1837 (H. reticulatus Agassiz, 1837 and similar

forms) by the presence of a single well-developed cusp,

very low root and, for some species, lack of a labial boss.

Teeth of Egertonodus Maisey, 1987 have multiple, well-

developed cusps but are in other respects similar. Teeth

of Planohybodus Rees and Underwood, 2008 have a simi-

lar overall shape but differ in being far more compressed,

having a far better developed cutting edge and having a

root with a basal face that is more strongly excavated

labially. Teeth of all other Jurassic and Cretaceous

hybodont genera have morphologies very different from

Meristodonoides gen. nov.

The subgenus Meristodon Agassiz, 1837 was erected for

a collection of isolated tooth crowns from the British

Early Cretaceous. The figures suggest that these are inde-

terminate, but are likely to be a mixture of teeth of Eger-

tonodus and Planohybodus. Despite this, the genus

Meristodon has been used to refer to teeth from the Late

Cretaceous (e.g. Glickman 1980; Underwood and Ward

EXPLANATION OF PLATE 1

Figs 1–2. Edaphodon sp.; ·5.5; P2989.43, partial palatine plate, 1, occlusal view. 2, basal view.

Figs 3–18. Meristodonoides rajkovichi (Case, 2001); all ·6.5. 3–5, P2989.44, posterolateral tooth. 3, labial view. 4, lingual view. 5, basal

view. 6–8, P2989.45, lower anterior tooth. 6, labial view. 7, basal view. 8, lingual view. 9–11, P2989.46, upper posterolateral tooth.

9, labial view. 10, lingual view. 11, basal view. 12–13, P2989.47, upper anterior tooth. 12, labial view. 13, lingual view. 14–15,

P2989.48, upper lateral tooth. 14, labial view. 15, lingual view. 16, P2989.49, lower anterior tooth, labial view. 17–18, P2989.50,

lower lateral tooth. 17, labial view. 18, lingual view.


PLATE 1

UNDERWOOD and CUMBAA, Edaphodon and Meristodonoides

1 2

3

6

5

4

7

8

9

10

11

12

16

18

15

17

14

11

13

2008), as the heterogeneous nature of the type material

had not been recognized.

The known range of Meristodonoides gen. nov. is from

Aptian or Albian (Thurmond 1971) to Early (e.g. Case and

Cappetta 2004) or possibly Late (Case 1979, as Hybodus

sp.) Maastrichtian. Most records of Meristodonoides gen.

nov. have been from within the Western Interior Seaway,

but it is also known from Kazakhstan (D. Ward, pers.

comm. 2008) and northern Europe (Biddle 1993, as Hybo-

dus sp.; Underwood and Ward 2008, as Meristodon sp.).

Meristodonoides rajkovichi (Case, 2001)


?1993 Hybodus sp. Williamson et al., p. 449, fig. 3.1.

1999 Hybodus sp. 1. Cappetta and Case, p. 53, figs 1–2.

1999 Hybodus sp. Cumbaa and Tokaryk, p. 61, fig. 5

(pars, 8 teeth in left 2 columns).

2001 Hybodus rajkovichi Case, pl. 1, fig. 5, pl. 2, figs 1–2.

?2001b Hybodus sp. Cicimurri, p. 185, fig. 5a.

2006 Hybodus sp. Cumbaa et al., p. 146, fig. 4.1.

?2008 Hybodus sp. Cook et al., p. 1189, fig. 4A.

Material. About 2000 teeth studied including P2989.43–

P2989.50. Only 20 of the teeth studied have a root preserved.

Description. Teeth show weak monognathic and dignathic het-

erodonty. The crowns of teeth of this species are typically about

as wide as high, reaching about 8 mm. The tooth is relatively

symmetrical, with the main cusp in the centre of the crown. The

main cusp is 1.5–2 times as high as broad at the base and is the

only well-developed cusp on the majority of teeth. There are one

or two pairs of low to incipient lateral cusplets; where more

strongly developed the teeth are presumed to be (by analogy

with other hybodonts) from upper anterior positions. The main

cusp curves gently lingually and in some teeth has a very gentle

inclination towards the posterior. The labial face of the cusp is

gently convex, separated from a more strongly convex lingual

face by a small but continuous cutting edge. Labial ornament is

restricted to the lower quarter to half of the main cusp, where it

is represented by 6–12 longitudinal ridges, which become stron-

ger towards the base. In the lateral parts of the crown, these

ridges are similar or may be stronger and frequently reach the

apex of the cusplets or occlusal cutting edge. Ornament on the

lingual face is similar but finer, with the ridges sometimes reach-

ing nearly to the apex of the main cusp. The ornament reaches

the crown-root junction on the labial side and close to it on the

lingual face. The root is preserved in less than one per cent of

the teeth. The root is deeper (labiolingually) higher and wider

than the crown. The labial face of the root is very low, and flares

somewhat towards the base, where there is a large recess in the

basal face of the root on the labial side. A row of many very

small foramina are present just below the labial crown-root

junction. The root lingual face comprises a narrow and lingually

sloping shelf and a vertical face. In addition to a row of many

very small foramina just below the labial crown-root junction,

larger and more irregularly spaced foramina are present across

the root face. The basal root face is flat with a hollowed-out

recess. Very small foramina are present across the root basal

face, the number and size being very variable between individual

teeth. Larger and often rather elongate foramina are restricted to

the labial side of the root within the recess. Fragments of fin

spines tentatively referred to this taxon have an ornament of

regularly spaced, oval, tubercles.

Remarks. Many of the teeth of this species compare well

with type material but a greater degree of heterodonty

may be seen than previously recognized. Many of the

teeth described here have a finer and longer ornament of

fine ridges than the figured type assemblage (Case 2001),

but intermediate morphologies are present showing this

to be intraspecific variation. The presence of a proportion

of teeth with clearly developed lateral cusplets, but in all

other respects identical to the type material, suggests that

a greater degree of dignathic heterodonty is present

within this genus than previously recognized. This species

is very similar to Meristodonoides butleri (Thurmond

1971), but teeth have a higher and more slender cusp and

appear to have a weaker labial ornament and finer lingual

ornament (although it is hard to be sure from the draw-

ings of the type material).

The vast majority of well-preserved, isolated, post-

Triassic hybodont teeth lack a root, whereas teeth in

associated dentitions from the same deposits typically

have well-preserved roots (CJU, pers. obs.). This suggests

that the loss of the root is not commonly a result of


Figs 1–17. Ptychodus rhombodus sp. nov. Figs 1–10 · 4.75; Figs 11–17 · 9. 1–2, P2989.51, holotype, anteriolateral tooth. 1, occlusal

view. 2, lateral view. 3–4, P2989.52 lower symphyseal tooth. 3, occlusal view. 4, lateral view. 5–6, P2989.53? lower anterior tooth.

5, occlusal view. 6, lateral view. 7–8, P2989.54 lateral tooth. 7, occlusal view. 8, lateral view. 9–10, P2989.55 posterolateral tooth.

9, occlusal view. 10, lateral view. 11, P2989.56 posterolateral tooth, occlusal view. 12–13, P2989.57 posterolateral tooth. 12,

occlusal view. 13, lingual view. 14, P2989.58 posterolateral tooth, occlusal view. 15, P2989.59 upper symphyseal tooth, occlusal

view. 16–17, P2989.60 posterolateral tooth. 16, occlusal view. 17, lingual view.

Figs 18–21 Ptychodus sp.; all ·4.75. 18–19, P2989.62, lower symphyseal tooth. 18, occlusal view. 19, lateral view. 20–21, P2989.63

posterolateral tooth. 20, occlusal view. 21, lingual view.


PLATE 2

UNDERWOOD and CUMBAA, Ptychodus rhombodus

1

35

2

4

6

1211

9

7

810

16

1415 17

13

20

2119

18

taphonomic processes but was because of resorption of

the root-crown contact during tooth dehiscence.

Order INCERTAE SEDIS

Family PTYCHODONTIDAE Jaekel, 1898

Genus PTYCHODUS Agassiz, 1838

Type species. Ptychodus mammillaris Agassiz, 1839 from the Late

Cretaceous of Europe.

Ptychodus rhombodus sp. nov.

Plate 2, figures 1–17; Plate 8, figure 1

1999 Ptychodus sp. Cumbaa and Tokaryk, p. 61, fig. 5

(pars, 4 teeth in third column).

2006 Ptychodus anonymus Williston 1900; Cumbaa et al.,

p. 146, fig. 4.3.

Derivation of name. From strongly rhombic shape of most teeth.

Holotype. P2989.51 (Pl. 2, figs 1–2).

Additional material. One hundred and fifty-six teeth studied

including P2989.52–P2989.61.

Diagnosis. Teeth small and low. Strong heterodonty, sym-

physeal teeth quite square in occlusal view, all other teeth

asymmetrical and rhombic to some degree. Dentition with

many more files of small, rhombic, compressed lateral teeth

than larger and more square anterior teeth. Crown low and

outer part of crown flat, with small but conspicuous raised

‘cusp’ towards centre of anterior teeth, inclined to posterior

in lateral teeth. Ornament continues across all of occlusal

face with no clearly defined marginal area. Ornament of

four to 15 subparallel ridges (typically 6–10 in lateral teeth,

8–14 in anterior teeth), rarely bifurcating other than close

to edge, breaking up to tubercles at edges and often towards

labial margin of larger teeth. Root low and strongly lin-

gually inclined. Foramina below root-crown junction on all

sides, especially conspicuous on labial root face.

Description. Teeth are small for the genus, with the largest being

13 mm wide, and the majority less than 10 mm. They demon-

strate a high degree of heterodonty although very few symphy-

seal teeth are present. All teeth are wider than deep, although

this is only slightly so in symphyseal teeth; many of the smaller

lateral teeth are approximately twice as wide as deep. In occlusal

view, all but symphyseal teeth are strongly rhombohedral in

shape, with the lingual edge of the tooth displaced posteriorly.

The crown on all teeth is low, with the occlusal face being gently

convex but with a low but distinct swollen ‘cusp’ on all but the

smallest posterior teeth. In lateral teeth, this is on the posterior

side of the tooth. The sides of the crown are smoothly concave

on lateral and labial faces but there is a well-developed concave

notch on the lingual face. The ornament on the occlusal face is

rather variable but intermediate forms are present. The domi-

nant ornament are subparallel ridges running from the anterior

to posterior side of the crown. In anterior and anterolateral

teeth, there are between 10 and 15 ridges, with fewer present in

posterolateral teeth, with as few as four ridges in the most pos-

terior teeth. There are occasional examples of ridges bifurcating,

largely restricted to close to the lateral and labial margins of the

teeth. Towards the lingual edge of many teeth, the ridges

become more curved with the concave side towards the labial

face. The ridges reach close to the anterior and posterior edges

of the crown, breaking up into small tubercles at the crown

edge, especially in larger teeth. There is commonly an area of

broken ridges or tubercles towards the labial crown edge. There

is no marginal area to the crown, and ornament continues

unbroken to the crown edge. The crown overhangs the root on

all sides. The root is of similar height and narrower than the

crown. The root is strongly inclined lingually in all but symphy-

seal teeth, and in some lateral teeth the lingual margin of the

root extends out beyond the lingual margin of the crown. The

lateral faces of the root are all flat, and all have small foramina

just below the root-crown junction, although these are especially

well developed on the labial face. The basal face of the root is

flat and has small and irregularly spaced foramina, sometimes

with the addition of one or two larger foramina.

Remarks. These teeth are highly variable in overall shape

but intermediate morphologies demonstrate that they

clearly belong to a single taxon. The large proportion of

highly compressed, small and asymmetrical lateral teeth

has not been previously noted with any Ptychodus species;

articulated dentitions of Ptychodus decurrens Agassiz, 1838

(see Woodward 1912) do have several files of compressed

lateral teeth, but also possess several files of nearly sym-

metrical anterior teeth, whilst dentitions of other Ptycho-

dus species have proportionally far fewer reduced lateral

teeth. This species shares a lot of characteristics with

Ptychodus decurrens Agassiz, 1838 and P. anonymus Will-

iston, 1900, but can clearly be separated from these.

Teeth of P. decurrens share an almost identical occlusal

ornament to P. rhombodus sp. nov., but differ in having a

crown that has a far more evenly domed profile, lacking the

flat surface with central small cusp seen here, and a larger

maximum size. It is also probable that the dental formula

was different. Teeth of P. anonymus are also similar, but

differ in having a more clearly defined granular margin sur-

rounding the ridged occlusal ornament, and a higher and

more clearly defined cusp. Ptychodus janewayii Cope, 1874

was erected on some small and strongly rhombic teeth from

the Cenomanian of Kansas, which are considered here to

probably represent more than one species. Although it is

possible that at least one of the type series is conspecific

with the material described here (Williston 1900, fig. 9), the


two specimens mentioned in the diagnosis (therefore

including, by inference, the holotype) have only four and

five folds, respectively, far less than recorded on any similar

sized tooth of P. rhombodus sp. nov. As the low lateral and

posterior teeth of this taxon are not clearly differentiated

from those of P. anonymus, it is possible that P. rhombodus

sp. nov. has not been recognized in assemblages where its

remains are rare. It is likely that P. rhombodus sp. nov. and

P. anonymus are closely related, and it is possible that the

probable Middle Cenomanian P. rhombodus sp. nov. is

ancestral to the Late Cenomanian to Coniacian (Shimada

et al. 2006) P. anonymus.

Ptychodus sp.


Material. One lower symphyseal tooth and one posterolateral

tooth (P2989.62 and P2989.63).

Description. The larger tooth is 12 mm wide and has a total

height of 10 mm, the smaller tooth is 5 mm wide. The crown of

the symphyseal tooth is roughly rectangular in occlusal view,

being somewhat expanded on the labial edge and having a

prominent indentation on the lingual edge. The majority of the

crown is taken up by a roughly conical cusp, which is somewhat

wider than high. This is surrounded by a narrow but distinct flat

marginal area on the lateral edges but is absent on the labial

edge. The posterolateral tooth is rather rhombic in profile, with

the posterior edge being ‘stretched out’. A prominent domed

cusp occupies the central region of the crown. The crown of

both teeth is ornamented by about 10 subparallel ridges, which

pass over the cusp, some bifurcating on the cusp flanks. In both

teeth, ornament fades out to a smooth outer edge of the crown,

although there has been some wear or abrasion of the lateral

parts of the larger tooth. The labial side of the crown of the lar-

ger tooth is ornamented by small but distinct granulation, which

is also present on the small area of vertical cusp face on the lin-

gual side. The crown of both teeth is flared basally and over-

hangs the root on all sides. The root is shallow, especially so in

the posterolateral tooth, and slightly displaced lingually. Foram-

ina of various sizes are present just below the crown-root junc-

tion on all sides but are especially prominent on the lingual face.

The basal face of the root is slightly concave and has several,

irregularly spaced, foramina of different sizes.

Discussion. Teeth are similar to those of both P. rhombo-

dus sp. nov. and P. anonymus, but appear to differ from

both. The symphyseal tooth is larger than any compara-

tive tooth of P. rhombodus sp. nov., and both teeth have

a far more conspicuous cusp and a more clearly defined

marginal area. It is, however, possible that these represent

atypical teeth of a large individual of P. rhombodus sp.

nov. The general shape and ornamentation are very

similar to that of P. anonymus but differ in the lack of a

well-defined granular marginal area.

Ptychodus ex. gr. decurrens Agassiz, 1838


1839 Ptychodus decurrens Agassiz, p. 154, pl. 25b, figs 1–2,

4, 6–8.

1993 Ptychodus decurrens Agassiz, 1838; Welton and

Farish p. 59, figs 1–7.

1999 Ptychodus decurrens Agassiz, 1838; Cappetta and

Case p. 55, pl. 2, fig. 9.

?1999 Ptychodus decurrens Agassiz, 1838; Cappetta and

Case p. 55, pl. 2, figs 7–8.

2001a Ptychodus decurrens Agassiz, 1838; Cicimurri, p. 41,

fig. 6C–D.

2006 Ptychodus decurrens Agassiz, 1838; Shimada et al.

p. 7, fig. 6.3–6.4.

2006 Ptychodus decurrens Agassiz, 1838; Cumbaa et al.,

p. 146, fig. 4.5–4.6.

Material. Three teeth (P2989.64–P2989.66).

Description. The largest of the teeth referred to this species is

from an anterior position and has a maximum dimension of

12 mm, whilst the other, lateral and symphyseal, teeth are some-

what smaller. Both lateral teeth are somewhat asymmetrical and

rhombic in occlusal view, the anterior one having similar width

to depth, the other being slightly wider than deep. These lateral

teeth have a crown that is gently and evenly domed, without a

marginal area, with ornament continuing to the crown margins.

The symphyseal tooth is rather ‘arrowhead-shaped’ in occlusal

view, with a wide and concave lingual margin. The crown is

weakly domed, and the ornament does not reach the crown

margins. The crown ornament of the largest tooth comprises

about 10 well-developed ridges, which grade from smoothly

curved near the crown lingual edge to being folded back on

themselves near the labial edge. There is some bifurcation of the

ridges, and some breaking up of the ridges close to the crown

margins, but generally the ornament continues to the crown

edge. The ornament of the other teeth comprises numerous sub-

parallel, fine, ridges cover the lingual two-thirds of the crown,

with the lingual part being ornamented with irregularly broken

ridges and fine granulations. The crown of the largest tooth is

somewhat thicker than that of the others, but all have a similar

degree of overhang over the root. The edges of the crown are

convex on the labial and lateral edges, but concave on the lin-

gual side, especially so in the symphyseal tooth. The root is rela-

tively low and displaced to the lingual edge. Foramina are

present both close to the crown-root junction and on the root

basal face, with numerous small foramina and scattered larger

ones being present in both places.

Discussion. These teeth agree well with previous descrip-

tions of the species. The teeth considered to belong to

this species have rather different ornament, but all share a

similar tooth shape and fall within the morphological

range of teeth of P. decurrens. Although several subspecies

of P. decurrens have been named (e.g. Herman 1977), it

has been shown that ornament is very variable amongst


teeth from the same stratigraphical interval, and even

within the same articulated dentitions (e.g. Woodward

1912). The two teeth with the finer ornament are P. de-

currens var. oweni of Woodward 1912. Despite this varia-

tion, it is possible that more than one species or form

exists, as teeth from the Turonian ⁄ Coniacian boundary

(Cappetta and Case 1999) appear to have fewer and

stronger ridges on the crown than teeth figured from the

Albian to Turonian.

Subcohort NEOSELACHII Compagno, 1977

Order LAMNIFORMES Berg, 1958

Family CRETOXYRHINIDAE Glickman, 1958

Genus CRETOXYRHINA Glickman, 1958

Type species. Oxyrhina mantelli Agassiz, 1843 from the Late

Cretaceous of England.

Remarks. Teeth of Cretoxyrhina mantelli have been

recorded as extremely widespread in rocks of Albian to

Campanian age (for full synonymy and records of occur-

rence see Herman 1977; Siverson 1992, 1996; Siverson

and Lindgren 2005). Throughout the temporal range of

the species, distinct changes in tooth morphology occur,

with specimens from older rocks generally being smaller,

more gracile and having lateral cusplets in many tooth

positions, contrasting with the larger, more robust teeth

typically lacking lateral cusplets present in specimens

from younger rocks (e.g. Siverson 1996; Siverson and

Lindgren 2005). Cretoxyrhina denticulata (Glickman,

1957) was erected for Cenomanian material within which

lateral cusplets are present in posterolateral teeth. The

diagnosis of C. denticulata was vague, and it has been

unclear whether these are a temporal morph of C. man-

telli or represent a recognizably different species. Siverson

(1996) appears to suggest that the two are synonymous

but does not include the type material of C. denticulata

in the synonymy of C. mantelli. Reexamination of some

of the syntype specimens of C. mantelli (CJU, pers. obs.)

suggests that C. denticulata represents a species that can

be readily separated from C. mantelli.

Cretoxyrhina denticulata (Glickman, 1957)


1912 Oxyrhina mantelli Agassiz; Woodward, plate XLIII,

figs 11–13.

1957 Isurus denticulatus Glickman, p. 105, figs 1–4,

6–17.

?1993 Cretoxyrhina mantelli (Agassiz); Welton and Farish

p. 101, figs 1–12, p. 102, figs 1–2.

?1996 Cretoxyrhina mantelli (Agassiz); Siverson, p. 821,

figs 1–18.

2000 Pseudisurus denticulatus (Glickman); Zhelezko,

plate II, figs 1–5.

?2001a Cretoxyrhina mantelli (Agassiz); Cicimurri, p. 42,

fig. 7.i–k.

?2001b Cretoxyrhina mantelli (Agassiz); Cicimurri, p. 185,

fig. 5j.

2006 Cretoxyrhina mantelli (Agassiz); Cumbaa et al.,

p. 146, fig. 4.13.

2006 Cretoxyrhina mantelli (Agassiz); Shimada et al.,

p. 15, fig. 10.9–10.10.

2008 ?Cretoxyrhina cf. C. mantelli (Agassiz); Cook et al.,

p. 1192, fig. 5A.

Material. Nineteen teeth studied including P2989.67–P2989.74.

Description. The teeth of this taxon appear to largely represent

juveniles, with only three teeth of larger, presumed adult, indi-

viduals. The largest tooth, probably from the fourth lower file,

is 30 mm in greatest dimension. The teeth show a high degree

of monognathic and dignathic heterodonty (see Shimada 1997;

Siverson 1996; Siverson and Lindgren 2005 for details), as well

as ontogenetic heterodonty; the largest tooth here lacks lateral

cusplets which are present in smaller teeth from similar jaw

positions. Anterior teeth have a cusp that is higher than the

tooth width and is about twice as high as wide. The cusp is

rather labiolingually compressed and straight but inclined to

the posterior. The cusp lingual face is almost flat, whilst the

labial face it smoothly convex. The edges of the cusp flare out-

wards at the base, and in all but a large adult tooth, have a

pair of incipient to very low lateral cusplets. The crown is un-

ornamented other than some faint wrinkles near the base of

the crown on the lingual face of some teeth. The base of the

crown is straight to faintly arched, and does not overhang the

root. The root comprises well-developed root lobes forming an

internal angle of about 90–100 degrees. The anterior root lobe


Figs 1–6. Ptychodus ex. gr. decurrens Agassiz, 1838; all ·4.5. 1–2, P2989.64, upper symphyseal tooth. 1, occlusal view. 2, lateral view.

3–4, P2989.65, anterior tooth. 3, occlusal view. 4, lateral view. 5–6, P2989.66, lateral tooth. 5, occlusal view. 6, lateral view.

Figs 7–22. Cretoxyrhina denticulata (Glickman, 1957); Figs 9–14 · 2.25; Figs 15–22 · 4.5. 7–8, P2989.67, anterior tooth of subadult. 7,

lingual view. 8, labial view. 9–10, P2989.68, ? fourth lower tooth of adult. 9, labial view. 10, lingual view. 11–12, P2989.69,

posterolateral tooth of adult. 11, labial view. 12, lingual view. 13–14, P2989.70, lower lateral tooth of subadult. 13, labial view. 14,

lingual view. 15–16, P2989.71, parasymphyseal tooth of adult. 15, lingual view. 16, labial view. 17–18, P2989.72, ? upper lateral

tooth of juvenile. 17, labial view. 18, lingual view. 19–20, P2989.73, posterolateral tooth. 19, labial view. 20, lingual view. 21–22,

P2989.74, ? third upper tooth of neonate. 21, labial view. 22, lingual view.


PLATE 3

UNDERWOOD and CUMBAA, Ptychodus and Cretoxyrhina

2

1

34

109

65

7 8

13

14

15

1622

2019

17

11 12

18

21

is longer than the posterior in all teeth seen. The root lobes

are relatively parallel sided and have a smoothly rounded to

slightly pointed termination. The root is labiolingually com-

pressed with a very wide and flat linguo-basal face. There is a

narrow shelf at the base of the crown on the lingual side but

no well-developed protuberance. There is a small foramen at

the top of the root linguo-basal face, with other foramina being

very small and largely confined to a row below the labial

crown-root junction. Lateral teeth have a similar overall design

to those of more anterior positions, but are wider and lower.

The cusp is strongly inclined to the posterior and may be

slightly curved in some teeth. This is flanked by a pair of small

but conspicuous lateral cusplets, which are roughly triangular

in shape. The root lobes are widely separated and the basal

angle is very obtuse.

Discussion. The larger specimens recorded here are simi-

lar to those figured by Welton and Farish (1993), which

are all large teeth presumably of adults. Teeth of

C. mantelli are recorded from younger rocks (e.g. Shi-

mada 1997; Siverson 1996; Siverson and Lindgren 2005)

and differ in having a greater maximum size, and have

wider cusps and less well-developed cusplets throughout

ontogeny, which are largely absent within adults. This

material suggests that teeth from almost all jaw positions

of juveniles of C. denticulata had lateral cusplets, which

are retained in lateral and posterior teeth of adults.

Some specimens from the Late Cenomanian only possess

lateral cusplets on posterolateral teeth (e.g. Welton and

Farish 1993; Siverson 1996) and are only tentatively

referred to this species. Although often uncommon,

C. denticulata has been recorded in many Cenomanian

sites where open marine facies have yielded extensive

chondrichthyan faunas. It is, therefore, likely to have

been a globally distributed generalist tolerant of a wide

range of local conditions.

Family OTODONTIDAE Glickman, 1964

Genus CRETALAMNA Glickman, 1958

Type species. Otodus appendiculatus Agassiz, 1843 from the

Turonian of England.

Remarks. The genus Cretalamna was suggested by Siver-

son (1999) to belong within the Otodontidae Glickman,

1964, and the dental formula (Shimada 2007) would seem

to support this interpretation. There has been discussion

about the spelling of Cretalamna (Cappetta 2006), but it

is here considered that the predominance of usage in

recent years and relative timing of change in ICZN rules

and reassessment of the spelling suggest that the spelling

used here is correct.

Cretalamna sp.


?1993 Cretolamna woodwardi Herman; Welton and Farish,

p. 105, figs 1–3.

2006 Cretolamna appendiculata (Agassiz); Cumbaa et al.,

p. 146, fig. 4.12.

2006 Cretalamna appendiculata (Agassiz); Shimada et al.,

p. 15, fig. 10.5–10.8.

Material. One tooth (P2989.75).

Description. The single tooth is an upper lateral tooth with a

slightly imperfectly developed root. The tooth is slightly wider

than high with a slightly distally inclined main cusp being over

half the total tooth width. The main cusp is higher than wide

and has a gently convex anterior edge and concave posterior

edge. This is flanked by a pair of triangular lateral cusplets, each

about twice as wide as high. All of the cusps are labiolingually

compressed, with a very slightly convex lingual face and moder-

ately convex labial face. There is a strong and continuous cutting

edge across all cusps. There is no ornament on any of the

crown, the base of which is only slightly arched, so that the

cusps are all in a row. Enameloid does not extend down over

the root on either side. The root is strongly labiolingually com-

pressed, and root lobes are not clearly differentiated, with just a

gentle indentation in the central part of the basal edge of the

root. Both labial and linguo-basal faces of the root are flat.

Discussion. The single tooth recovered in this study, in

addition to rare teeth recorded from the Carrot River

(Cumbaa et al. 2006) appear to belong to a single species

that is conspecific with material figured by Welton and

Farish (1993) as Cretolamna woodwardi. These teeth differ


Figs 1–2. Cretalamna sp.; ·2.25; P2989.75, upper lateral tooth, 1, labial view. 2, lingual view.

Figs 3–23. Eostriatolamia paucicorrugata sp. nov; all ·6.5. 3–5, P2989.76, holotype, upper lateral tooth. 3, anterior view. 4, labial view.

5, lingual view. 6–8, P2989.77, ? first lower lateral tooth. 6, labial view. 7, lingual view. 8, anterior view. 9, P2989.78, upper lateral

tooth, labial view. 10, P2989.79, lower lateral tooth, labial view. 11, P2989.80, ? third upper anterior tooth, labial view. 12–13,

P2989.81, upper posterolateral tooth. 12, labial view. 13, lingual view. 14–16, P2989.82, ? first upper anterior tooth. 14, labial

view. 15, lingual view. 16, posterior view. 17, P2989.83, ? third lower anterior tooth, labial view. 18–19, P2989.84, ? lower

parasymphyseal tooth. 18, labial view. 19, lingual view. 20, P2989.85, ? second lower anterior tooth, labial view. 21–23, P2989.86,

? second upper anterior tooth. 21, labial view. 22, anterior view. 23, lingual view.


PLATE 4

UNDERWOOD and CUMBAA, Cretalamna and Eostriatolamia

1 2

4

3

5

6 7 8

9

12

11

13

14

15

16

10

17 19

18

20 2123

22

markedly from the type material of Dwardius woodwardi,

with smaller lateral cusplets in anterior teeth and greater

labiolingual compression and a straighter root in lateral

teeth. The overall tooth design is far closer to that of Cre-

talamna appendiculata but differs in possessing a more

robust root with a far more rounded profile. The tooth

described here is also considerably larger then in coeval

C. appendiculata. It is here considered that the species

C. appendiculata, as typically used, is in reality a number

of distinct and readily definable species, of which this is

but one.

Family ODONTASPIDIDAE Muller and Henle, 1839 s.l.

Remarks. Although the extant species Carcharias taurus

Rafinesque, 1810, Odontaspis ferox (Risso, 1810) and

Odontaspis noronhai (Maul, 1955) are all included into the

Odontaspididae by Compagno (2001), there is evidence

that the ‘family’ is polyphyletic and should be split into

two or even three separate families. The taxa within the

Odontaspididae have very different dentitions, and these

different dental formulae are readily recognized in the

fossil record. In addition, molecular phylogenetic work

(Human et al. 2006) suggests that O. ferox belongs in a

clade with Pseudocarcharias Cadenat, 1963 and Alopias

Rafinesque, 1810, whereas C. taurus is in a clade with the

Lamnidae Muller and Henle, 1838. Although defining new

families containing extant taxa is beyond the scope of this

paper and would involve considerable anatomical study of

modern specimens, it is considered here that the Odonta-

spididae should not be considered as a natural grouping.

Family ODONTASPIDIDAE Muller and Henle, 1839 s.l.,

?Odontaspis ferox group

Genus EOSTRIATOLAMIA Glickman, 1980

Type species. Lamna venusta Leriche, 1929 from the Campanian

of France.

Remarks. The genus Eostriatolamia was erected for Lamna

venusta and a number of other Carcharias-like taxa from

the Cretaceous, including Odontaspis striatula Dalinkevi-

cius, 1935. The genus was considered to be a junior syno-

nym of Carcharias by Cappetta (1987), who stated that

the teeth of L. venusta and O. striatula were similar. It is

here considered that L. venusta and O. striatula are con-

generic, but do not belong to Carcharias.

Teeth of E. striatula very closely resemble those of Ce-

nocarcharias tenuiplicatus Cappetta and Case, 1975, the

similarities being recognized by Welton and Farish

(1993). Cappetta and Case (1999) suggested that C. tenui-

plicatus differs from E. striatula in being smaller, thicker,

having a less inclined cusp and having stronger lingual

ornament. Despite this, figured specimens of both species

show great heterodonty and variation in ornament, with

no specimens representing the same probable tooth posi-

tion being figured from both species. It is here considered

that Cenocarcharias should be considered a junior syno-

nym of Eostriatolamia, with E. tenuiplicatus and E. striatu-

la being very closely related or possibly conspecific.

Eostriatolamia paucicorrugata sp. nov.


?2001b Cenocarcharias tenuiplicatus (Cappetta and Case);

Cicimurri, p. 185, fig. 5r.

2006 Cenocarcharias tenuiplicatus (Cappetta and Case);

Cumbaa et al., p. 148, fig. 5.2.

Derivation of name. From weak corrugations on the labial face

of the crown.


Additional material. One hundred and fifty teeth studied includ-

ing P2989.77–P2989.86.

Diagnosis. Heterodonty well developed and probably of

Odontaspis ferox type. Teeth small and gracile, typically less

than 10 mm high. Root and base of crown quite symmet-

rical in all teeth, with main cusp distally inclined or curved

in presumed upper lateral files. Main cusp higher than

wide in all teeth, widening towards the base, especially in

lateral teeth. Lingual curvature of cusp present in anterior

teeth. One or two pairs of short but robust lateral cusplets

present in all teeth, clearly separated from main cusp but

joined by broad labial base of crown. Cusplets sharply

pointed and higher than wide in anterior teeth but similar

width and height in lateral teeth. Lateral edge of outer cus-

plets overhangs outer edges of root, weakly in anterior

teeth, strongly in lateral teeth. Base of crown extends at

least half way down labial face of root lobes and does not

strongly overhang the root in lateral teeth. A continuous

and well-developed cutting edge extends over all cusps.

Crown ornament restricted to faint and irregular corruga-

tions at base of labial face and, in some teeth, very faint

longitudinal striations on lingual face of cusps. The root is

strongly bilobed with a very prominent nutritive groove in

all teeth. Root lobes form basal angle of 70–140 degrees.

Linguobasal face of root slightly arched and flattened.

Description. Teeth of this species are relatively small, with the

largest anterior teeth being 11 mm high. There is considerable

heterodonty that appears to follow the same pattern as in Odon-

taspis ferox.


All anterior teeth and most lower lateral teeth are nearly sym-

metrical, whilst the main cusp of upper lateral and some lower

posterolateral teeth are inclined to the posterior, even though

the base is still centrally situated on the tooth. Anterior teeth

have a straight and slender main cusp flanked by a pair of small

but clearly differentiated lateral cusplets; a second pair of very

small lateral cusplets is present on some teeth. The main cusp is

triangular in profile, with smoothly tapering sides, and is consid-

erably more than twice as high as wide. The main cusps of lower

anterior teeth are very slightly curved lingually but this curvature

is not seen in upper teeth. Lateral cusplets of anterior teeth are

longer than wide and are slightly divergent. The cusps are united

by a well-developed lower part of the crown, which extends for

at least half of the length of the root lobes on the labial side.

This basal part of the crown is rather swollen and overhangs the

root labially. At the crown-root junction on the lingual face, a

well-developed, recessed, neck is present around the base of the

main cusp. There is typically an indentation on the labial face of

the crown between the basal edge and the base of the lateral cus-

plets. The labial face of all cusps is gently convex, although this

may be flat or slightly concave at the base of the main cusp.

This face is separated from the strongly convex lingual face by a

small but continuous cutting edge. Ornament is weak on both

sides of anterior teeth. Ornamentation of the labial face is pres-

ent in most, but not all, teeth as irregular and short wrinkles at

the base of the cusps, usually concentrated in the area between

the main and lateral cusps. On the lingual face ornament is also

weak or absent, comprising numerous extremely fine longitudi-

nal ridges on the lower third of the main cusp. Roots of all ante-

rior teeth are strongly ‘V’ shaped, with the angles between the

root lobes varying from 70 to 110 degrees, largely depending on

jaw position. The root lobes gently taper towards somewhat

pointed terminations, and the main difference between anterior

and posterior root lobes is the degree of angularity of the lobe

termination. The labial face of the root is narrow and at least

partly overhung by the crown. The lingual side of the root has a

well-developed lingual protuberance in all teeth but this is espe-

cially well developed in lower anterior teeth where it is very pro-

nounced. A deep and very well-developed nutritive groove is

always present. Lingual faces of the root lobes are somewhat

concave and there is a marked, but not sharp, angle between the

labial and lingual faces. Lower parasymphyseal teeth are not

much smaller than other anterior teeth and similar in overall

form to other lower anterior teeth but are considerably more

compressed anterior distally. A single very small, fragmentary,

tooth is probably from an upper parasymphyseal position.

Lateral teeth are wider and lower than anterior teeth, in many

jaw positions being approximately as wide as high. In all teeth,

the base of the main cusp comprises about a third of the tooth

width, being flanked by a single, or more commonly double,

pair of lateral cusplets. In profile, the main cusp of all teeth is

somewhat concave towards the base, and the base merges with

the inner pair of cusplets. The main cusp is erect in lower teeth

but posteriorly inclined in upper teeth and does not show lin-

gual curvature in any tooth position. Lateral cusplets are higher

than wide when two pairs are present but similar width and

height on teeth possessing only one pair. The outer edge of the

cusplets overhangs the root lobes, giving a somewhat ‘spearhead’

profile. All cusps are united to a well-developed labial extension

of the crown, which extends at least half way down the labial

face of the root and forms a distinct overhang at its base in the

centre, but not on the root lobes. The lateral parts of the crown

on the labial side of the tooth are swollen, and there is typically

a concavity at the base of the lateral cusplets, especially in upper

teeth. The labial face of all cusps is weakly convex, and there is a

strong and continuous cutting edge separating crown lingual

and labial faces. Strong and irregular vertical corrugations are

usually present on the labial face of the crown but do not extend

onto the cusps. On some teeth from both lower and upper posi-

tions, these are restricted to a single ridge below the lateral cus-

plets or absent altogether. The lingual face of the crown is

convex and sometimes ornamented with very fine longitudinal

striations on the lower part of the main cusp. A well-developed

but narrow neck is present along the lingual crown-root junc-

tion. Both anterior and posterior root lobes are similar and have

an angle between the root lobes of between 115 and 140 degrees.

The root of upper teeth is more compressed labiolingually than

of lower teeth, and root lobes are somewhat wider but otherwise

they are similar. Root lobes are slightly longer than the lateral

extent of the crown, with the labial face of the root being partly

covered by the crown. The remainder of the root labial face is

shallow and somewhat flared towards the base. On the lingual

side of the tooth, there is a narrow but prominent shelf below

the base of the cusps. This shelf is separated from the linguo-

basal face of the root by a clear and relatively sharp edge. The

linguo-basal face of the root is quite flat and somewhat concave.

Below the base of the main cusp, the root extends lingually,

weakly in upper teeth but more strongly in lower teeth, and a

very prominent nutritive groove is present. A tooth of presumed

third upper anterior ⁄ first intermediate position has a morphol-

ogy intermediate between that of anterior and lateral teeth but is

more inclined to the posterior than either and, if it is from an

adult, somewhat smaller.

Remarks. Teeth of Eostriatolamia paucicorrugata sp. nov.

are similar to specimens referred to Eostriatolamia striatu-

la and E. tenuiplicatus, and probably represent a closely

related species. Although some specimens of E. striatula

lack ornament on the labial or both crown faces (speci-

mens of which Dalinkevicius (1935) only tentatively

referred to the species), an ornament of short and strong

ridges is usually present at the base of the labial face, and

fine striations are typically present on the lingual face of

the main cusp of teeth referred to E. striatula and E. ten-

uiplicatus. In contrast, ornament is very restricted on

teeth of E. paucicorrugata sp. nov. In addition, lateral cus-

plets are more robust in E. paucicorrugata sp. nov. than

in other, related, species, and there is a greater tendency

for a second pair of lateral cusplets to be present, whilst

the base of the labial crown face extends further along the

root lobes and does not overhang the root to the same

degree. Teeth of E. paucicorrugata sp. nov. also resemble

those of E. subulata (Agassiz, 1843), but teeth of E. subu-

lata differ in possessing larger lateral cusplets and a


straight labial crown base, which does not extend onto

the root lobes. E. paucicorrugata sp. nov. teeth differ from

those of ‘Odontaspis’ saskatchewanensis Case et al. 1990

(which is probably conspecific with Carcharias sp. A. of

Welton and Farish 1993 but that very small number of

specimens recorded for ‘O.’ saskatchewanensis prevents

detailed comparison) by its larger size, wider lateral cus-

plets and flared labial base of the crown.

Although general tooth morphology of Eostriatolamia

paucicorrugata sp. nov. is very similar to that of Carcha-

rias taurus, the lack of the numerous files of reduced pos-

terior teeth present in C. taurus confirm generic

separation (Glickman and Averianov 1998). Despite the

lack of sufficient material to reconstruct the dentition of

E. paucicorrugata sp. nov., it is tentatively suggested that

the dental formula would resemble that of Odontaspis fe-

rox. This is suggested by a moderate-sized tooth resem-

bling that of the third upper anterior ⁄ first intermediate

position of O. ferox, whilst two different sizes of parasym-

physeal teeth have been recognized in E. striatula by Da-

linkevicius (1935) and are probably also present in this

species.

Eostriatolamia paucicorrugata sp. nov. appears to be a

species endemic to the northern part of the Western

Interior Seaway, being known only from Canada and

possibly North Dakota and Wyoming (Cicimurri 2001b).

Further south it is absent but replaced by E. tenuiplica-

tus, which is present in Texas (Cappetta and Case 1975,

1999; Welton and Farish 1993) and Colorado (Shimada

et al. 2006). The limited ranges of these species contrasts

with the widespread distribution of E. striatula (e.g.

Dalinkevicius 1935; Landemaine 1991; Biddle 1993;

Siverson 1997).

Family ODONTASPIDIDAE Muller and Henle, 1839 s.l.,

Carcharias taurus group

Genus ROULLETIA Vullo et al., 2007

Type species. Roulletia bureaui Vullo et al., 2007 from the Ceno-

manian of France.

Roulletia canadensis sp. nov.

Plate 5, figures 1–24; Text-figure 2A–D

1999 Carcharias sp. Cumbaa and Tokaryk, p. 61, fig. 5

(pars; bottom tooth centre right column).

2006 Carcharias amonensis (Cappetta and Case); Cumbaa

et al., p. 148, fig. 5.1.

2006 Dallasiella willistoni Cappetta and Case; Cumbaa

et al., p. 148, fig. 5.3.

2006 Carcharias amonensis (Cappetta and Case); Shimada

et al., p. 12, fig. 9.1–9.2.

Derivation of name. From abundant specimens being apparently

restricted to Canada.

Holotype. P2989.107 (Pl. 5, figs 15–16), third lower lateral tooth.

Additional material. About 4500 teeth studied including

P2989.87–P2989.106; P2989.108–P2989.111.

Diagnosis. Dentition of Carcharias type with three differ-

entiated upper and three lower anterior teeth, upper inter-

mediate teeth and lower parasymphyseal teeth. All but

first upper and lower teeth somewhat asymmetrical. Orna-

ment lacking on all teeth. Crown rather flared on labial

face, overhanging top of root. Cutting edge continuous

across main and lateral cusps in all teeth. Anterior teeth

with steadily tapering, triangular main cusp and very small

to incipient lateral cusplets not reaching base of main

cusp. Root of all teeth with clearly defined lobes and well-

developed nutritive groove. Root of anterior and first lat-

eral teeth strongly ‘V’ shaped. Root lobes roughly parallel

sided with rounded terminations and only slightly flat-

tened basal face. Lateral teeth all have main cusp inclined

to posterior, in teeth posterior of second lateral position

main cusp strongly curved. One pair of lateral cusplets

sometimes with incipient outer pair present but short and

triangular. Root lobes in lateral teeth with wide and flat

basal face giving ‘swollen’ profile to posterior root lobe.

Description. The dentition of Roulletia canadensis sp. nov. shows

very pronounced monognathic and less pronounced dignathic

heterodonty. There is no evidence of sexual or significant


Figs 1–24. Roulletia canadensis sp. nov.; all ·6. 1–3, P2989.102, first lower anterior tooth. 1, labial view. 2, lingual view. 3, anterior

view. 4–6, P2989.89, third upper anterior tooth. 4, labial view. 5, lingual view. 6, anterior view. 7–9, P2989.88, second upper

anterior tooth. 7, labial view. 8, lingual view. 9, anterior view. 10, P2989.87, first upper anterior tooth, labial view. 11, P2989.103,

second lower anterior tooth, labial view. 12, P2989.95, fifth upper lateral tooth, labial view. 13–14, P2989.90, upper intermediate

tooth. 13, labial view. 14, lingual view. 15–17, P2989.104, holotype, third lower lateral tooth. 15, lingual view. 16, labial view. 17,

anterior view. 18, P2989.101, lower parasymphyseal tooth, labial view. 19–20, P2989.92, second upper lateral tooth. 19, labial

view. 20, lingual view. 21–22, P2989.110, lower posterior tooth. 21, labial view. 22, lingual view. 23–24, P2989.97, upper posterior

tooth. 23, labial view. 24, lingual view.


PLATE 5

UNDERWOOD and CUMBAA, Roulletia

21 3

4 56

7 89

10 11

13 1412

15

16 17

21 22

23 242019

18

ontogenetic heterodonty. Despite the heterodonty, characters

common to all teeth, or characters with intermediate morpho-

logies between extremes, allow all of the teeth to be assigned to

the same taxon. In all teeth the crown is completely unorna-

mented, and a cutting edge is continuous across the entirety of

the main and lateral cusps.

There are three anterior teeth in each side of the upper and

lower jaw, although the range of sizes of lower parasymphyseal

teeth suggests that the size and possibly even presence of the first

lower anterior teeth may be very variable. In all anterior teeth,

except for some lower parasymphyseal teeth, the main cusp

makes up at least half of the total height of the tooth. The first

upper and lower teeth are relatively symmetrical, but in all other

anterior teeth, the main cusp is inclined to the posterior or, in

the case of the third upper tooth, the cusp is erect but the ante-

rior root lobe is enlarged. The main cusp has a very faint sigmoi-

dal curvature, and in profile appears triangular with a regular

taper towards the apex. The labial face is almost flat and sepa-

rated from the very strongly convex lingual face by a weak but

continuous cutting edge. The labial face of the crown extends

below the base of the main cusp to between a third and half way

down the top of the root lobes. It is somewhat flared at the base

and overhangs the root. There is a single pair of small but robust

lateral cusplets on the lower teeth, but only very reduced or

incipient cusplets on the upper teeth. Cusplets are slightly diver-

gent and never reach as high as the base of the main cusp. All

anterior teeth have very clearly separated root lobes, which form

an internal angle of 90 degrees or less. The root lobes are roughly

parallel sides and are slightly labiolingually compressed. A some-

what flattened linguo-basal face is present, but there is no sharply

defined contact between this and the rest of the root. The root

lobes of all but the first files of teeth are somewhat asymmetrical,

having a more angular apex on the anterior lobe and a rounded

one on the posterior lobe. There is a swollen, but not strongly

projecting, lingual boss, which is bisected by a prominent but

shallow nutritive groove. A single foramen is present within the

nutritive groove, other foramina are restricted to the upper inte-

rior part of the root lobes and are only seen on a small number

of teeth. Lower parasymphyseal teeth are similar in many ways to

the rest of the anterior teeth, although about half the maximum

size and less symmetrical. They are rather variable in shape, with

some being very similar to the first lower anterior tooth, only

smaller and more anterior-distally compressed, with others being

more irregular in form with shorter cusps and strongly asymmet-

rical roots. Lateral cusplets may be absent or only present on one

side. In all cases, the strong nutritive groove is retained, aiding

the recognition of even highly distorted teeth.

Upper intermediate teeth are relatively uncommon within the

assemblage, possibly suggesting that only one was present in

each jaw, or even that they were not present in all individuals.

They are very variable in form, but are small, squat and usually

strongly asymmetrical. In most teeth, the main cusp is short and

triangular with a single lateral cusplet, often with an incipient

cusplet on the posterior side. The root has the same general

form as in anterior teeth but is short and swollen, often with

only one well-developed root lobe.

The probable first two upper and first lower lateral teeth have

a morphology which is intermediate between the anterior and

A Upper teeth, labial view

B Lower teeth, labial view

C Upper teeth, lingual view

D Lower teeth, lingual view

TEXT -F IG . 2 . Reconstructed dentition of Roulletia canadensis sp. nov. using adult teeth. Scale bar represents 10 mm. A, Upper

dentition in lingual view, specimens (left to right P2989.87–P2989.99). B, Lower dentition in lingual view, specimens (left to right

P2989.100–P2989.111). C, Same upper dentition in labial view. D, Same lower dentition in labial view.


remainder of the lateral teeth. The remainder of the lateral and

posterolateral teeth have a morphology that is quite distinct

from that of the anterior teeth. Lateral teeth are all strongly

asymmetrical with the main cusp strongly inclined or, on the

more posterior teeth, curved towards the posterior. Presumed

upper teeth are somewhat more compressed than lowers, with a

rather more ‘blade-like’ main cusp. In all lateral teeth the apex

of the main cusp reaches a point level with the posterior end of

the root. The main cusp is of a similar height to the root in all

but the posteriormost teeth, where it is somewhat shorter. The

base of the main cusp comprises somewhat over half of the total

width of the tooth, and in the majority of teeth is flanked by a

pair of short and triangular lateral cusplets. In some teeth from

both presumed upper and lower positions, incipient or very

small additional cusplets may be present, generally but not

always on the posterior side of the tooth. In posterolateral teeth,

the anterior lateral cusplet is commonly fused to the leading

edge of the main cusp to form a serration, or is absent alto-

gether. The labial face of all cusps is only slightly convex, and

there is typically a weak concavity at the base of the main cusp.

The lingual face of the cusps is more strongly convex than the

labial face, but all cusps are still distinctly labiolingually com-

pressed. The cutting edge separating labial and lingual crown

faces is well developed and continuous. The base of the crown

extends a short distance below the cusps on the labial face, with

very minor overhang of the root in the central part. The base of

the crown on the lingual face is gently arched over the root and

has a narrow but well-defined neck. The root of all lateral and

posterolateral teeth is strongly labiolingually compressed with a

wide and flat linguo-basal face. The root lobes are relatively

short, and the sharp angle between the linguo-basal edges of the

root lobes is from 90 to 110 degrees. The root lobes are of simi-

lar lengths, with a very well-rounded apex to the posterior lobe

and a somewhat more angular apex to the anterior lobe. A pro-

nounced shelf is present at the top of the root on the lingual

side of the tooth, and there is a sharp angle between this and

the root linguo-basal face. A well-developed nutritive groove

extends vertically across the entire root linguo-basal face.

Discussion. Teeth of Roulletia canadensis sp. nov. are

extremely common within the samples studied, and com-

prise the second most abundant chondrichthyan remains.

The reconstructed dentition gives a dental formula very

similar to that of Carcharias taurus, although differs from

it in lacking the small posterior teeth of C. taurus, and

probably in having less strongly compressed lower para-

symphyseal teeth. Teeth of R. canadensis sp. nov. are dis-

tinctly different from those of C. taurus, with greater

degree of heterodonty and more compressed and inclined

lateral teeth, further confirming the generic distinction.

Roulletia canadensis sp. nov. has teeth similar to those

of R. bureaui Vullo et al., 2007 from the Cenomanian of

France but differs in a number of respects. Teeth of

R. canadensis sp. nov. are more gracile and labiolingually

compressed. They have a less robust main cusp which is

more blade-like in lateral teeth, have wider lateral cusplets

and have a root which, in lateral teeth, is less strongly ‘V’

shaped and have wider and more rounded root lobes.

Despite these differences, the similarity in overall tooth

shape and heterodonty suggest that these two species are

congeneric. A second species that is very similar to

R. canadensis sp. nov. is ‘Carcharias’ amonensis (Cappetta

and Case, 1975) which is present elsewhere in North

America in the Cenomanian (e.g. Welton and Farish 1993;

Cappetta and Case 1999). Latero-posterior teeth of

‘C.’ amonensis and R. canadensis sp. nov. are very similar,

although teeth of R. canadensis sp. nov. have a more

curved main cusp and more rounded root lobes. Teeth

from other jaw positions are less similar, with R. canaden-

sis sp. nov. having a less erect main cusp and shorter lat-

eral cusplets in lateral teeth, and very much smaller lateral

cusplets and a complete cutting edge in anterior teeth.

Roulletia canadensis sp. nov. appears to have been

abundant within the northern part of the Western Inte-

rior Seaway, being common at a number of sites in cen-

tral Canada in addition to the one described here (SC,

pers. obs.). It is present, if previously unrecognized, in

the mid part of the Seaway (Shimada et al. 2006) where it

co-occurs with ‘Carcharias’ amonensis (Shimada et al.

2006, fig 9.3). R. canadensis sp. nov. has not been

recorded in Texas (Cappetta and Case 1975, 1999; Welton

and Farish 1993) where ‘C.’ amonensis is common. In

France, ‘Carcharias’ amonensis and R. bureaui are both

known but do not occur at the same stratigraphical levels.

Current records, therefore, suggest that R. canadensis sp.

nov. was a cool-water taxon, possibly endemic to the

northern WIS.

Family ARCHAEOLAMNIDAE fam. nov.

Derivation of name. From Archaeolamna Siverson, 1992, the

genus used to diagnose the family.

Diagnosis. Family known only from disassociated teeth.

Dentitions with well-developed ‘lamniform’ heterodonty

with distinct tooth morphologies in different jaw posi-

tions. Dentitions comprise three upper anterior and typi-

cally three lower anterior teeth. Small and variously

‘stunted’ teeth are present in upper parasymphyseal, lower

parasymphyseal and upper intermediate positions. No

distinct morphological break between lateral and poster-

ior teeth in upper and lower jaws, and largest teeth of

dentition in lateral positions. Teeth of typical lamniform

morphology with ‘V’ or ‘U’ shaped root and erect cusp

flanked by smaller cusplets. Crown ornament weak, irreg-

ular or absent. Lingual neck of crown narrow but well

defined. Teeth with serrations or cutting morphology are

unknown. Root large and dense, with the only well-devel-

oped foramen on apex of lingual bulge or within nutritive

groove. Nutritive groove absent, small or shallow. Teeth


with anaulacorhize vascularization restricted to large or

posterior teeth of taxa where a large foramen is typically

present.

Included taxa. Archaeolamna is the genus from which the family

is diagnosed. In addition, there are several other genera with

similar overall tooth morphology but within which the dental

formula is unknown. Archaeolamna is known from Albian to

Maastrichtian strata (Siverson 1996). Teeth of Cretodus Sokolov,

1965 are very similar to those of Archaeolamna, differing largely

in their much stronger ornament, probably lesser heterodonty

and greater maximum size. Cretodus is known from Cenomanian

through Campanian strata (Schwimmer et al. 2002). Teeth of

Dallasiella Cappetta and Case, 1999 are also very similar to those

of Archaeolamna, differing mainly in the greater compression of

the roots of lateral teeth, and this may also be a member of the

Archaeolamnidae fam. nov. Dallasiella is reported from Ceno-

manian to Coniacian strata (Cappetta and Case 1999; Cumbaa

et al. 2006; Cook et al. 2008). Inferred presence of the same

dental formula suggests that Telodontaspis gen. nov. (see below)

may also be included into the Archaeolamnidae fam. nov. Teeth

of Protolamna Cappetta, 1980a, included into the Eoptolamnidae

by Kriwet et al. (2008), also have a number of similarities to the

anterior teeth of Archaeolamna. Despite this, morphology of

teeth of other positions, and the presumed dental formula, of

known species of the Eoptolamnidae readily differentiate the two

families. The known range of the Archaeolamnidae fam. nov. is,

therefore, Albian to Maastrichtian and was apparently globally

distributed.

Remarks. The dental formula of Archaeolamna differs

from that of all other known Cretaceous and Cenozoic

lamniforms in possessing teeth in lower parasymphyseal,

upper parasymphyseal and intermediate tooth positions

(of Cappetta 1987), associated with three large upper

anterior teeth. Within Cretaceous lamniforms, upper

parasymphyseal teeth are present within Cretoxyrhina

(Siverson 1996; Shimada 1997), Cretalamna (Shimada

2007) and Cardabiodon (Siverson 1999; where the indi-

cated first upper anterior tooth may also represent a

parasymphyseal), indicating their presence within the

Cretoxyrhinidae Glickman, 1958, Otodontidae Glickman,

1964 and Cardabiodontidae Siverson, 1999, respectively,

whilst lower parasymphyseal teeth are either absent in all

three taxa, or possibly present only in Cretoxyrhina (Shi-

mada 1997). Intermediate teeth (sensu Cappetta 1987,

defined as stunted teeth growing on the bar between the

upper anterior and lateral hollows) are absent in all three

species, with the intermediate teeth of Shimada (1997,

2007) here considered as third upper anterior teeth. All

three of these tooth positions are absent in extant Lamni-

dae Muller and Henle, 1838.

Within the extant Odontaspididae Muller and Henle,

1839 s.l., upper parasymphyseal teeth are present in

Odontaspis ferox (Risso, 1810) but absent in O. noronhai

(Maul, 1955) and Carcharias taurus Rafinesque, 1810.

Lower parasymphyseal and intermediate teeth are present

in all three species, but in O. ferox the intermediate teeth

are especially numerous and preceded by only two files of

large upper anterior teeth, in contrast to the three of

almost all other lamniforms.

The apparently unique presence of all tooth families

within Archaeolamna suggests that the tooth formula is

the least derived, with progressive loss of files of small

teeth in more derived lamniform families, until in the

Lamnidae all of these ‘small’ teeth are lost and the third

upper anterior tooth is severely reduced.

Genus ARCHAEOLAMNA Siverson, 1992

Type species. Odontaspis kopingensis Davis, 1890 from the Camp-

anian of Sweden.

Archaeolamna ex. gr. kopingensis (Davis 1890)

Text-figures 3A–D, 4A–R

1990 Cretodus sp. Case et al., p. 1090, fig. 7a–f.

1996 Archaeolamna aff. kopingensis (Davis, 1890);

Siverson, p. 825, pl. 2, figs 1–6.

1997 Archaeolamna sp. Siverson, p. 462, fig. 4A–H.

1999 Carcharias sp. Cumbaa and Tokaryk, p. 61, fig. 5

(pars; upper 3 teeth centre right column).

2001 Cenocarcharias tenuiplicatus (Cappetta and Case);

Case, pl. 2, figs 4, 6.

?2001 ?Carcharias amonensis (Cappetta and Case); Case,

pl. 2, fig. 7.

2006 Archaeolamna sp. Cumbaa et al., p. 146, fig. 4.10.

2006 Cretodus semiplicatus (Munster in Agassiz); Cumbaa

et al., p. 146, fig. 4.11.

2006 Archaeolamna cf. A. kopingensis (Davis, 1890);

Shimada et al. p. 15, fig. 10.1.

2008 Dallasiella willistoni Cappetta and Case; Cook et al.,

p. 1192, fig. 5B.

2008 Archaeolamna cf. A. kopingensis (Davis, 1890); Cook

et al., p. 1192, fig. 5C.


P2989.140.

Description. The assemblage of teeth of Archaeolamna ex. gr.

kopingensis shows very varied morphologies, revealing strong

monognathic and weak dignathic heterodonty (see above), as

well as some ontogenetic and probable sexual heterodonty.

Within the tooth assemblage, most of the teeth are reasonably

small, with a small number of larger teeth (as used in the denti-

tion reconstruction) and a very small minority of teeth that are

at least 50% larger than average. The very largest teeth differ

from others in that there are commonly strong but short and

irregular longitudinal folds at the base of the labial face of the

crown, especially prominent in teeth from posterolateral


positions. Larger teeth of all anterior and anterolateral tooth

positions appear to be present in both a robust and a gracile

morph. These have the same overall shape but the main cusp

and the root lobes of the gracile morph are considerably more

slender than in the robust morph. The main cusp of the gracile

teeth is also somewhat longer for the width of the tooth than in

the robust morph. By analogy with some modern lamniforms

and carcharhiniforms, it is probable that the gracile morph

represents teeth of adult male individuals, whilst the robust

morph represents females and immature individuals.

Anterior teeth have a main cusp that is rather higher than the

root and a single pair of slightly divergent lateral cusplets. The

main cusp is robust and tapers steadily to a point. In lower

anterior teeth and presumed first upper anterior teeth, the main

cusp is straight and vertical, becoming inclined in some upper

anterior teeth (file two) and curved in others (file three). The

lateral profile of the main cusp shows a very slight sigmoidal

curvature. In all anterior teeth the lateral cusplets on anterior

and posterior sides of the tooth are of similar size, and are

rather higher than wide. The crown unites the main and lateral

cusplets at the base on the labial side, but not on the lingual

face, where a narrow neck is present at the base of each of the

cusps. The labial face of the cusps is faintly convex, but com-

monly flat or slightly concave at the base of the main cusp. The

lingual face of all cusps is strongly convex, giving them a rather

semicircular cross-section. A well-defined cutting edge is contin-

uous across all cusps. The root is bulky and strongly ‘V’ shaped.

The root is somewhat asymmetrical in all anterior teeth, with

the asymmetry varying with tooth position. The root lobes form

an internal angle of 90 degrees or less, depending on jaw posi-

tion. Root lobes are oval in cross-section, largely compressed an-

tero-distally, but in the posterior lobe this may be twisted

towards the lingual side. The terminations of the root lobes are

variable in shape, ranging from smoothly rounded to sharply

pointed, but are never strongly flattened. The linguo-basal base

of the root is not strongly flattened. There is a rather inflated

root lingual boss, and in the centre of this is either a single well-

developed foramen or a cluster of up to four small foramina. In

a small proportion of smaller teeth, the main foramen is within

a short but deep groove.

Lower parasymphyseal teeth are very variable but are essen-

tially modified anterior teeth. There appears to be a morphologi-

cal continuum between first lower anterior teeth and highly

modified and stunted parasymphyseal teeth. It is, therefore,

likely that the dentition at the front of the lower jaw is less

clearly defined than in other lamniforms. The crown of lower

parasymphyseal teeth differs from that of other anterior teeth

largely in being smaller relative to the root and less symmetrical,

with lateral cusplets often being better formed on one side of

the tooth than the other, or even absent on one or both sides.

The root is antero-distally compressed with a very well-devel-

oped lingual boss. Root lobes are short and rarely of close to

equal length; in many of the smaller teeth, only a single root

lobe is fully developed.

A Upper teeth, labial view

B Lower teeth, labial view

C Upper teeth, lingual view

D Lower teeth, lingual view

TEXT -F IG . 3 . Reconstructed dentition of Archaeolamna ex. gr. kopingensis (Davis 1890) using large teeth of the robust (?female)

morph. Scale bar represents 10 mm. A, Upper dentition in lingual view, specimens (left to right P2989.112–P2989.125). B, Lower

dentition in lingual view, specimens (left to right P2989.126–P2989.138). C, Same upper dentition in labial view. D, Same lower

dentition in labial view.


Presumed upper parasymphyseal teeth vary in shape but the

majority are relatively symmetrical; other teeth are of similar

overall morphology but are distorted and show greater asymme-

try. These are less abundant than lower parasymphyseal and

upper intermediate teeth and may not have been present in all

individuals: there is considerable variation in the presence of

these small teeth between individuals of many extant lamniforms

(CJU, pers. obs.). The main cusp is robust and rather triangular,

although in some of the more asymmetrical teeth, the basal part

may be parallel sided. Lateral cusplets are short, triangular,

robust and slightly divergent. The shape of the root is rather

variable, probably related to whether there were one or more

teeth within this jaw position. In the more symmetrical teeth,

the root is clearly ‘V’ shaped and relatively robust. The root

lobes show very little tapering and have an internal angle of

about 80 degrees. There is a swollen lingual region but not as

A

B

C

D

E

FG

H

I

NML

J

K

O

Q P R

TEXT -F IG . 4 . Archaeolamna ex. gr. kopingensis (Davis 1890) A–K · 6; L–R · 4.5. A, P2989.112, upper parasymphyseal tooth, labial

view. B–C, P2989.116, upper intermediate tooth. B, labial view. C, lingual view. D, P2989.113, first upper anterior tooth, labial view.

E, P2989.123, upper posterolateral tooth, labial view. F–G, P2989.126, lower parasymphyseal tooth. F, labial view. G, lingual view. H–I,

P2989.137, lower posterolateral tooth. 8, labial view. 9, lingual view. J–K, P2989.135, lower lateral tooth. J, labial view. K, lingual view.

L–N, P2989.130, first lower lateral tooth. L, labial view. M, anterior view. N, lingual view. O–P, P2989.118, second upper lateral tooth.

O, labial view. P, lingual view. Q, P2989.139, third or fourth upper lateral tooth showing strong ornament, labial view. R, P2989.140,

gracile morph second or third upper lateral tooth, labial view.


enlarged as in most anterior teeth, and the root lobes are oval in

cross-section without a well-defined linguo-basal face of the

root. In the remainder of the teeth from this proposed position,

the root is more compressed antero-posteriorly, creating a larger

lingual bulge. The root lobes are short and not often well

defined, comprising considerably less than half of the height of

the root.

Upper intermediate teeth are common within the assemblage,

and it is, therefore, likely that several files of these were present

in the jaw. They are symmetrical and have an erect and triangu-

lar main cusp flanked by a pair of slightly divergent cusplets. In

respects other than size, the crown of these teeth resembles that

of lower anterior teeth. The root is strongly ‘V’ shaped and has

an internal angle of 90 degrees or less. The root comprises about

half of the height of the tooth. The root is variably compressed

labiolingually. In some teeth, the root lobes are oval in cross-sec-

tion with a slightly flattened linguo-basal root base, whereas in

other teeth the linguo-basal face of the root is very flattened,

even including the region directly below the main cusp. This

flattening extends to the root lobes, which are about twice as

wide as they are thick. The lingual foramen is present but very

small. In addition, there are a very small number of probable

upper intermediate teeth that are small and squat. A triangular

main cusp is compressed labiolingually and flanked by a pair of

lateral cusplets that are similar in shape to those of lower lateral

teeth. The lingual face of the crown is wide at the base and is

either smooth or ornamented with irregular wrinkles similar to

those seen in other teeth. The lingual face of the crown is

smooth other than a very well-developed neck.

Upper lateral and posterior teeth all have a similar morphol-

ogy, varying largely in their size and the height of the cusps.

The first upper lateral tooth has a morphology somewhat inter-

mediate between that of the anterior teeth and the remaining

lateral teeth. The main cusp is robust and has a smooth curve

along both anterior and posterior edge. In all but in the small-

est posterior teeth, the main cusp is of similar height to the

root. The axis of the main cusp forms an angle of about 60

degrees with the base of the tooth. There is a single pair of

robust lateral cusplets of similar size to each other which are

slightly higher than wide. These are slightly divergent, but in

more posterolateral teeth, the posterior lateral cusplet is often

more erected than the main cusp. In the most posterior teeth,

the anterior cusplet may be reduced or incipient. The labial face

of the crown is smooth and slightly convex, although on some

very large teeth and some posterolateral teeth, small vertical

wrinkles may be present just above the crown-root junction.

The three cusps are united by a narrow basal strip of enameloid

on the labial side of the tooth, but not on the lingual side.

There, a very prominent neck is present at the base of each of

the cusps. The lingual face of the cusps is smooth and strongly

convex. There is a well-developed cutting edge across all of the

cusps. The root of upper lateral teeth is bulky and quite sym-

metrical, and the rather stubby root lobes form an internal

angle of 90–100 degrees. The outer edge of the anterior root

lobe continues from the edge of the main cusp, with a rounded

termination. The labial face of the root slopes gently away from

the base of the crown, and there is no labial crown overhang.

The linguo-basal face of the root is slightly flattened, with no

clear edge to the face. The lingual boss is large and rounded,

with one or sometimes two or three foramina at the apex. In

some smaller teeth, a very short but deep groove is present.

Some small foramina are seen on the upper parts of the root

labial face, but are rarely conspicuous.

Lower lateral teeth are very close to symmetrical, with the

exception of the probable first lower tooth, which is very similar

in shape to the third anterior tooth, and the smaller posterolat-

eral teeth. The main cusp is straight and quite short, with

slightly concave outer edges. There is a single pair of relatively

large lateral cusplets, that are higher than wide. The base of the

lateral cusplets is in line with the base of the main cusp, as

opposed to being some way down the outer edge of the root

lobes as in teeth from other positions in the jaw. The outer edge

of the cusplets overhangs the root slightly, and in some postero-

lateral teeth this projection develops into an additional incipient

cusplet. The labial face of the crown is very slightly convex to

almost flat, and has no ornament in the vast majority of teeth.

The basal edge of the enameloid on the labial side is gently

arched, as opposed to the strong curvature on other teeth. The

lingual face of the cusps is smooth and strongly convex, with a

well-developed neck at the base of each of the cusps. In poster-

ior teeth, the main cusp is strongly inclined as in the upper

teeth, and upper and lower teeth can only be differentiated by

the shape of the root. The root of lower lateral teeth is far more

‘square’ than on teeth from other positions; viewed lingually, the

top of the root is only slightly arched upwards, and the edges of

the root lobes are almost vertical below the outer edges of the

lateral cusplets, giving a very sharp angle between these edges.

The inner edges of the root lobes form a smooth semicircle in

most teeth, becoming more angular in posterior teeth. The root

lobes themselves have rounded terminations and are somewhat

flattened labiolingually. The labial face of the root smoothly

curves away from the crown, with a slight recess below the base

of the main cusp. The linguo-basal face of the root is large,

making up almost all of the root that can be seen in lingual

view, and relatively flat. There is a distinct but not sharply

angled edge to this face. The lingual boss projects slightly, giving

a narrow horizontal shelf below the cusps. There are one or

more foramina at the apex of the lingual boss, and in some

smaller teeth these are opened out to form a short but distinct

groove. Small foramina are present towards upper part of

the labial face of the root, but are small and irregularly

distributed.

Discussion. Archaeolamna is known from the Albian to

Maastrichtian and appears to have had a virtually global

distribution (see Siverson 1996). Of these occurrences, the

majority of records relate to Archaeolamna kopingensis

(Davis, 1890), although stratigraphical variations suggest

that this may represent a group of closely related taxa

rather than a single species. In addition to A. kopingensis

s.l., A. haigi Siverson, 1996 from the Cenomanian of Aus-

tralia and A. kopingensis judithensis Siverson, 1992 from

the Campanian of the USA (the latter probably deserving

of specific rank) are known.


Despite the very high degrees of heterodonty present, it

is possible to make general comparisons between the

Archaeolamna kopingensis s.l. specimens described here

and from other populations. Albian specimens from

Europe (Biddle 1993) are typically rather gracile and pos-

sess a poorly formed nutritive groove in most or all teeth.

Albian specimens from Australia (Siverson 1997) are

similar, but the nutritive groove is restricted to smaller

teeth. Archaeolamna kopingensis s.l. specimens from the

Cenomanian of Australia (Siverson 1996) and probably

France (Vullo et al. 2007), as well as younger occurrences,

lack a nutritive groove and possess weak folds on the

labial face of the larger teeth. The specimens described

here are therefore most similar to those from the Austra-

lian Albian, differing only in the possession of weak

ornament on the labial face of a small number of the very

largest and most posterior teeth. Although there are slight

differences between different populations of A. kopingen-

sis, it has not been possibly to produce a reliable set of

criteria for separating species within what almost certainly

represents a complex of morphologically similar taxa.

Within the ‘mid’ Cretaceous, A. kopingensis s.l. is wide-

spread but not global in occurrence. It is common at this

site and elsewhere in the Cenomanian of central Canada

(SC, pers. obs.) as well as in Colorado (Shimada et al.

2006). It is also present in western Europe (e.g. Biddle

1993; Vullo et al. 2007; CJU, pers. obs.), Russia (CJU,

pers. obs. of specimens mislabelled as other species) and

Australia (Siverson 1996, 1997). Despite this, it has not

been recorded in Texas (e.g. Welton and Farish 1993;

Cappetta and Case 1999) or elsewhere in areas associated

with Tethys. It, therefore, appears to have been a temper-

ate water inhabitant, present in both Northern and

Southern Hemispheres.

Family ?ARCHAEOLAMNIDAE fam. nov.

Genus TELODONTASPIS gen. nov.

Type species. Telodontaspis agassizensis sp. nov.

Derivation of name. From the spear-like tooth morphology and

an Odontaspis-like overall tooth shape.

Diagnosis. Strong monognathic and dignathic heterodont

dentition with anterior teeth up to 12 mm high. Several

files of upper and lower parasymphyseal teeth and upper

intermediate teeth present. Cusp unornamented, slender

and straight, at least 3 times as high as wide, inclined to

posterior in lateral teeth and faintly labiolingually sigmoi-

dal in anterior teeth. Single pair of small, triangular, lat-

eral cusplets present in upper lateral teeth, absent in all

other teeth. Base of crown with prominent neck on lin-

gual side, and extends along upper third to half of root

lobe on labial side. Cutting edge continuous in lateral

teeth but not reaching base of crown on anterior teeth.

Crown does not overhang root. Root with two clearly

defined lobes, of roughly equal size in lower teeth, but

with anterior lobe longer than posterior in upper teeth.

Lingual face of root with poorly developed lingual protu-

berance, below which root lobes are either labiolingually

compressed with a flat linguo-basal root face in upper

lateral teeth, or somewhat expanded lingually with no

clearly defined linguo-basal root face. There is a well-

developed round to slightly elongate foramen at the apex

of the lingual protuberance, with very small foramina

spread across the root surface.

Remarks. The relatively small number of teeth assigned to

the single known species of this genus, and the high

degree of heterodonty, make reconstruction of the denti-

tion less certain than with some other taxa present in this

assemblage. This is made more difficult by the presence

of different proportions of teeth in the fossil assemblage

than would be expected in the jaw of a living individual,

probably because of a combination of differential shed-

ding rates, a range of ontogenetic stages being present

and likelihood of random bias in a small sample size. The

teeth collected comprise a relatively large number of teeth

assigned to parasymphyseal files, and relatively few teeth

considered to be lower lateral positions. It is possible that

more material would require a different reconstruction of

the dentition to be developed. Despite this, it is evident

that the overall dental formula is similar to that of

Archaeolamna, with three upper anterior tooth positions,

upper and lower parasymphyseal teeth, and upper inter-

mediate teeth all being present. In addition, there appears

to be a morphological gradation from lower parasymphy-

seal to lower anterior teeth, as seen in Archaeolamna.

Despite this, the number of other lower and upper para-

symphyseal teeth suggest that multiple files of these were

present in life, a character present in lower jaws of Odon-

taspis noronhai but not present in the upper jaw of other

known lamniforms. The overall tooth shape is not unlike

that of Cretoxyrhina mantelli (Agassiz, 1843), but Tel-

odontaspis differs in possessing lower parasymphyseal and

upper intermediate teeth and a more strongly developed

heterodonty within the upper jaw. Teeth of T. agassizensis

sp. nov. are similar in overall morphology to teeth of neo-

nate individuals of Cretoxyrhina mantelli, and have previ-

ously been mistaken for that species. Despite this, teeth of

T. agassizensis sp. nov. differ in the range of tooth mor-

phologies present within the dentition, most of which

clearly do not fit in with the ontogenetic trend of C. man-

telli. Teeth are similar to those of Priscusurus adrupto-

dontus Kriwet, 2006, although this genus and species was


based on a very small sample of material, and so remains

poorly defined. Teeth of T. agassizensis sp. nov. differ from

those of P. adruptodontus in having a more slender main

cusp and, in upper lateral teeth, small lateral cusplets.

Telodontaspis agassizensis sp. nov.


2006 Cretoxyrhina mantelli (Agassiz)(?); Shimada et al.,

p. 15, fig. 10.11–10.12.

Derivation of name. From the locality of the type material being

close to the shoreline of glacial Palaeolake Agassiz.


Additional material. Forty-four teeth studied including P2989.

141–P2989.143; P2989.145–P2989.152.

Diagnosis. As for genus.

Description. The teeth of this species are very varied in shape

but occur in a number of discrete morphologies relating to posi-

tions within the jaw. The relatively small number of teeth pre-

vents the construction of a full dentition, and as a result, tooth

positions are partly inferred by comparison with other taxa.

There are two different morphologies of parasymphyseal teeth

(Pl. 6, figs 12–13, 18–20), with the commoner, often more asym-

metrical, teeth being considered here to come from the upper

dentition. These presumed upper parasymphyseal teeth have a

straight cusp that is up to half the total height of the tooth. The

cusp is straight and slender and, in labial view, tapers steadily

towards the apex. It is unornamented in all teeth. There is a very

slight lingual curvature in some teeth. The labial face of the cusp

is gently convex, separated from the strongly convex lingual face

by a narrow cutting edge, which is continuous in some teeth,

but only present on the upper half of either the anterior or pos-

terior edge of the cusp on others. There is a well-developed lin-

gual neck at the base of the cusp. The basal edge of the crown

on the labial side of the tooth is extended along the root lobes,

extending further along the anterior than posterior lobe. The

crown basal edge is flat and does not noticeably overhang the

root. On the majority of teeth, the cutting edge does not extend

along this basal extension of the crown. A small proportion of

teeth have an incipient cusplet on the mesial side of the crown.

There are two distinct root lobes, the posterior one being about

half the length of the anterior in the more asymmetrical teeth.

The anterior root lobe has a rounded apex, whilst that of the

posterior is usually more pointed. The labial face of both root

lobes is slightly concave and merges with the base of the crown,

There is a narrow shelf below the base of the crown on the lin-

gual side, terminating in a pointed protuberance with a well-

developed foramen at the apex. Below this, the root is strongly

labiolingually compressed and the linguo-basal root face is flat

to slightly concave. Small foramina are present over the entire

root surface.

Teeth referred to lower parasymphyseal positions are rather

different. The cusp is slender and is curved lingually and

slightly twisted to the posterior. The cutting edge is continuous

on the anterior edge, but does not reach the base on the pos-

terior side of most teeth. There is a pair of incipient cusplets

at the base of the cusp. The base of the crown is straight on

both faces, with a well-developed lingual neck. The labial face

of the crown does not overhang the root. The root is relatively

bulky, with two root lobes that form an angle of up to 90

degrees. Both root lobes are tapered and have variable rounded

terminations. The root lobes are not compressed in either ori-

entation, and the linguo-basal root face is convex. The root is

swollen below the lingual base of the crown and has a some-

what slit-like foramina at the apex. Small foramina are present

over the remainder of the root surface. Some teeth have a mor-

phology intermediate between this and presumed lower anterior

teeth, differing from the latter by being smaller and having

longer root lobes.

All of the anterior teeth have an elongate and slender cusp

that is higher than the root, and lateral cusplets are absent,

although an incipient distal cusplet is present on the presumed

third upper tooth. The cusp is weakly sigmoidal in all teeth, but

in labial view, is either straight or, in the probable first upper

teeth, very gently curved. It is inclined to the posterior in lower

and first upper anterior teeth, but inclined to the posterior in

the other upper anteriors. In the presumed first and second

lower teeth, and to a lesser extent other anterior teeth, the labial

face of the cusp narrows towards the base, with the cutting edges

moving onto the crown labial surface. At the base of the crown

is a well-developed neck in the lingual side, whilst on the labial

side the crown enameloid extends for about a third of the length

of the upper edge of the root lobes, the crown merging with the

root labial face without any overhang. There is a continuous

cutting edge which does not reach the crown base in any teeth.

The root is robust in all anterior teeth, but more gracile and

labiolingually compressed in the second and third upper teeth.

The root of lower anterior teeth is relatively expanded lingually,

resulting in a well-developed lingual protuberance. This has a

well-developed foramen at the apex. In some lower anterior

teeth, the root is incompletely developed, but the root lobes are

seen to be very short and stubby, considerably less than half the

total height of the root and both are of similar size and shape

with a rounded root lobe apex. In the third lower teeth, the root

lobes are somewhat longer and asymmetrical, with a more

pointed anterior root lobe apex and more rounded posterior

apex. There is a somewhat flattened area on the linguo-basal face

of the distal root lobe, but otherwise this face is not differenti-

ated. The upper anterior teeth have well-defined root lobes that

are asymmetrical, with the anterior lobe being longer than the

posterior. The root is expanded to form a lingual protuberance,

but this is not as distinct as in the lower teeth. The profile of

the root of the three presumed upper anterior teeth is rather dif-

ferent; in the first upper, the root lobes are short, and the ante-

rior lobe somewhat recurved to the posterior, whilst the roots of

the second and third teeth are strongly asymmetrical with a

longer anterior lobe. The root of the presumed third upper

tooth is somewhat more labiolingually compressed than that of

other anterior teeth, and the linguo-basal root face is more


clearly differentiated and flatter, thus resembling the root of the

upper lateral teeth.

Teeth presumed to be from upper lateral positions show some

morphological variation, with the first upper anterior being

clearly differentiated from the rest. Upper lateral teeth are

strongly asymmetrical, with the cusp strongly inclined to the

posterior. The cusp comprises up to half of the total height of

the tooth, being slender, straight and tapering smoothly to the

tip. There is no lingual curvature other than in the probable an-

teriormost teeth, where there is a gentle sigmoidal curve. The

labial face of the cusp is almost flat, and a continuous cutting

edge is present. At the base of the main cusp is a pair of very

small to (in the anteriormost teeth) incipient lateral cusplets,

which are triangular in profile and of similar size in both ante-

rior and posterior positions. The lingual face of the crown is

convex, nearly semicircular in section in most teeth but more

lingually expanded in the anteriormost teeth. There is a clear lin-

gual neck. The labial face of the crown extends along about half

of the upper edge of the root lobes, being flat and merging with

the root labial face. The root lobes are asymmetrical, becoming

less so in more posterior teeth. The anterior root lobe it slender

and parallel sided, with a rounded or slightly pointed apex. The

posterior root lobe is typically about half the length of the ante-

rior, and has a more angular termination. In the anteriormost

teeth, the most distal part of the posterior root lobe is twisted

lingually. The root is at its widest at the point of a poorly devel-

oped lingual protuberance, and then tapers gradually towards

the tips of the root lobes, resulting in the root lobes being very

labiolingually compressed and having a wide and flat linguo-

basal root face. The root of the anteriormost teeth is of the same

general shape, but with very little labiolingual compression,

resulting in a far more robust root. There is a prominent foram-

ina on the lingual protuberance, and small foramina are present

across the surface of the root of all teeth.

Upper intermediate teeth are similar in overall shape to those

from the mid part of the upper lateral files. They differ in being

smaller, reaching about half the maximum size, having a more

robust main cusp and having a pair of well-developed lateral

cusplets. Anterior and posterior cusplets are of similar size and

triangular in profile.

Presumed lower lateral teeth are in many respects similar to

anterior teeth. The teeth are relatively symmetrical, except in

posterior files where they are rather inclined to the posterior.

The cusp is straight and slender, with a very slight sigmoidal

curvature and comprises about half of the total height of the

tooth. The cusp labial face is weakly convex, and separated from

the strongly convex lingual face by a narrow but continuous cut-

ting edge. There are no lateral cusplets, and the base of the labial

face of the crown extends over the upper part of the root lobes,

where there is no basal overhang. There is a clear neck at the

lingual base of the crown. The outer edges of the root lobes

extend almost in continuation of the angle of the outer edges of

the cusp, giving the teeth a rather compressed ‘Y’ shaped profile.

The root lobes are clearly separated and rather gracile and paral-

lel sided. There is a well-developed lingual protuberance, and

below this the lingual side of the root lobes are somewhat

expanded lingually, with no clearly defined linguo-basal root

face. There is a single, well-developed, foramen at the apex of

the lingual protuberance, and numerous small foramina else-

where on the root.

Remarks. Teeth of Telodontaspis agassizensis sp. nov. are

present in the Cenomanian of Colorado (Shimada et al.

2006), and it is considered likely that this species has been

under recorded because of confusion with teeth of juve-

nile Cretoxyrhina.

Family ANACORACIDAE Casier, 1947

Genus SQUALICORAX Whitley, 1939

Type species. Corax pristodontus Agassiz, 1843 from the Maas-

trichtian of the Netherlands.

Squalicorax curvatus (Williston, 1900)

Plate 7, figures 1–23; Plate 8, figure 2

1900 Corax curvatus Williston pl. 30, figs 7–8.

1990 Squalicorax falcatus (Agassiz); Case et al., p. 1091,

fig. 10a–p, p. 1092, fig. 11a–b.

?1993 Squalicorax curvatus (Williston, 1900); Welton and

Farish, p. 116, figs 3–4.

1993 Squalicorax falcatus (Agassiz); Williamson et al.,

p. 457, fig. 7.4–7.5.

1999 Squalicorax sp. (group falcatus); Cappetta and Case,

p. 63, pl. 6, figs 4–9.


Figs 1–27. Telodontaspis agassizensis sp. nov.; all ·4.5. 1–2, P2989.141, ? lower parasymphyseal tooth. 1, labial view. 2, lingual view.

3–5, P2989.142, ? first upper anterior tooth. 3, labial view. 4, anterior view. 5, lingual view. 6–8, P2989.143, ? first upper lateral

tooth. 6, labial view. 7, anterior view. 8, lingual view. 9–11, P2989.144, holotype, ? third upper anterior tooth. 9, anterior view.

10, labial view. 11, lingual view. 12–13, P2989.145, ? upper parasymphyseal tooth. 12, labial view. 13, lingual view. 14–15,

P2989.146, ? upper intermediate tooth. 14, labial view. 15, lingual view. 16–17, P2989.147, ? upper lateral tooth. 16, lingual view.

17, labial view. 18–20, P2989.148, ? lower parasymphyseal tooth. 18, labial view. 19, anterior view. 20, lingual view. 21–22,

P2989.149, ? lower posterior tooth. 21, labial view. 22, lingual view. 23–24, P2989.150, ? second lower anterior tooth. 23, labial

view. 24, lingual view. 25–26, P2989.151, ? third upper anterior tooth of juvenile. 25, labial view. 26, lingual view. 27, P2989.152,

? incomplete first lower anterior tooth, labial view.


PLATE 6

UNDERWOOD and CUMBAA, Telodontaspis

21

3 4 5

8

76

9

1011

12

13

14 15

1617

18 1920

2122

23 2425

26

27

1999 Squalicorax curvatus (Williston); Cappetta and

Case, p. 65, pl. 7, figs 6–8.

1999 Squalicorax sp. Cumbaa and Tokaryk, p. 61, fig. 5

(pars; 5 teeth in right 2 columns).

?2001b Squalicorax sp. cf. S. curvatus (Williston);

Cicimurri, p. 185, fig. 5g.

2006 Squalicorax falcatus (Agassiz); Cumbaa et al.,

p. 146, fig. 4.9.

2006 Squalicorax curvatus (Williston); Shimada et al.,

p. 9, fig. 8.2–8.4.

2006 Squalicorax falcatus (Agassiz); Shimada et al., p. 9,

fig. 8.5–8.9.

2006 Squalicorax sp. Shimada et al., p. 9, fig. 8.10–8.14.

2008 Squalicorax sp. Cook et al., p. 1189, fig. 5B.


P2989.166.

Description. Teeth of this species are up to 14 mm wide and

show considerable gradient monognathic heterodonty as well as,

in anterior files, dignathic heterodonty. By comparison with

modern lamniform and carcharhiniform sharks, it is presumed

that teeth with more slender and erect cusps which are associ-

ated with a more swollen labial overhang with a somewhat ‘W’

shaped basal edge of the crown are from lower anterior posi-

tions.

The crown of the teeth varies from 75 to 200 per cent as

wide as high depending on jaw position, with only extreme

anterior teeth being higher than wide. The crown comprises a

main cusp and a small but clearly defined distal heel, the latter

being between one fifth and one-quarter of the total width of

the tooth. The main cusp is never symmetrical, other than in

some parasymphyseal teeth, and is inclined to the posterior to

a varying degree. The labial face is faintly convex, with a

strongly convex lingual face, neither with any ornamentation.

The anterior edge of the main cusp is very variable in shape.

In most teeth, the basal part of the anterior edge is straight

and at a lower angle than the bulk of the edge, with a clear

angular contact between the two parts of the edge. In pre-

sumed lower teeth, this basal section is shorter and less well

defined than in upper teeth. After this the anterior cusp edge

ranges from straight to clearly convex, but is faintly convex in

most teeth. The apex of the cusp typically forms and angle of

50–60 degrees. The posterior edge of the cusp is straight to

slightly convex and varies from near vertical (in lower anterior

teeth and some larger posterolateral teeth) to strongly over-

hanging (in most teeth). Only rare presumed upper anterolat-

eral teeth have the cusp apex reaching beyond the posterior

margin of the rest of the tooth. The distal heel is low and has

a straight upper edge and convex posterior edge. There is a

sharp angle between this and the main cusp of between 80 and

125 degrees, only being less than 90 degrees in some lower lat-

eral teeth. Continuous serrations are present over the cusp and

distal heel; these get smaller towards the tooth apex but are

otherwise very regular, with between 5 and 7 serrations per

millimetre. The serrations are roughly semicircular in profile

and symmetrical, with no sign of secondary serrations. The

base of the labial face of the crown extends down over

the upper third to half of the root. In presumed upper teeth,

the labial base of the crown clearly overhangs the root with a

straight to slightly concave basal edge, without flaring towards

the base. The base of the labial crown face of lower teeth

extends further in the anterior and posterior parts of the tooth

than in the centre, giving a rather ‘W’ shaped profile in some

teeth. There is a prominent overhang along all of the labial

crown base, but it is particularly evident where the crown

reaches its lowest points, where the crown edge is flared labi-

ally to form a narrow ledge. The lingual base of the crown has

a very obvious neck, which is of a relatively constant height

across the width of the tooth. The roots of all teeth are close

to symmetrical and are robust and thick. The root lobes are

poorly defined, with an angle of 100–140 degrees between the

anterior and posterior parts of the root. The root is of similar

width to the crown, but the relative width of root and crown

differ greatly with jaw position. The ends of the root lobes are

commonly rounded, but the anterior root lobe may be more

sharply pointed in lateral teeth, whilst a small linguo-distally

projecting boss is present at the posterior of the lingual face of

many lateral teeth. The labial root face is high and flat, and

may be somewhat concave in the central part. There is a clear

but rounded edge between this and the linguo-basal root face,

which is quite flat. The lingual face of the root also forms a

clear but rounded edge with the linguo-basal root face, and is

flat and of a constant height across the width of the tooth.

The central part of the lingual side of the root is rather swol-

len, and extends further lingually than the rest of the tooth.

There is a small but obvious foramen close to the junction of

the lingual and linguo-basal root faces in some teeth, but these

are in the minority. There is a row of large and obvious

foramina just below the base of the labial face of the crown in


Figs 1–23. Squalicorax curvatus (Williston, 1900); all ·4.5. 1–2, P2989.153, parasymphyseal tooth. 1, labial view. 2, lingual view. 3–4,

P2989.154, ? upper anterior tooth. 3, labial view. 4, lingual view. 5–6, P2989.155, ? upper anterior tooth. 5, labial view. 6, lingual

view. 7–8, P2989.156, ? upper anterolateral tooth. 7, labial view. 8, lingual view. 9–10, P2989.157, ? upper anterolateral

tooth showing occlusion damage. 9, labial view. 10, lingual view. 11, P2989.158, ? lower anterior tooth, labial view. 12, P2989.159,

? lower anterior tooth, labial view. 13–14, P2989.160, ? lower anterolateral tooth. 13, labial view. 14, lingual view. 15–16,

P2989.161, ? upper lateral tooth. 15, labial view. 16, lingual view. 17–18, P2989.162, posterolateral tooth. 17, labial view. 18,

lingual view. 19-20, P2989.163, posterolateral tooth. 19, labial view. 20, lingual view. 21–22, P2989.164, posterior tooth. 21, labial

view. 22, lingual view. 23, P2989.165, posterolateral tooth, labial view.


PLATE 7

UNDERWOOD and CUMBAA, Squalicorax

1

23 4

5 6

78

910

11

12 13

14

15 16

18

17

20

19

21 23 22

all teeth, and small and irregular foramina are present across

all faces of the root. The tip of the cusp and ends of the root

lobes are slightly bent labially so that the tooth has an overall

concave labial face in most teeth.

Discussion. The assemblage of teeth assigned to this spe-

cies includes a quite diverse range of morphologies, but

these all fit well within a single reconstructed dentition.

Similarities in the root, serration, proportions and size of

the teeth also suggest the presence of only a single species.

The type material of Squalicorax curvatus Williston, 1900

comprises two teeth, both of which compare well to teeth

described here, and probably represent anterolateral and

posterolateral positions. Subsequent descriptions of Squa-

licorax from the northern part of the Western Interior

Seaway have recognized two morphotypes, and have

either included all in S. falcatus Agassiz, 1843 (e.g. Case

et al. 1990) or have separated them into S. falcatus and

S. curvatus (e.g. Cumbaa et al. 2006; Shimada et al. 2006).

Although some teeth can readily be placed into one of

these morphotypes, others cannot, and Shimada et al.

(2006) comment that the teeth they identify as S. falcatus

appear to grade into S. curvatus and S. sp. (the last prob-

ably representing lower anterior teeth as described here).

It is now recognized that the diversity of anacoracids is

rather higher than was previously appreciated (e.g. Capp-

etta and Case 1999; Siverson et al. 2007), and some

names, especially Squalicorax falcatus, have been used for

a number of different species. The holotype of S. falcatus

(see Siverson et al. 2007) falls outside the morphological

range of the material described here, having a less clearly

defined distal heel, high cusp with smoothly convex ante-

rior edge and probably smaller serrations and more labio-

lingual compression. Although there has been confusion

between S. curvatus and S. baharijensis Stromer, 1927 (e.g.

Welton and Farish 1993; see Siverson et al. 2007), most

teeth of S. curvatus are considerably more erect and have

a shorter cusp, whilst presumed lower teeth are higher

and have a shorter and wider cusp with a more continu-

ously deep lingual neck.

Squalicorax curvatus was taken as the type species for

the genus Praeptychocorax Glickman, 1980, but the genus

is poorly defined and appears to be largely based on the

supposition that it is ancestral to Ptychocorax Glickman

and Istchenko in Glickman, 1980, and is here considered

invalid.

Genus PALAEOANACORAX Glickman and Shvazhaite, 1971

Type species. Palaeoanacorax volgensis Glickman in Glickman

and Shvazhaite, 1971 from the Cenomanian of Russia.

Remarks. The genus Palaeoanacorax was erected by Glick-

man (Glickman and Shavzhaite 1971) for a group of ana-

coracid species defined both on their morphology and

stratigraphical position. Although the definition of a genus

on stratigraphical grounds should be considered invalid,

the group of species, exemplified by Palaeoanacorax

volgensis Glickman, 1971, included into this genus are

morphologically distinct from Squalicorax Whitley, 1939.

Teeth of Palaeoanacorax differ from those of Squalicorax

s.s. in having a lower crown with well-defined cusp, thicker

and lower root which is overhung by the crown labially,

greater degree of heterodonty and serrations that are incip-

ient, irregular or missing altogether. Whilst Glickman

(1971) did not include Squalicorax falcatus and related

forms into Palaeoanacorax, they were included into the

genus by Sokolov (1978) in some parts of a paper that

elsewhere retains them in Squalicorax (of current usage).

It is considered here that Palaeoanacorax is a valid

genus and includes Squalicorax pawpawensis Siverson

et al., 2007, Squalicorax microserratodon Shimada, 2008,

Squalicorax primulus Muller and Diedrich, 1991, Squalico-

rax priscoserratus Siverson et al., 2007 and Palaeoanacorax

volgensis Glickman, 1971, as well as a number of

unnamed species from the Cenomanian (e.g. Siverson

1997), Turonian ⁄ Coniacian (Cappetta and Case 1999),

Santonian and Campanian (Underwood and Ward 2008).

Eoanacorax Glickman, 1971 is probably a separate valid


Fig. 1. Ptychodus rhombodus sp. nov.; ·25; P2989.61, posterior tooth, occlusal view.

Fig. 2. Squalicorax curvatus (Williston, 1900); ·25; P2989.166, parasymphyseal tooth, labial view.

Figs 3–5. Palaeoanacorax aff. pawpawensis (Siverson et al., 2007); all ·25. 3, P2989.175, parasymphyseal tooth, labial view. 4–5,

P2989.176, parasymphyseal tooth. 4, labial view. 5, lingual view.

Figs 6–18. Orectoloboides angulatus sp. nov.; all ·25. 6–8, P2989.177, posterior tooth. 6, labial view. 7, oblique view. 8, lingual view. 9–

12, P2989.178, holotype, anterior tooth. 9, labial view. 10, oblique view. 11, lingual view. 12, occlusal view. 13–15, P2989.179,

anterior tooth. 13, oblique view. 14, labial view. 15, oblique lingual view. 16–18, P2989.180, posterior tooth. 16, labial view. 17,

oblique view. 18, lingual view.

Figs 19–22. Cretorectolobus robustus sp. nov.; ·12.5; P2989.188, holotype, lateral tooth, 18, labial view. 19, occlusal view. 20, lingual

view. 21, oblique view.


PLATE 8

UNDERWOOD and CUMBAA, Canadian sharks

1

2

3 4 5

7

8

9

10

1112 13

14

16

17 18

15

2221

20

19

anacoracid genus containing a number of Albian and

Cenomanian species possessing elongate cusps, a very

reduced distal heel and no serrations.

Palaeoanacorax aff. pawpawensis (Siverson et al., 2007)

Plate 8, figures 3–5; Text-figure 5A–M

?2001b Squalicorax volgensis (Glickman); Cicimurri,

p. 185, fig. 5h.

aff. 2007 Squalicorax pawpawensis (Siverson et al., 2007);

text-fig. 2A, pl. 1, figs 1–26.


P2989.176.

Description. The teeth of this species are small, the largest being

8.5 mm wide. There is considerable monognathic and probably

minor dignathic heterodonty, with teeth possessing more slender

and erect cusps being from the lower jaw. Parasymphyseal teeth

are small, ranging from one to three millimetres high, close to

A BC

DE F

H

G

I

J

K L M

TEXT -F IG . 5 . Palaeoanacorax aff. pawpawensis (Siverson et al., 2007); all ·8. A–B, P2989.167, anterior tooth. A, labial view. B, lingual

view. C–D, P2989.168, lateral tooth. C, labial view. D, lingual view. E–F, P2989.169, lateral tooth. E, labial view. F, lingual view. G,

P2989.170, posterolateral tooth, labial view. H–I, P2989.171, exceptionally gracile anterolateral tooth. H, labial view. I, lingual view. J,

P2989.172, anterior tooth, labial view. K, P2989.173, anterior tooth, labial view. L–M, P2989.174, anterolateral tooth. L, labial view. M,

lingual view.


symmetrical and more than twice as high as wide. The larger

parasymphyseal teeth are similar to other anterior teeth other

than being considerably more laterally compressed and, in some

cases, possessing a heel or incipient cusplet on both anterior and

posterior sides of the teeth. Smaller parasymphyseal teeth com-

prise a conical to slightly lingually curved cusp projecting from

an oval to near spherical root. In these teeth, the cutting edge

may be severely reduced or even absent.

Of the remainder of the teeth, the crown varies from 75 to

200 per cent as wide as high depending on jaw position, with

only extreme anterior teeth being higher than wide. The main

cusp is strongly inclined to the posterior in all but the most

anterior teeth and is followed by a small but clearly defined dis-

tal heel, the latter being between one sixth and one fifth of the

total width of the tooth. The main cusp is inclined to the pos-

terior, weakly in the most anterior teeth, but very strongly, with

the anterior cutting edge being almost horizontal, in posterolat-

eral teeth. The labial face is faintly convex to flat, with a strongly

convex lingual face, neither with any ornamentation. The ante-

rior edge of the main cusp is convex towards the base, becoming

straight or weakly concave higher up. The apex of the cusp typi-

cally forms and angle of 35–60 degrees, being more acutely

pointed in presumed lower teeth. The posterior edge of the cusp

is straight to very faintly convex. In all teeth there is some

degree of overhang of the main cusp over the distal heel. In

more erect anterior teeth, the apex of the main cusp extends as

far to the posterior as the rear edge of the tooth, but this is not

the case with most teeth. The distal heel is very low, with the

upper edge typically sloping downwards from its anterior end,

and evenly convex. A continuous cutting edge extends along the

main cusp and distal heel. True serrations are not seen on any

teeth, but faint crenulations or incipient serrations are present

on the anterior cutting edge of all teeth except some parasym-

physeal teeth and some posterolateral teeth. These crenulations

do not reach either the apex of the cusp or anterior edge of the

cutting edge. The base of the labial face of the crown extends

down over the upper half of the root, which it strongly over-

hangs. The labial base of the crown is gently concave in all teeth,

and is weakly flared towards the posterior end in some teeth.

The lingual base of the crown has a very obvious neck, which is

highest below the main cusp. The roots of all teeth are gently

curved, with a similar depth of the root (in lingual view) present

along much of its length, resulting in a lack of clearly defined

root lobes. The labial root face is low, being higher at the ante-

rior and posterior ends than near the centre. There is a clear but

rounded edge between this and the linguo-basal root face, which

is smoothly convex, and not clearly differentiated from the low

lingual root face. The central part of the lingual side of the root

is rather swollen, and extends further lingually than the rest of

the tooth. The roots of all teeth are heavily vascularized. There

is a row of large and obvious foramina just below the base of

the labial face of the crown in all teeth, and the overhanging

base of the crown may be somewhat indented next to the foram-

ina. Large and irregular foramina are present across the linguo-

basal root face, often joining to form irregular, branching

grooves in the root. Foramina are present on the lingual face of

the root, but these are smaller than elsewhere and present within

faint vertical grooves.

Discussion. These teeth are very abundant and the large

sample size allows the very high degree of heterodonty

shown by this species to be recognized. There are large

numbers of small parasymphyseal teeth recognized within

the collection, suggesting that several files were present on

at least one or possibly both, jaws. This has not been rec-

ognized in other anacoracid taxa (e.g. Shimada 2008).

The smaller parasymphyseal teeth may easily be mistaken

for teeth of co-occurring Cretomanta canadensis Case

et al., 1990, but may be separated from them by, amongst

other things, a less erect cusp and presence of a cutting

edge.

Although very similar to the topotype material of Pal-

aeoanacorax volgensis as figured by Siverson et al. (2007),

the labial basal margin of the crown is gently concave,

and not strongly scalloped. In addition, the majority of

the teeth described here have a more slender cusp and

wider distal heel than figured specimens of Palaeoanaco-

rax volgensis. The same differences separate Palaeoanaco-

rax aff. pawpawensis from the species present in the

Australian Cenomanian (described as Squalicorax volgensis

by Siverson (1996)) and specimens from the Turonian ⁄Coniacian boundary of Texas (described as Squalicorax

volgensis by Cappetta and Case (1999)). Palaeoanacorax

aff. pawpawensis is most similar to P. pawpawensis (Siver-

son et al. 2007) (including specimens figured as P. volgen-

sis by Cappetta and Case (1999) and Welton and Farish

(1993)), but appears to differ in typically possessing a

shorter and more robust cusp and larger but less well-

developed serrations on the majority of teeth, in addition

to having a smaller maximum size. Although it is

probable that Palaeoanacorax aff. pawpawensis and

P. pawpawensis are different species, there is considerable

morphological overlap between populations of both, and

it is at present not possible to clearly differentiate these

taxa. Palaeoanacorax aff. pawpawensis is also very similar

to P. primulus (Muller and Diedrich 1991), and there is a

possibility that they could be conspecific, but the poor

preservational and illustration quality of holotype and

paratype specimens (Siverson et al. 2007) make compari-

sons difficult. Palaeoanacorax aff. pawpawensis teeth differ

from those of the Albian P. priscoserratus (Siverson et al.

2007) and the Coniacian P. microserratodon (Shimada

2008) in the form of serration and root.

Order ORECTOLOBIFORMES Applegate, 1972

INCERTAE FAMILIAE

Genus ORECTOLOBOIDES Cappetta, 1977

Type species. Ginglymostoma parvula Dalinkevicius, 1935 from

the ?Albian of Lithuania.


Orectoloboides angulatus sp. nov.


Derivation of name. After the angular overall appearance of the

teeth.


Material. Three teeth studied (P2989.177; P2989.179–P2989.180).

Diagnosis. Teeth small, under 2 mm in greatest dimen-

sion, showing moderate heterodonty. Tooth crown of

similar width to height. All teeth close to symmetrical,

with a robust and conical main cusp (less than 1.5 times

as high as wide) flanked by a single pair of short and

robust lateral cusplets, with a second pair of incipient

cusplets sometimes being present. A single ridge forming

a sharp-edged keel is present on the labial face, and

extends from half way up the main cusp to the base of a

narrow but very prominent labial boss, sometimes bifur-

cating near the base. Other, shorter, ridges are present

elsewhere on the crown but are always widely spaced and

never join. Lingual crown face strongly convex with a

very well-developed lingual protuberance at the base.

Other than the labial boss, the crown does not strongly

overhang the root. The root is wider and deeper than the

crown, with a very well-developed nutritive groove seen

in all teeth. The distal parts of the root lobes are some-

what recurved labially and have flared bases.

Description. Teeth of this species are small and robust, with an

overall very ‘angular’ appearance. All teeth are a similar height

to width. The main cusp is conical and higher than wide with

the base making up about half of the width of the tooth crown.

This is flanked by a single pair of short and robust lateral cus-

plets, which may have a second pair of incipient cusplets on

their outer margin. The lateral cusplets are about as high as wide

and slightly divergent. A well-developed cutting edge runs from

the outer edge of the tooth crown and over the cusplets, but

does not reach the apex of the main cusp. The labial surface of

the tooth crown extends over the labial face of the tooth for at

least the same distance as the height of the lateral cusplets. A

very prominent labial protuberance is present below the main

cusp. This is roughly parallel sided with a rounded termination,

and is about half of the width of the base of the main cusp. The

labial face of all cusps is weakly convex. A very prominent,

sharp-edged ridge extends from the tip of the labial protuber-

ance to about half way up the main cusp. In one tooth, this

bifurcated into two ridges on the labial protuberance Pl. 8, figs

13–15). Additional, short longitudinal ridges are present on the

more lateral parts of the crown labial face. In the two larger

teeth, they are short and very weak with two or three ridges

being present below the lateral cusplets. On the two smaller

teeth, these ridges are more strongly developed, with up to five

on either side of the tooth. The lingual side of the cusps is

strongly convex, and below the main cusp this becomes

expanded downwards to form a lingual uvula. The uvula pro-

jects lingually to varying degrees, and extends downwards to the

lingual end of the root nutritive groove. Other than at the point

of the labial protuberance, the labial basal edge of the crown

only weakly overhangs the top of the root. There is no crown

overhang of the root lingually, and the basal lingual edge of the

crown has a narrow smooth neck at the junction with the root.

The root is bulky and slightly wider than the crown in all teeth.

The root is very strongly bilobate, with a wide and deep nutri-

tive groove extending for the whole depth of the root. The labial

surface of the root lobes is laterally and labially flared basally,

giving a rounded profile to the lateral edge of the root. The late-

ro-labial face of the root lobes also flares downwards, especially

on either side of the nutritive groove, where it forms a pointed

lingual projection. There is a sharply angled edge of the basal

face of the root all round. The basal face of the root lobes is

smooth and only slightly convex. Other than at least one very

large foramina within the nutritive groove, foramina are few but

quite prominent, with two or three circular to oval foramina on

each latero-labial root face and one to four on each basal root

face.

Remarks. Teeth of Orectoloboides angulatus sp. nov. are

very similar to those of O. parvulus Dalinkevicius, 1935,

but differ in several ways. The cusps of O. parvulus are

higher and more slender, with this being especially evi-

dent in lateral cusplets, where a second pair of clearly

separated cusplets is often present (CJU, pers. obs.). In

addition, teeth of O. parvulus appear to show a greater

degree of heterodonty with the distinctive lateral tooth

morphology (e.g. Cappetta 1977, fig. 2) not being recog-

nized here. Teeth of O. multistriatus Werner, 1989 have a

considerably finer and more densely spaced ornament.

Teeth of O. angulatus sp. nov. are superficially similar to

teeth of some sclerorhynchids, but differ in the presence

of lateral cusplets, a strong ornament and a more arched

and flared root.

Genus CRETORECTOLOBUS Case, 1978

Type species. Cretorectolobus olsoni Case, 1978, from the Campa-

nian of Montana, USA.

Cretorectolobus robustus sp. nov


Derivation of name. From the relatively large and robust teeth

compared to others of the genus.

Holotype and only specimen. P2989.188 (Pl. 8, figs 19–22). This

was collected as part of the Canadian Museum of Nature study

and not from the same sub sample as the rest of the material

described here.


Diagnosis. Near symmetrical tooth with single erect cusp.

Tooth considerably wider than high, with blade-like lat-

eral crown extensions of similar width to root. Lateral

crown extensions of uniform height without cusplets but

noticeably arched to give convex occlusal surface. Occlu-

sal cutting edge of lateral extensions sigmoidal in occlusal

view. Labial protuberance prominent but narrow and par-

allel sided with rounded apex. Uvula tapering and quite

weakly developed. Root low and somewhat extended lin-

gually in region of uvula. Hemiaulacorhize root vasculari-

zation with well-developed small foramina on all faces of

root except labial face.

Description. The single tooth known is from a presumed lateral

position and is 4.4 mm wide. The tooth has a general ‘squati-

noid’ morphology, with an erect cusp at close to right angles

from the flattened and triangular root. The cusp is triangular

and has a height less than one third of the total tooth width

and slightly linguo-posteriorly curved. The cusp is triangular

with a convex labial surface and strong convex lingual surface.

At its base, the cusp merges with lateral blades on both mesial

and distal sides. These blades are of relatively constant height,

but are somewhat curved with a convex occlusal surface with

no incipient cusplets. The distal ends of the lateral blades are

smoothly rounded. There is a well-developed cutting edge

extending for the entire occlusal surface of the crown. When

viewed occlusally, there is a distinct sigmoidal curvature to the

cutting edge on the lateral blades. Below the labial face of the

cusp is a well-developed labial protuberance which extends to

at least the full depth of the root. This is narrower than the

base of the cusp, parallel sided and with a rounded tip. A wide

but shallow uvula is present on the lingual side of the tooth,

extending from the base of the cusp to the lingual edge of the

root. There is no ornament on the crown. Other than around

the labial protuberance, there is no crown overhang of the

root, but the crown-root contact is sharp and well defined.

The root is low and triangular in basal view. The root is about

three times as wide as the labiolingual depth, with a straight

labial face and expanded lingually to the tip of the uvula. The

labial root face is as wide as the crown and slightly flared at

the base. There is a sharp but not angled contact between this

and the basal face, which is broadly concave. The lingual root

face is slopes from the base of the crown to a distinct contact

with the basal face. There is a large foramen near the centre of

the root basal face and another just below the lingual tip of

the root. Small foramina are scattered across all faces of the

root except the labial face.

Remarks. A number of genera have been proposed for

teeth with a general ‘squatinoid’ morphology from the

Cretaceous, with different species being assigned to either

the Orectolobiformes or the Squatiniformes. The tooth

described here is assigned to the former because of the

low and rather robust cusp, high lateral blades and a root

that is only weakly expanded lingually. Cretorectolobus

robustus sp. nov. differs from C. olsoni Case, 1978 from

the Campanian of North America in having a more

robust cusp, no incipient lateral cusplets, a more slender

labial protuberance and more random spread of foramina

over the root. C. gracilis Underwood and Mitchell, 1999

from the British Albian and C. doylei Underwood et al.,

1999 from the British Hauterivian have a far smaller max-

imum size then C. robustus sp. nov. C. gracilis also differs

in having very reduced lateral blades and a higher root,

whilst C. doylei has incipient lateral cusplets and a rela-

tively high root. Teeth of species of the related genus Ced-

erstroemia Siverson, 1995 are more robust overall, with a

flattened and triangular cusp.

Superorder BATOMORPHII Cappetta, 1980b

Order RAJIFORMES Berg, 1940

Family RHINOBATIDAE Muller and Henle, 1838

Genus RHINOBATOS Linck, 1790 s.l.

Type species. Rhinobatos rhinobatos Linnaeus, 1758; extant.

Remarks. The genus Rhinobatos has been used for teeth

and skeletons of a large number of extinct species of rhin-

obatid (e.g. Cappetta 2006). Although many taxa previ-

ously assigned to Rhinobatos have subsequently been

moved to other genera, many fossil species of Rhinobatos

remain, many of which will probably need to be moved

to other genera in the future.

‘Rhinobatos’ cf. incertus Cappetta, 1973

Text-figure 6A–H

1973 Rhinobatos incertus Cappetta, p. 508, figs 26–33.

1973 Rhinobatos sp. Cappetta, p. 508, figs 18–25.

1990 ?Rhinobatos sp. Case et al., p. 1093, figs 12–13.

1993 Rhinobatos sp. Williamson et al., p. 458, fig. 8.

1993 Rhinobatos incertus Cappetta; Welton and Farrish,

p. 132, figs 1–2.

2001a ?Rhinobatos incertus Cappetta; Cicimurri, p. 185,

fig. 5X.

2004 ?Rhinobatos incertus Cappetta; Cicimurri, p. 9,

fig. 5J.

2006 Rhinobatos sp. Shimada et al., p. 19, fig. 11.3–11.4.

2007 Rhinobatos incertus Cappetta; Everhart, p. 230

(pars), fig 6B–D (non A).

Material. Two teeth (P2989.181 and P2989.182).

Description. Both teeth are less than 1 mm across and have low

crowns. The teeth are similar in width to height and have a

crown that is somewhat larger than the root. The labial face of

the crown is weakly convex and rather wider than high, and


somewhat lozenge-shaped, with rounded edges lingually and la-

biobasally and rather sharply angled lateral ends. There is no

defined cusp, but the labial face of the crown is somewhat

expanded above the lingual uvula to form an incipient cusp,

although this is largely removed by wear in one specimen. The

lingual face of the crown is angled at nearly right angles to the

labial face, with an angled contact but without a defined cutting

edge. The central half of the lingual face comprises a well devel-

oped and somewhat bulbous uvula. The uvula is somewhat

tapered basally and extends about twice as far down the root lin-

gual face as the lateral parts of the crown. Lateral uvulae are

poorly developed, and comprise little more than the lingual

crown face separated from the main uvula by a variably well-

developed groove. The crown is unornamented. The crown

strongly overhangs the root on all sides. The root is of a similar

width to the crown and slightly displaced lingually. The root is

A

BC D

E FG H

JI K

L M

S

UT

R

QP

N

O

TEXT -F IG . 6 . A–H. ‘Rhinobatos’ cf. incertus Cappetta, 1973; all ·40. A–D, P2989.181. A, occlusal view. B, lingual view. C, oblique

view. D, basal view. E–H P2989.182. E, occlusal view. F, lingual view. G, oblique view. H, basal view. Figs I–U. Cretomanta canadensis

Case et al., 1990; all ·25. I–J, P2989.183, fused tooth. I, labial view. J, oblique view. K–M, P2989.184. K, labial view. L, lateral view. M,

occlusal view. N–O, P2989.185. N, lateral view. O, labial view. P–R, P2989.186. P, labial view. Q, lateral view. R, occlusal view. S–U,

P2989.187. S, labial view. T, occlusal view. U, lateral view.


strongly bilobate, with a wide and conspicuous nutritive groove.

The linguolateral root faces flare basally from beneath the crown,

and are relatively flat. The root basal faces are flat and slightly

angled laterally. In basal view, each root lobe basal face is trian-

gular, being of similar size in one tooth but rather asymmetrical

in the other, where the nutritive groove is wider. There is at

least one very large foramen within the nutritive groove, along

with one small foramen on each linguolateral root face and sev-

eral on each root lobe basal face.

Discussion. The teeth seen here appear to be the same

taxon as noncuspate teeth figured as Rhinobatos sp. by

Cappetta (1973). This species co-occurs with the cuspate

teeth that include the type material of R. incertus Cappet-

ta (1973), which it resembles in all but form of the occlu-

sal surface. In all instances where cuspate teeth referred

to, or resembling, R. incertus have been recorded, noncus-

pate teeth of the type recorded here are also present; in

addition, where an idea of proportions is recorded

(Cappetta 1973; Shimada et al. 2006), noncuspate teeth

far outnumber cuspate. It is therefore considered here (as

by Welton and Farish 1993 and Everhart 2007) that Rhin-

obatos sp. and R. incertus are conspecific, with the cuspate

morph representing teeth of breeding males.

Despite the poor quality of figures of some specimens

referred to this species (e.g. Case et al. 1990; Cicimurri

2001a, 2004), teeth appear to be widespread within the

Western Interior Seaway, and range from Upper Albian

to at least Coniacian (Everhart 2007). This species does

not, however, appear to be present in Europe or further

afield (e.g. Herman 1977; CJU, pers. obs.).

?BATOMORPHII incertae sedis

Genus CRETOMANTA Case et al., 1990

Type species. Cretomanta canadensis Case et al., 1990 from the basal

Turonian of Saskatchewan (published incorrectly as Coniacian).

Cretomanta canadensis Case et al., 1990

Text-figure 6I–U

1990 Cretomanta canadensis Case et al., p. 1093, fig. 14a–c.

1993 ?Rhincodontidae Welton and Farish, p. 86, figs 1–3.

2001a Cretomanta canadensis Case et al.; Cicimurri, p. 185,

fig. 5S–T.

2004 Cretomanta canadensis Case et al.; Cicimurri, p. 9,

fig. 5O.

2006 Cretomanta canadensis Case et al.; Shimada et al., p.

19, fig. 11.7–11.8.

Material. Forty-seven teeth studied including P2989.183–

P2989.187.

Description. Teeth of this species are up to 1.5 mm high and

are relatively homodont. The single cusp, or in the case of

one specimen, each of two equal sized cusps, comprises about

half of the total height of the tooth and is erect, being either

near vertical (relative to the root basal face) or slightly

inclined labially. The cusp is round in cross-section to slightly

laterally compressed, and lacks any cutting edge. The cusp is

one to 1.5 times as high as deep and strongly curved lin-

gually, with a curvature on the labial edge of 45–70 degrees.

There is a well-developed collar at the base of the cusp that

is somewhat constricted, with the thickest part of the cusp

being close to the centre, tapering to a slender and sharp

point.

The root is rounded and globular. In smaller teeth, it is

near spherical, but in most teeth the root is somewhat

expanded lingually. The labial face of the root is near vertical,

whereas other faces are flat to slightly concave, with the root

widening downwards and lingually to gently convex basal face.

Small foramina are spread across the root, but are concen-

trated on the mid part of the lateral root faces and on the

basal face.

In broken or transparent teeth, it is possible to see a slender,

tubular, pulp cavity running most of the length of the cusp.

Small tubules branch from this and are obvious within the

dentine.

Discussion. The affinity of Cretomanta canadensis is very

uncertain, largely because of the extremely convergent

and conservative morphology of teeth of microphagous

chondrichthyans. The overall morphology of the teeth is

extremely similar to that of the reduced parasymphyseal

teeth of Palaeoanacorax aff. pawpawensis. Teeth of

C. canadensis do, however, differ in having a more erect

and strongly curved cusp, a slightly fusiform labial cusp

profile, the lack of a cutting edge on all teeth, and a nar-

row pulp cavity. The form of vascularization suggests that

a lamniform affinity is not supported (contra Cappetta

2006), but may suggest a batomorph affinity. The pres-

ence of a ‘double’ tooth is similar to those present where

row splitting occurs in the dentition of some batoids (e.g.

Herman et al. 2000, textplate 5), and may further suggest

a batoid affinity. Although the tooth morphology is not

unlike that of some extant planktivorous batoids, it is

likely that this is convergently derived and as such family

level affinities are uncertain. Despite the morphology of

the teeth suggesting planktivory, faint longitudinal

scratches may be present, but it is not certain whether

these are a result of wear against rigid food items or

because of occlusion with teeth on the opposing jaw.

Teeth of similar morphology as the type material of Cre-

tomanta canadensis have been recognized (CJU, pers.

obs.) in rocks ranging in age from Cenomanian to Maas-

trichtian (Noubhani and Cappetta 1997), but it is cur-

rently uncertain whether this comprises several separate

species.


PALAEOECOLOGY

The assemblage recovered from the Bainbridge River

bonebed represents a relatively low diversity assemblage

dominated by pelagic predators. Although an abundance

of lamniforms appears to be a common feature of Creta-

ceous assemblages from the Western Interior Seaway (e.g.

Welton and Farish 1993; Williamson et al. 1993; Cappetta

and Case 1999), the almost complete lack of small necto-

benthic taxa in the Bainbridge River assemblage is excep-

tional. The elasmobranch fauna is associated with a very

rich and diverse assemblage of actinopterygians, with

remains of hesperornithiform birds also being common

(e.g. Cumbaa et al. 2006). Other nonavian reptiles are

relatively rare, with only plesiosaurs being regular finds.

The vast majority of the vertebrates appear to be active

predators, with teeth adapted for either clutching active

prey or, more rarely, cutting larger prey. Durophagous

taxa are relatively uncommon, although several species of

Ptychodus and pycnodonts are present. Teeth of Ptychodus

rarely appear to show wear, and so it is possible that the

main food source is not the same, or as hard shelled, as

that favoured by some Ptychodus species elsewhere. The

abundant remains of small teleosts and possibly teeth of

Cretomanta suggest that planktivores were common. The

extremely low number of teeth of benthic batoids and

orectolobids may be because of occasional transient

individuals. This assemblage therefore represents a very

high nutrient environment with a hostile sea floor.

Some of the species recorded here (Cretoxyrhina dentic-

ulata and Ptychodus ex. gr. decurrens) appear to have a

global distribution, but the majority are more restricted in

their range. Shallower water sites in the northern Western

Interior Seaway share some of the species with the fauna

described here (Case 2001; Cook et al. 2008) but contain

several lamniform and batoid taxa not present here, and

lack the Ptychodus. Comparisons of small tooth taxa are

not possible because of different collecting regimes. Many

of the taxa recorded here are also present (albeit previ-

ously unrecognized) at other sites within the offshore parts

of the northern Western Interior Seaway (e.g. Cappetta

1973; Cicimurri 2001b; Shimada et al. 2006), which also

contain Tethyan faunal elements not recorded at the Bain-

bridge River. The diverse chondrichthyan assemblages

known from the southern Western Interior Seaway in

Texas (e.g. Welton and Farish 1993; Cappetta and Case

1999) have little in common with those from the Bain-

bridge River, with only Squalicorax curvatus and ‘Rhino-

batos’ incertus present within Cenomanian rocks of both

regions but not seen outside the Seaway. This is consistent

with evidence from other vertebrate groups for at least

two distinct faunal provinces in the Western Interior Sea-

way (Nicholls and Russell 1990). In contrast, there are sev-

eral taxa present in Texas that are also present in Egypt

(Werner 1989), indicating a stronger Tethyan link for the

Texas assemblage than for a north-south connection

through the Western Interior Seaway.

The mid Cretaceous distribution of Archaeolamna ex.

gr. kopingensis is strongly indicative of it as a cool water

taxon, being also present in northern Europe (e.g. Biddle

1993; Vullo et al. 2007) and Australia (Siverson 1996;

1997) but absent in Texas. It is therefore likely that a

marine connection between the northern Western Interior

Seaway and Boreal Ocean existed at this time, allowing

direct connection to cool waters elsewhere.

If wide ranging taxa are excluded, there are no species

in common between the Bainbridge River and mid

Cretaceous faunas of northern Europe (e.g. Muller and

Diedrich 1991; Underwood and Mitchell 1999), and com-

mon European taxa appear to be completely lacking in

the Western Interior Seaway. This may suggest that there

was no direct connection in the Cenomanian between the

northern Western interior Seaway and the Proto Atlantic

across what is now Hudson Bay.

Acknowledgements. Support for this research came from the

Canadian Museum of Nature (CMN) and a Discovery Grant to

SLC for student support from the Natural Sciences and

Engineering Research Council of Canada and University of

London Central Research Fund GLRP5 to CJU. The field research

was conducted under Saskatchewan Heritage Palaeontological

Resource Investigation Permit # 06-03P. Harold Bryant and Tim

Tokaryk of the Royal Saskatchewan Museum ensured that the

specimens were properly catalogued. Richard Day (CMN) and

MSc. student Aaron Phillips (Carleton University) provided field

and laboratory assistance, and CMN volunteer Dale Patten helped

sort through the residue from acid preparation of the bonebed.

David Ward greatly assisted with the photography and his

knowledge was invaluable for reconstruction of the lamniform

dentitions. Kenshu Shimada is thanked for his helpful discussions

on WIS sharks. Michal Ginter, Jurgen Kriwet and David Ward

are all thanked for their contributions and comments as reviewers

of the manuscript.

Editor: Marcello Ruta

REFERENCES

A G A S S I Z , L. J. R. 1833–1844. Recherches sur les poissons fos-

siles. Text (5 vols; I., xlix+188 pp., II xii+310 + 366 pp., III

viii+390 pp., IV xvi+296 pp., V xii+122 + 160 pp.) and Atlas

(5 vols; I 10 pl., II., 149 pl., III 83 pl., IV, 61 pl., V, 91 pl.).

Neuchatel.

A P PL E G A T E , S. P. 1972. A revision of the higher taxa of

Orectolobids. Journal of the Marine Biological Association of

India, 14, 743–751.

B E R G , L. S. 1940. Classification of fishes, both recent and fossil.

Transactions of the Institute of Zoology, Academy of Sciences

USSR, 5, 85–517. [In Russian].


—— 1958. System der Rezenten und Fossilen Fischartigen und

Fische. Hochschulbucher fur Biologie, Berlin, 310 pp.

B I D DL E , J.-P. 1993. Les Elasmobranches de l’Albien inferieur

et moyen (Cretace inferieur) de la Marne et de la Haute-

Marne (France) in Elasmobranches et Stratigraphie. Belgian

Geological Survey Professional Paper, 264, 191–240.

B UC K L A N D, W. 1838. On the discovery of fossil fishes in the

Bagshot Sands at Goldworth Hill, 4 miles North of Guildford.

Proceedings of the Geological Society of London, 2, 687–688.

C A DE N A T, J. 1963. Notes d’Ichtyologie ouest-africaine.

XXXIX. – Notes sur les requines de la famille des Carchariidae

et des formes apparentees de L’Atlantique ouest-africaine (avec

la description d’une espece nouvelle: Pseudocarcharias pelagi-

cus, classee dans un sous-genre nouveau). Bulletin de l’Institut

Francais d’Afrique Noire A, 25, 526–543.

C A P PE T T A , H. 1973. Selachians from the Carlile Shale

(Turonian) of South Dakota. Journal of Paleontology, 47, 504–

514.

—— 1977. Selaciens nouveaux de l’Albien superieur de Wissant

(Pas-de-Calais). Geobios, 10, 967–973.

—— 1987 Chondrichthyes II, Mesozoic and Cenozoic Elasmo-

branchii. Handbook of Paleoichthyology. Vol. 3B, Stuttgart, 193

pp.

—— 1980a. Modification du statut generique de quelques

especes de selachiens cretaces et tertiaires. Palaeovertebrata, 10,

29–42.

—— 1980b. Les selaciens du Cretace superieur du Liban 2: Bato-

ides. Palaeontographica, Abteilung A, 168, 149–229.

—— 2006. Elasmobranchii Post-Triadici (Index generum et

specierum). 295–396. In R E I G R A F , W. (ed.). Fossilium Ca-

talogus I: Animalia, Pars 142. Backhuys Publishers, Leiden, 472

pp.

—— and C A S E , G. R. 1975. Selaciens nouveaux du Cretace du

Texas. Geobios, 8, 303–307.

—— —— 1999. Additions aux faunes de selaciens du Cretace du

Texas (Albien superieur–Campanien). Palaeo Ichthyologica, 9,

1–112.

C A S E , G. R. 1978. A new selachian fauna from the Judith River

formation (Campanian) of Montana. Palaeontographica, Abtei-

lung A, 160, 176–205.

—— 1979. Cretaceous selachians from the Peedee Formation

(Late Maestrichtian) of Duplin County, North Carolina.

Brimleyana, 2, 77–89.

—— 2001. A new selachian fauna from the Coleraine Formation

(Upper Cretaceous ⁄ Cenomanian) of Minnesota. Paleaeonto-

graphica Beitrage zur Naturgeschichte der Vorzeit, 261, 103–

112.

—— and CA PP E T TA , H. 2004. Additions to the elasmo-

branch fauna from the Late Cretaceous of New Jersey (Lower

Navesink Formation, Early Maastrichtian). Palaeovertebrata,

33, 1–16.

—— T OK A R Y K , T. T. and BA I R D, D. 1990. Selacians from

the Niobrara Formation of the Upper Cretaceous (Coniacian)

of Carrot River, Saskatchewan, Canada. Canadian Journal of

Earth Sciences, 27, 1084–1094.

C A S I E R, E. 1947. Constitution et evolution de la racine

dentaire des Euselachii. Bulletin du Musee Royal d’Histoire

Naturelle de Belgique, 23, 1–45.

C I C I M UR R I , D. J. 2001a. Cretaceous elasmobranchs of the

Greenhorn Formation (Middle Cenomanian – Middle Turo-

nian), Western South Dakota. National Park Service, Proceed-

ings of the 6th Fossil Resource Conference. Geological Resources

Division Technical Report, 27–43.

—— 2001b. Fossil Selachians from the Belle Fourche Shale (Cre-

taceous, Cenomanian), Black Hills Region of South Dakota

and Wyoming. The Mountain Geologist, 38, 181–192.

—— 2004. Late Cretaceous Chondrichthyans from the Carlile

Shale (Middle Turonian to Early Coniacian) of the Black Hills

Region, South Dakota and Wyoming. The Mountain Geologist,

41, 1–16.

C OM PA GN O , L. J. V. 1977. Phyletic relationships of Living

Sharks and Rays. American Zoologist, 17, 303–322.

—— 2001. FAO Species Catalogue for Fishery Purposes No. 1.

Sharks of the World: An Annotated and Illustrated Catalogue

of Shark Species Known to Date, vol. 2: Bullhead, Mackerel

and Carpet Sharks (Heterodontiformes, Lamniformes and

Orectolobiformes). FAO, Rome, 269 pp.

C OO K , T. D., W I L S O N , M. V. H. and M UR R A Y , A. M.

2008. A middle Cenomanian euselachian assemblage from the

Dunvegan Formation of northwestern Alberta. Canadian Jour-

nal of Earth Sciences, 45, 1185–1197.

—— M UR R A Y , A., W I L S O N , M., T A K E UC H I , G. and

S H I M A DA , K. in press. A partial skeleton of the late Creta-

ceous lamniform shark, Archaeolamna kopingensis, from the

Pierre Shale of western Kansas. Journal of Vertebrate Paleon-

tology.

C OP E , E. D. 1874. Review of the Vertebrata of the Cretaceous

period found west of the Mississippi River. Section I. On the

mutual relationships of the Cretaceous and Tertiary forma-

tions of the west. Section II. List of species of Vertebrata from

the Cretaceous formations of the west. Bulletin of the U.S.

Geological and Geographical Survey of the Territories, 1, 2–48.

C UM BA A , S. L. and BR Y A N T , H. N.. 2001. Stratigraphic

position of a Late Cretaceous (Cenomanian) bonebed, east-

central Saskatchewan. In Summary of Investigations 2001,

Volume 1, Saskatchewan Geological Survey, Saskatchewan

Energy Mines, Miscellaneous Reports, 2001-4.1, 121–124.

—— and TO K A R Y K , T. T. 1999. Recent discoveries of

Cretaceous marine vertebrates on the eastern margins of the

Western Interior Seaway. Saskatchewan Geological Survey,

Summary of Investigations, 1999, 1, 57–63.

—— S C H R OD E R - A DA M S , C., DA Y , R. G. and PH I L -

L I P S , A. J. 2006. Cenomanian bonebed faunas from the

northeastern margin, Western Interior Seaway, Canada. New

Mexico Museum of Natural History and Science Bulletin, 35,

139–155.

D A L I N K E V I C I U S , J. A. 1935. On the fossil fishes of the

Lithuanian Chalk. I. Selachii. Memoires de la Faculte des

Sciences de l’ universite de Vytautas le Grand, 9, 247–305.

D A V I S , J. W. 1890. On the fossil fish of the Cretaceous Forma-

tion of Scandinavia. Scientific Transactions of the Royal Dublin

Society, Series 2, 4, 363–434.

E V E R H A R T , M. J. 2007. New stratigraphic records (Albian to

Campanian) of Rhinobatos sp. (Chondrichthyes, Rajiformes)

from the Cretaceous of Kansas. Transactions of the Kansas

Academy of Science, 110, 225–235.


G L I C K M A N , L. S. 1957. On the systematic significance of

accessory denticles in the teeth of sharks of the families Lam-

nidae and Scapanorhynchidae. Trudy Geologischeskogo Muzeja

‘A. P. Karpinskogo’, Akademia Nauk SSSR, 1, 103–109. [In

Russian].

—— 1958. Rates of evolution in lamnoid sharks. Doklady Aka-

demii Nauk Soyuza Sovetskikh Sotsialisticheskikh Respublik, 123,

568–571. [In Russian].

—— 1964. Sharks of the Palaeogene and their stratigraphic signifi-

cance [In Russian]. Doklady Akademii Nauk Soyuza Sov-

etskikh Sotsialisticheskikh Respublik, Moscow, 228 pp.

—— 1980. Evolution of Cretaceous and Cenozoic lamnoid sharks

[In Russian]. Doklady Akademii Nauk Soyuza Sovetskikh Sots-

ialisticheskikh Respublik, Moscow, 247 pp.

—— and A V E R I A N O V , A. O. 1998. Evolution of the Creta-

ceous Lamnoid sharks of the genus Eostriatolamia. Paleonto-

logical Journal, 32, 376–384.

—— and S H A V Z H A I T E , R. A. 1971. Sharks of the family

anacoracidae from the Cenomanian and Turonian of Lithua-

nia, Pre–Volga Region and Middle Asia. Paleontologia I Stra-

tigrafia Pribaltiki i Belorussii, 3, 185–192. [In Russian].

H A Y , O. P. 1902. Bibliography and catalogue of the fossil ver-

tebrata of North America. Bulletin of the United States Geologi-

cal Survey, 179, 1–868.

H E R M A N , J. 1977. Les selaciens neocretaces et paleocenes de

Belgique et des contrees limitrophes elements d’une biostratig-

raphie intercontinentale. Memoires pour servir a l’explication

des cartes geologiques et minieres de la Belgique, 15, 1–450.

—— H OV E S TA DT - E U LE R, M., H OV E S TA DT , D. C. and

S T E H M A N N , M. 2000. Contributions to the comparative

morphology of teeth and other relevant ichthyodorulites in

living supraspecific taxa of chondrichthyan fishes. Part B:

Batomorphii. No. 4c: Order Rajiformes – Suborder Mylio-

batoidei – Superfamily Dasyatoidea – Family Dasyatididae –

Subfamily Dasyatinae – Genus: Urobatis – Subfamily Plesioba-

tiodea – Family: Plesiobatidae – Genus: Plesiobatis – Super-

family Myliobatidea – Family: Myliobatidae – Subfamily:

Myliobatinae – Genera: Aetobatus, Aetomylaeus, Myliobatis

and Pteromylaeus – Subfamily: Rhinopterinae – Genus: Rhin-

optera – Subfamily: Mobulinae – Genera: Manta and Mobula.

Addendum 1 to 4a: Erratum to genus Pteroplatytrygon. Bulle-

tin de l¢Institut Royal des Sciences Naturelles de Belgique, Biolo-

gie, 70, 5–67.

H UM A N , B. A., O W E N , E. P., CO M PA G N O , L. J. V. and

HA RL E Y , E. H. 2006. Testing morphologically based phylo-

genetic theories within the cartilaginous fishes with molecular

data, with special reference to the catshark family (Chondrich-

thyes; Scyliorhinidae) and the interrelationships within them.

Molecular Phylogenetics and Evolution, 39, 384–391.

H UX L E Y , T. H. 1880. On the application of the laws of evolu-

tion to the arrangement of the Vertebrata, and more particu-

larly of the Mammalia. Proceedings of the Zoological Society of

London, 1880, 649–662.

J A E KE L , O. 1898. Uber Hybodus Agassiz. Sitzungsberichte der

Gesellschaft Naturforschenden Freunde, 89, 135–146.

K R I W E T , J. 2006. Biology and dental morphology of Priscusu-

rus adruptodontus sp. nov. (Chondrichthyes, Lamniformes)

from the Albian (Early Cretaceous) of Peru. Journal of Verte-

brate Paleontology, 26, 538–543.

—— K L U G, S., CA N U DO , J. I. and C U E N CA - B E S C O S ,

G. 2008. A new Early Cretaceous lamniform shark (Chon-

drichthyes, Neoselachii). Zoological Journal of the Linnean Soci-

ety, 154, 278–290.

L A N D E M A I N E , O. 1991. Selaciens nouveaux du Cretace sup-

erieur du sud-ouest de la France. Quelques rapports a la sys-

tematique des Elasmobranches. Societe Amicale des Geologues

Amateurs, 1, 1–45.

L E R I C H E , M. 1929. Les poissons du Cretace marin de la Bel-

gique et du Limbourg hollandais (note preliminaire). Les re-

sultats stratigraphiques de leur etude. Bulletin de la Societe

Belge de Geologie, de Paleontologie et d’Hydrologie, 37, 199–

299.

L I N C K , H. F. 1790. Versuch einer Eintheilung der Fische nach

den Zahnen. Magazin fur das Neueste aus der Physik und Na-

turgeschichte, 6, 28–38.

L I N N A E US , C. 1758. Systema naturae. Tenth edition. Salvi,

Stockholm, 824 pp.

M A I S E Y , J. G. 1987. Cranial anatomy of the Lower Jurassic

Shark Hybodus reticulatus (Chondrichthyes: Elasmobranchii),

with comments on Hybodontid Systematics. American

Museum Novitates, 2878, 1–39.

—— 1989. Hamiltonichthys mapsi, g. & sp. nov. (Chondrich-

thyes; Elasmobranchii), from the Upper Pennsylvanian of

Kansas. American Museum Novitates, 2931, 1–42.

M A UL , G. E. 1955. Five species of rare sharks new for Madeira

including two new to science. Notulae Naturae (Philadelphia),

279, 1–13.

M C N E I L , D. H. and C A L DW E L L, W. G. E. 1981. Creta-

ceous rocks and their Foraminifera in the Manitoba Escarp-

ment. The Geological Association of Canada Special Paper, 21,

1–439.

M U L L E R , A. and DI E DR I C H , C. 1991. Selachier (Pisces,

Chondrichthyes) aus der Cenomanium von Ascheloh am

Teutoburger Wald (Nordrhein-Westfalen, NW-Deutchland).

Geologie und Palaontologie in Westfalen, 20, 5–105.

M U L L E R , J. and H E N L E , J. 1838–41. Systematische beshrei-

bung der plagiostomen. Veit, Berlin, 200 pp.

N I CH O LL S , E. L. and R US S E LL , A. P. 1990. Paleobiogeog-

raphy of the Cretaceous Western Interior Seaway of North

America: the vertebrate evidence. Palaeogeography, Palaeo-

climatology, Palaeoecology, 79, 149–169.

N O UB H A N I , A. and C A P PE T T A , H. 1997. Les Orectolobi-

formes, Carchariniformes, et Myliobatiformes (Elasmobran-

chii, Neoselachii) des Bassins a phosphate du Maroc

(Maastrichtian-Lutetien basal). Palaeo Ichthyologica, 8, 1–327.

O W E N , R. 1846. Lectures on comparative anatomy and Physiol-

ogy of Vertebrate Animals. Part 1. Fishes, London, 51 pp.

P A T TE RS ON , C. 1965. The phylogeny of the Chimaeroids.

Philosophical Transactions of the Royal Society of London, Series

B, No. 757, 249, 101–219.

P HI L L I P S , A. 2008. A Late Cretaceous (Cenomanian) marine

vertebrate-rich bioclastic horizon from the northeastern margin

of the Western Interior Seaway, Canada. MSc. thesis in Earth

Sciences, Carleton University, Ottawa, 237 pp.


R A F I N E S QU E , C. S. 1810. Caratteri di alcuni nuovi generi e

nouvi spedie di animali e piante della Sicilia, con varie osserv-

azione sopra i medesimi. Palermo, 105 pp.

R E E S , J. and U N DE R W O O D, C. J. 2008. Hybodont sharks

of the English Bathonian and Callovian (Middle Jurassic).

Palaeontology, 57, 117–147.

R I S S O , A. 1810. Ichthyologie de Nice, ou histoire naturelle des

poissons du departement des Alpes Maritimes, Paris, 388 pp.

R U S S E L L , D. A. 1988. A check list of North American marine

Cretaceous vertebrates including fresh water fishes. Occasional

Paper of the Tyrrell Museum of Paleontology, 4, 1–58.

—— 1993. Vertebrates in the Cretaceous Western Interior Sea.

In CA L D W E L L , W. G. E. and K A UF F M A N , E. G. (eds).

Evolution of the Western Interior Basin. Geological Association

of Canada Special Paper, 39, 665–680.

S C H R OD E R - A DA M S , C. J., L E C K I E , D. A., CR A I G , J.

and B L OC H , J. 1999. Upper Cretaceous Colorado Group in

the Pasquia Hills, Northeastern Saskatchewan: A multidisci-

plinary study in progress. In Summary of Investigations 1999,

Volume 1, Saskatchewan Geological Survey, Saskatchewan

Energy Mines, Miscellaneous Reports, 1999-4.1, 52–56.

—— CU M B A A , S. L., B L O CH , J., L E CK I E , D. A., C R A I G ,

J., S E I F E L - DE I N , S. A., S I M ON S , D.-J. H. A. E. and

KE N I G , F. 2001. Late Cretaceous (Cenomanian to Campa-

nian) paleoenvironmental history of the Eastern Canadian

margin of the Western Interior Seaway: bonebeds and anoxic

events. Palaeogeography, Palaeoclimatology, Palaeoecology, 170,

261–289.

S C H W I M M E R , D. R., H O OK S , G. E. III and J OH N S O N ,

B. 2002. Revised taxonomy, age, and geographic range of the

large lamniform shark Cretodus semiplicatus. Journal of Verte-

brate Paleontology, 22, 704–707.

S H I M A D A , K. 1997. Dentition of the Late Cretaceous lamni-

form shark, Cretoxyrhina mantelli, from the Niobrara Chalk of

Kansas. Journal of Vertebrate Paleontology, 17, 269–279.

—— 2007. Skeletal and dental anatomy of the lamniform shark

Cretalamna appendiculata, from the Upper Cretaceous Niobr-

ara Chalk of Kansas. Journal of Vertebrate Paleontology, 27,

584–602.

—— 2008. New anacoracid shark from the Upper Cretaceous

Niobrara Chalk of western Kansas, U.S.A. Journal of Vertebrate

Paleontology, 28, 1189–1194.

—— S CH U M A C H E R , B. A., P A R KI N , J. A. and

PA LE RM O, J. M. 2006. Fossil marine vertebrates from the

lowermost Greenhorn Limestone (Upper Cretaceous: Middle

Cenomanian) in southwestern Colorado. Journal of Paleontol-

ogy Memoir, 63, 1–45.

S I V E R S O N , M. 1992. Biology, dental morphology and taxon-

omy of Lamniform sharks from the Campanian of the Kris-

tianstad Basin, Sweden. Palaeontology, 35, 519–554.

—— 1995. Revision of Cretorectolobus (Neoselachii) and descrip-

tion of Cederstroemia n. gen., a Cretaceous carpet shark

(Orectolobiformes) with a cutting dentition. Journal of Paleon-

tology, 69, 974–979.

—— 1996. Lamniform sharks of the mid)Cretaceous Alinga For-

mation and Beedagong Claystone, Western Australia. Palaeon-

tology, 39, 813–849.

—— 1997. Sharks from the mid)Cretaceous Gearle Siltstone,

Southern Carnarvon Basin, Western Australia. Journal of

Vertebrate Paleontology, 17, 453–465.

—— 1999. Lamniform sharks of the Mid Cretaceous Alinga For-

mation and Beedagong Claystone, Western Australia. Palaeon-

tology, 39, 813–849.

—— and L I N D G R E N , J. 2005. Late Cretaceous sharks Creto-

xyrhina and Cardabiodon from Montana, USA. Acta Palaeon-

tologica Polonica, 50, 301–314.

—— —— and K E L LY , L. S. 2007. Anacoracid sharks from the

Albian (Lower Cretaceous) Pawpaw shale of Texas. Palaeontol-

ogy, 50, 939–950.

S O K OL O V , M. 1965. Teeth evolution of some genera of

Cretaceous sharks and reconstruction of their dentition.

Moskovkoe Obshchestvo Ispytatelie Prirody, Biulleten. Otodel

Geologicheskii, 40, 133–134.

—— 1978. Requins comme fossils-guides pour la zonation et la

subdivision descouches cretacees de Tourousk. Niedra.

Moscou, 61, 1–60. [In Russian].

S T R O M E R , E. 1927. Ergebnisse der Forschungsreisen Prof. E.

Stromers in den Wusten Agyptens. II. Wirbeltier-Reste der

Baharije-Stufe (unterstes Cenoman). 9: Die Plagiostomen, mit

einem Anhang uber kano- und mesozoische Ruckenflossensta-

cheln von Elasmobranchiern. Abhandlungen der Bayerischen

Akademie der Wissenschaften Mathematisch-naturwissenschaftli-

che Abteilung, 31, 1–64.

T H UR M ON D , J. T. 1971. Cartilaginous fishes of the Trinity

Group and related rocks (Lower Cretaceous) of North Central

Texas. Southeastern Geology, 13, 207–227.

U N DE R W O O D, C. J. and M I T C HE L L , S. H. 1999. Albian

and Cenomanian selachian assemblages from North East Eng-

land. Special Papers in Palaeontology, 60, 9–59.

—— and W A R D, D. 2008. Sharks of the Order Carcharhinifor-

mes from the British Coniacian, Santonian and Campanian

(Upper Cretaceous). Palaeontology, 51, 509–536.

—— M I T C H E L L, S. H. and V E L T K A M P , C. J. 1999. Shark

and ray teeth from the Hauterivian (Lower Cretaceous) of

north-east England. Palaeontology, 42, 287–302.

V U L L O, R., CA P PE TT A , H. and N E R A U D E A U , D.

2007. New sharks and rays from the Cenomanian and Turo-

nian of Charentes, France. Acta Palaeontologica Polonica, 52,

99–116.

W E L T O N , B. J. and FA R I S H , R. F., 1993. The Collector’s

Guide to Fossil Sharks and Rays from the Cretaceous of Texas.

Before Time, Texas, 203 pp.

W E R N E R, C. 1989. Die Elasmobranchier-Fauna des Gebel Dist

Member der Bahariya Formation (Obercenoman) der Oase

Bahariya, Agypten. Paleo Ichthyologica, 5, 1–112.

W H I TL E Y , G. P. 1939. Taxonomic notes on sharks and rays.

The Australian Zoologist, 9, 227–262.

W I L L I A M S ON , T. E., KI R KL A N D , J. I. and LU C A S , S. G.

1993. Selachians from the Greenhorn Cyclothem (‘Middle’

Cretaceous: Cenomanian–Turonian), Black Mesa, Arizona,

and the paleogeographic distribution of Late Cretaceous sela-

chians. Journal of Paleontology, 67, 447–474.

W I L L I S T O N , S. W. 1900. Cretaceous fishes, selachians and

ptychodonts. University Geological Survey, Kansas, 6, 237–256.


W O O DW A R D , A. S. 1912. The fishes of the English chalk.

Part 7. Monograph of the Palaeontolographical Society, 65, 225–

264.

Z A N G E R L , R. 1979. New Chondrichthyes from the Mazon

Creek Fauna (Pennsylvanian) of Illinois. 449–500. In N I T E -

CK I , M. H. (ed.). Mazon Creek Fossils. Academy Press, New

York, 581 pp.

—— 1981. Chondrichthyes I – Paleozoic Elasmobranchii. Hand-

book of Paleoichthyology, Vol. 3A, Stuttgart, 115 pp.

NOTE ADDED IN PROOF

Recent description of an articulated skeleton and dentition of Archaeolamna (Cook et al. in press) has some implications

for the dentition of this genus. In most respects the articulated dentition agrees with the dental reconstruction as given

here. Despite this, the articulated specimen demonstrates that the second and third upper anterior teeth as interpreted

here are reversed, a situation superficially more similar to that in extant lamnids than Carcharias. The articulated speci-

men also shows no upper intermediate tooth or other teeth resembling those interpreted here as being in that position.

It is therefore probable that, despite the relative frequency of upper intermediate teeth in the assemblage described here,

some individuals or populations of Archaeolamna lacked teeth in this position.


chondrichthyans from a cenomanian (late cretaceous) bonebed, saskatchewan, canada: canadian...

Documents