lower palaeozoic stratigraphy and palaeontology, karadere ...recorded in the istanbul area...

Geo!. Mag. 137 (5). 2000. pp. 555-582. Primed in the United Kingdom © 2000 Cambridge University Press 555

Lower Palaeozoic stratigraphy and palaeontology, Karadere-Zirze area, Pontus Mountains, northern Turkey

W. T. D E A N * , O. M O N O D f, R . B. R IC K A R D S J , O S M A N D E M IR § & P. B U L T Y N C K t

*Department of Earth Sciences, University of Wales, Cardiff CF1 3YE, UK; and Department of Geology, National M useum of Wales, Cathays Park, Cardiff CF1 3NP, UK

fLaboratoire de Géologie Structurale, UM R-CNRS 6530, Université d ’Orléans, B.P.6759,45067 Orléans Cedex 2, France {Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK

§Turkish Petroleum Corporation, 06520 Ankara, Turkey ^Département de Paléontologie, Institut royal des Sciences naturelles de Belgique, Rue Vautier 29, B-1040 Brussels, Belgium

Abstract - Lower Palaeozoic rocks in the Karadere-Zirze area, east of Safranbolu (Pontides, northern Turkey), range from Early Ordovician to Silurian. Overlying the probably Tremadoc Bakacak Formation are Aydos Formation quartzites, followed conformably by the Karadere Formation, dated as Early Arenig to Early Llanvirn by means of graptolites which are assigned to seventeen genera and include three new forms: Eoglyptogr aptus bouceki, Prolasiograptus haplus praecursor and Undulograptus? miii. Late Arenig trilobites from the Karadere Formation include Bergamia, Cyclopyge, Dionidelkfí, Leioshumardia and Seleneceme. In the Limestone Member of the overlying Ketencikdere Formation, uncommon trilobites suggest only a mid- to late Ordovician age, but conodonts with Colour Alteration Index 5-6 indicate the Amorphognathus tvaerensis Biozone (early Caradoc). Macrofossils are rare in the Siltstone Member, but conodonts from the middle of the unit suggest the highest subzone of the A. tvaerensis Biozone; the youngest visible strata are, on acritarch evidence, at least as high as Caradoc, but the Ashgill is not confirmed and the contact with overlying Silurian rocks is unexposed. The Findikli Formation comprises: a Lower Member, black argillites with Llandovery graptolites and acritarchs; and an Upper Member, grey shales with late Wenlock graptolites, overlain unconformably by Devonian rocks. The succession differs significantly from contemporaneous deposits in southern Turkey and its affinities lie with western Europe, including the Welsh Basin.

(Received 31 August 1999: accepted20 June 2000)

Although the presence of Upper Palaeozoic rocks in northern Turkey (Pontides s. 1.) was recognized in the middle of the nineteenth century, as a result of the discovery of the Zonguldak coalfield (Fig. 1), the identification of older formations has proved more elusive. This is due, essentially, to both the scarcity of outcrops and the predominantly unfossiliferous facies (red sandstones and conglomerates) found in the older successions of the western Pontides. Elowever, several scattered localities with marine fossils have been recorded in the Istanbul area (Yalçinlar, 1955; Sayar, 1964), and a comprehensive review of Palaeozoic formations in the Istanbul region was published by Haas (1968). In contrast to the well-documented, uniformly Gondwanan affinities of the Lower Palaeozoic successions so widely distributed in southern Turkey (Taurides and Border Folds), little is known concerning the possible relationships of Lower Palaeozoic formations in northern Turkey. Nevertheless, several attempts have been made to attribute a European origin to the so-called ‘Palaeozoic of Istanbul’ (Fig. 1) on the basis of global tectonics and the Eurasiatic affinities of the Upper Palaeozoic formations and faunas

1. Introduction (WTD, OM, OD) (Sengör & Yilmaz, 1981; Okay, §engör & Görür, 1994; Görür et al. 1997). The present project provides an opportunity to analyse, and to compare in detail with the Gondwana platforms, a reasonably well-exposed Lower Palaeozoic succession that was discovered by Arpat et al. (1978) in the central Pontides (Karadere- Zirze area), about 350 km east of Istanbul. In a report documenting Devonian conodonts from the same section, Harndi (1975) noted briefly an underlying lithological succcession, 1200 m thick, containing Cambrian, Ordovician and Silurian marine strata (Fig. 2), but his description is difficult to interpret (Dean, 1980, p. 19). Boztug(1992) assumed the same sequence to be continuous from Precambrian to Devonian and proposed a generalized list of formations (Fig. 2). For several years the Turkish Petroleum Corporation (T.P.A.O.) has been engaged in systematic re-mapping of the Pontides, with Osman Dernir responsible for the Karadere area. The present data and samples result from Demir’s joint fieldwork with Dean, M onod and the late Francine M artin in 1991 and 1992, undertaken with the logistical support of T.P.A.O. Preliminary results were summarized by Dean et al. (1997) and the succession of rock units described below (Fig. 2, columns 4 and 5) was established.

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5 5 6 W. T . D E A N A N D O T H E R S

Istranca _ massif '

Zonguldak'NORTH ANATOLIAN'/////¿ A Í J Í T . ' / / / / /

SafranboluISTANBUL

S A K A R Y AANKARA:

50 100km

MEDITERRANEAN SEA

THRACEBASIN

_ \ BLACK \ ^ S E A

i A #zirze| ^ -------— 5 J 1 1 . p o n t i d e s

200km

Figure 1. Outline map of part of the Pontides, northern Turkey, showing most im portant place-names cited in the text, especially Zirze. Palaeozoic outcrops are in black. Principal structural subdivisions, with names in large capitals, follow Okay (1986) and Okay, Çengôr & G örür (1994). Inset map shows location of described area within Turkey.

SYSTEM Hamdi (1975) Boztug (1992)THIS PAPER

Formation & Member System & Series

DEVONIAN

SILURIAN

Limestone and white quartzite

Black shale

Dolomite

Black shale

ORDOVICIAN

Quartzite

Shale(probably

LowerOrdovician)

Siltstone

Kureihadit Fm. Eskibaglar Fm. DEVONIAN (part)

CAMBRIAN

PRE-CAMBRIAN

QuartziteConglomerate

Schist Granite

Zirze Fm. (2,000m)

Dotla Fm. (1,000m)

Yayla Dere Fm. (300m)

Doruk Yayla Fm.

FindikliFm.

Upper Mbr. 94m< not seen

Lower Mbr. 135m

Wenlock

Llandovery

Ketencik- dere Fm.

Siltstone Mbr. 390m

LstMbr. 100m

Karadere Fm. 400m

Caradoc? or younger

Caradoc — ? break — Lower Llanvirn

IArenig

Ay dos Fm. 510m Arenig?

BakacakFm. 340m probablyTremadoc

Gneiss, amphibolite (age unknown)

Figure 2. Lower Palaeozoic succession in the Karadere-Zirze-Yukarikarabüzey area, compared with previous interpretations. Not to scale.

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Lower Palaeozoic biostratigraphy, Pont us Mountains 5 5 7

2. Lithostratigraphic terms (WTD, OM, OD)

Precise correlations with the stratotypes of units employed in the present account are not demonstrated here, but formation names are used as far as possible on the basis of lithofacies and age data published for the type area. The Lower Palaeozoic succession includes only Ordovician and Silurian rocks and was examined, in ascending order southwards along the gorge of the Karadere River, where the basal beds rest unconformably on undated gneiss about 2.5 km north of the hamlet of Acemler (Figs 3, 4), and along the track from Zirze to Yukarikarabiizey, particularly in the valleys of Ketencik Dere and Akçayazi Dere. The units comprise, in ascending order: Bakacak Formation, Aydos Formation, Karadere Formation, Ketencikedere Formation (divided into successive Limestone and Siltstone members), all of which are of Ordovician age; and the Findikli Formation (divided into Lower and Upper members), of Silurian age and followed unconformably (Hamdi, 1975) by Devonian quartzite and limestone, the Eskibaglar Formation. The terms were reviewed briefly by Dean et al. (1997), and the present account provides additional data and maps, together with sections showing details of fossiliferous levels and sample numbers in most formations. Authors of species are given in the text only if they are not included in notes for Ordovician graptolites and trilobites later in the paper.

3. Ordovician rocks (WTD, OM, RBR, PB, OD)

3.a. Bakacak Formation

The unit, about 340 m (est.) thick at the Karadere gorge (Fig. 3), begins with grey-green sandstones which yielded, at a level (OFB-l) 10.6 m above the unconformable base, a few small inarticulate brachiopods, the only macrofossils yet found in the formation. Levels 0.5 m, 10 m and 13 m (SAF-41, SAF-1, SAF-2) above the base (Martin in Dean et al. 1997) yielded numerous, very poorly preserved acritarchs (Cymatiogalea sp.) and diacrodians (including Actinotodissus cf. A. achrasi Martin, 1973, Acanthodiacrodium cf. A. ubui Martin, 1969, and Goniosphaeridium cf. G. uncinatum (Downie) Kjellström, 1971. The probable age is Tremadoc Series, based on the absence of acritarch taxa restricted to the Upper Cambrian and the Arenig-Llanvirn’. The grey- green sandstones grade upwards into dark, red-brown sandstones which are also assigned tentatively to the Tremadoc, though no fossils were found and a palyno- logical sample (SAF-3) from 12 m below the top of the formation proved barren (F Martin, pers. comm.).

3.b. Aydos Formation

The base marks a sharp change to yellow-weathering, thickly and often massively bedded, light-grey to white quartzites, 510 m (est.) thick. The rocks crop out along

the Karadere gorge and extend eastwards, where they form a ridge northeast of Zirze (Figs 3, 5) and are exposed near the unmade road east of that village. No macrofossils were found and the unpromising lithol- ogy discouraged systematic sampling for microfossils. The tentative Trema doc/? Arenig assignment is based on the age of underlying and overlying strata, but the gradational contact with the succeeding Karadere Formation and the interfingering of thick quartzitic sandstone beds in the lower half of that unit suggest that Arenig may be more appropriate.

3.C. Karadere Formation

East of Zirze (Fig. 5) the reference section for the unit in this area lies south of the feature formed by quartzites of the Aydos Formation. The section begins (Dean et al. 1997) at a point 0.4 km east of the village, and the formation base is drawn at the top of the last massive bed of Aydos quarzite in the side of the forestry road leading south to Yukarikarabiizey. Quartzite beds with sharply defined upper surface become progressively less well developed, and interbeds of regressively weathering mudstone and shale more dominant, eventually constituting about three-quarters of the total estimated thickness of 400 m. When fresh the mudstones are black and pyritous, as in the section at the foot of the Karadere gorge, but they are mostly deeply weathered to light-beige or pink rottenstone in forestry roads cut through the cover of Recent superficial deposits that blankets much of the area.

Most of the succession is barren of macrofossils but graptolites may be locally numerous, sometimes preserved in relief on isolated bedding-planes. Trilobites were found in only a limited, medial part (2 m est.) of the succession, where specimens occur usually as dorsally compressed internal and external moulds, and a few poorly preserved gastropods and shelly fragments were found in thin, silty layers. The geographic position of numbered localities is shown in Figures 3 and 5, and their stratigraphie levels in Figure 6. Genera and species of graptolites are listed in Figure 13; the oldest, from the Karadere gorge (FOB-5) and east of Zirze (OFB-3), indicate an early Arenig age which extends as high as FOB-8/OFB-8 (one level), also east of Zirze. Succeeding levels (FOB-12/OFB-9, FOB-13, FOB-14, OFB-10 in ascending order) contain a graptolite assemblage that is essentially transitional between those of the lower Arenig and the Llanvim, and is assigned here to the upper Arenig. Additional support for the latter is provided by the trilobites, which have much in common with those described from the upper Arenig of south Wales, on the southern margin of the Welsh Basin. Uncommon specimens found southeast of Zirze included: agnostid genus and species undetermined (FOB-12), Leioshumardia sp. nov. (FOB-12/OFB-9, 7FOB-13), DionidellcP. sp. (FOB-12), Bergamia cf.

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5 5 8 W. T. D E A N A N D O T H E R S

U T T T ] ~ T 7 ^ r r T ~ T TSA F 1/2

_ X FOB 5

OFB 2 « - FOB Bulamur

41 20

Dinek

^CEMLER

Kapi T epeà

: 1296 m

m m m M

1221 m i

Ayikayasi Tepë:N eogene &

Recent sedim ents

ZIRZETertiary sedim ents {incl. E ocene Ist.) FOB 1 5 / O FB 11

Eskibaglar Fm (Devonian)

ß(®B 25-26

Findikli Fm. (lower & middle Silurian)

FO B 33 FO B 34

Ketencikdere Fm. (upper Ordovician)

Karadere Fm. (lower Ordovician)

FO B 3 5 -3 8 \ \ f O FB 2 0 -22

/ /

" . FO B 18

S A F 16

Aydos Fm.(lower Ordovician) SA F 33 /4 8

FOB 3 9 S A F 35Bakacak Fm.

(lower Ordovician)

G neissic basem ent

FO B 40 SA F 3 6 to o

u ° o ° Mercimeklik T epe

□Fossiliferous locality

( X ) _ ( j |) Section

o 1 Km

FOB 19OB 41

YUKARIKARABUZEY

Figure 3. Geological map of the Karadere-Zirze area, modified from the Turkish Petroleum Corporation’s map by O. Demir (iii Dean eta!. 1997), showing fossil localities discussed in the text. For cross-section along line A-B, see Figure 4.

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Lower Palaeozoic biostratigraphy, Pont us Mountains

CROSS SECTION SOUTH OF ZIRZE

5 5 9

B akacak Fm.(prob. Tremadoc)

G neiss, amphibolile (pre-Ordovician)

Karadere Fm.(Arenig - lower Uanvim)

Aydos Fm." (? Trem adoc - Arenig)

□ Fmdikli Fm. (lower and middle Silurian )

Ketencikdere Fm. (upper Ordovician)

III 111 E ocene lim estone

T] Devonian quartzite (Eskibaglar Fm.)

1500m

1000 m -

Kilçikhçal Sirt

J

ZIRZE VILLAGE

G ôkceler Sirt

Ketencik Dere

YUKARIKARABÜZEYVILLAGE

Merdmeklik T epe Akçayazi

Dere

Figure 4. N orth-south cross-section (A-B) of the Zirze area. See Figure 3 for map showing line of cross-section, stratigraphie key, and place-names. Neogene sediments cap the hill at Mercimeklik Tepe.

Vu»« i»««II -MrtMl. rW'VU _

Figure 5. Map showing fossil localities in the Karadere Formation and the Limestone Member parastratotype of the Ketencikdere Formation in the area east and southeast of Zirze. For key, see Figure 3. FOB-4 and sample numbers adjacent to FOB-14 represent levels too closely spaced to be shown individually.

rushi oni (F OB-12/OFB-9, FOB-13, FOB-14), Cyclopyge sp. (FOB-12), and Selenecerne acuticaudata (FOB-11, FOB-12,7FOB-13).

A gap in exposure of about 10 m (est.) begins about 3.5 m above OFB-10, which in turn lies 8 m above the trilobite-bearing strata, and succeeding beds are next seen in the side of the now dilapidated forest track that runs along the southeast side of Ketencik Dere (Figs 3, 5). Exposures are only intermittent, but four levels (FOB-30, FOB-31, FOB-33, FOB-34) yielded graptolites (Fig. 13), all indicative of the Llanvirn and including the biozonal species D. (Didymograptus) artus Elies & Wood, 1901. Equivalent strata are unexposed

along most of the eastern branch of the forestry track about 700 m east-southeast of Zirze, but one level (FOB-15/ OFB-11), just below a 3.5 m unit of grey limestone at the base of the overlying Ketencikdere Formation, yielded Llanvirn graptolites, including D. (Didymograptus) spinulosus Pemer, 1895 and D. (D.) pseudogeminus Boucek, 1973, which correspond to those from the highest part of the Karadere Formation at Ketencik Dere (see Figs 3, 5,13).

3.d. Ketencikdere Formation

3.d.l. Limestone Member

This member is exposed at two sections (Figs 3, 5): (a) the stratotype, 1.25 km south-southwest of Zirze, beside the track that runs south along the east side of Ketencik Dere valley; and (b) the parastratotype, in the floor and sides of the forestry track at the north end of Akçayazi Dere and 1 km southeast of Zirze. No exposures were found in the intervening and adjacent areas, which are obscured by Recent superficial deposits. The two sections differ in detail and it was not possible to equate individual limestone beds. The stratotype, well exposed at the southward bend in Ketencik Dere (Fig. 3), contains a much larger component of limestone, both medium and thickly bedded, with a significant proportion of mudstone in only the lowest and highest parts. The section begins with a 13.7 m unit of medium bedded limestones and mudstone interbeds; sampling of the lowest limestones for conodonts and the underlying mudstone for acritarchs proved fruitless. An estimated 94 m of steeply dipping, locally folded and faulted strata range from light-grey grainstone-packstone and coarse, thickly bedded cal- carenite to thinly bedded, black micrite. Macrofossil debris was locally common, but identifiable specimens

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were rare and conodonts provided the best evidence of age. The macrofossils include: brachiopod genus and species undetermined (OFB-20, OFB-21, OFB-22, FOB-35); and the trilobites Ampvx sp. (FOB-35, 7FOB-38), raphiophorid? undetermined (FOB-35), Remopleurellcft sp. (FOB-36), undetermined illaenid? fragments (FOB-36) and an undetermined odonto- pleurid? segment (FOB-38). Ampvx is geographically widespread with a long stratigraphie range, from Arenig to Ashgill Series; Rernopleurella was based on a species from the late Caradoc of the Welsh Basin and is best documented (Nikolaisen, 1982) from the Caradoc and Ashgill of Europe and Baltica, but has not been reported from the Mediterranean region.

Three samples from the Limestone Member produced a low-diversity conodont fauna which includes, in addition to the dominant coniform species, representatives of Amorphognathus Branson & Mehl, 1933. Most specimens are black, with CAI (Colour Alteration Index) 5, but a few simple cones and the denticle extremities of some ramiform elements are grey, indicating transition to CAI 6. Determinations are by P. Bultynck.

Two levels at Ketencik Dere, OFB-22 and SAF-47 (Figs 7, 8), yielded conodonts. The former contained Amorphognathus tvaerensis Bergström, 1962, eponymous species of the biozone established by Bergström (1971, p. 98) and said by him to correspond approximately to the lower part of the Caradoc Series. Conodont data from the Welsh Basin and the Welsh Borderland (Bergström, Rhodes & Lindström, 1987; Savage & Bassett, 1985) indicate that the base of the biozone is situated, questionably, in the middle of the previously termed Upper Llandeilo, and the top is within the Soudleyan Substage of the Caradoc (Fortey et al. 1995). In terms of the standard graptolite succession, the A. tvaerensis Biozone is coeval with the upper part of the Nemagraptus gracilis Biozone and the lower part of the Diplograptus multidens Biozone. Fragmentary conodonts from SAF-47, slightly lower in the Limestone Member (Figs 7, 8), are identified as Amorphognathus cf. tvaerensis and indicate a similar age to those from OFB-22.

The rocks of the parastratotype crop out in the floor and margins of the forestry track near the northern extremity of Akçayazi Dere, 1 km southeast of Zirze (Figs 3, 5, 8), where the southerly dip varies from 57° at the north end to 40° at the south end. They consist mainly of regressively weathering silty mudstones, with occasional limestone horizons which form ridges that may be traced east-west for at least a few metres. The following, ascending informal sequence was measured: (i) 2.8 m unit, composed of 15 cm sandy limestone, 1.65 m silty shale, and l m medium bedded sandy limestone; (ii) 24.5 m unit of silty mudstone with occasional beds of grey micritic limestone up to 20 cm thick, including sample OFB-25, 2.5 m below the top; (iii) 18 m unit of silty mudstone with a 50 cm

1200 -

O FB 25

1100- FO B33

OFB 10 FOB 14 FOB 13 FOB I2/ÛFB9 FOB 4/FOB 11

N o fo ss ils recorded

400—

SAF 33 0 0 -

SA F 2 SAF I SAF 41

OFB 1

m 0G n eiss, am phibolitc

U ndated

Figure 6. Stratigraphie section showing relative position of fossil localities in the Bakacak, Karadere and lowest Ketencikdere formations in the Karadere (left column) and Zirze-Ketencik Dere (right column) areas.

bed of grey limestone at the base; (iv) 37 m unit, mainly silty mudstone with a 2.7 m composite unit of thinly bedded limestone and shale forming a feature at the base; (v) 14 m composite limestone/shale unit, with a 1 m group of thinly bedded limestones at the base and a conspicuous feature at the top, formed by a 5.4 m group of medium bedded limestones (OFB-26 in topmost bed).

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stale

-G m

¡ {Incom pletely exposed ¡ shale with thin beds ¡ lim estone)

. OFB-22 . FOB 38

FOB-37 . FOB-36 FOB-35

■ SAF-47 OFB-20

• OFB-21

Shale with m edium bedded lim estone

Thinly & m edium bedded lim estone with shale interbeds

Vertical shale passing to thickly & m edium bedded lim estone with shale interbeds

T hickly & m edium bedded lim estone with shale interbeds

M edium Sl thickly bedded lim estone

Shale & thinly bedded lim estone

Shale & m edium bedded lim estone

U

oQ

<«

<Ó

8 , FOB-34

(End o f track exposure)

zc¿t—t

> z < I—I- I

Figure 7. Fossil localities in the Limestone Member of the Ketencikdere Formation at the stratotype in the east bank of Ketencik Dere, 1.25 km south-southwest of Zirze (see Fig. 3 ).

An unidentified trilobite pygidium (Fig. 14t) from OFB-25 and an unfigured fragment of an unidentified cranidium from OFB-26, neither of stratigraphie value, were the only recognizable macrofossils found. OFB-26 also yielded conodonts, Amorphognathus aff. tvaerensis, the identification of which is based on a fragmentary Pa element and Pb elements.

3.d.2. Siltstone Member

The unit was examined at two sections, the more continuous and better exposed of which, in Ketencik Dere,

Figure 8. Relative positions of fossil localities in the Ketencikdere Formation at Ketencik Dere (left column, stratotype) and Akçayazi Dere (right column, parastratotype), and in the Findikli Formation north of Yukarikarabiizey (see Fig. 3).

between 2.5 km and 4.5 km south of Zirze (Figs 3, 8) was chosen as stratotype (Dean et al. 1997); the parastratotype extends from 0.5 to 1 km further east, in and beside the small valley of Akçayazi Dere, where exposure is obscured by Recent deposits. The base of the member was drawn arbitrarily above the highest observed carbonate bed of the Limestone Member at the stratotype, and above the 5.4 m unit of grey, medium bedded limestone at the top of that member at the north end of Akçayazi Dere. Most of the succession is made up of monotonous, poorly bedded, dark grey-green siltstone or silty mudstone in which macrofossils are rare, mostly comprising fragmentary, very small strophomenid brachiopods, together with some

ESKIBAGLAR Fm.

100 m

FO B 15

D E V O N IA N

N O T SE EN

S A F 3 6FO B 4 0

FO B 3 9 S A F 35

S A F 4 8 S A F 33

S A F 16

FO B 18

FOB 43

FO B 16 O FB 2 6

O FB 25

O FB 22 FO B 38 FO B 37 FO B 3 6 FO B 35 S A F 47O FB 20

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pelmatozoan debris; at one locality (FOB-16) near the north end of Akçayazi Dere, two cranidia of the long- ranging (Arenig to Ashgill) Ordovician trilobite genus Prionoclieilus (Fig. 14x) were recovered. The general absence of limestone is striking, with the exception of one conspicuous horizon, comprising 6.5 m of thickly bedded, micritic grey limestone which dips south at 18° and is exposed in the east side of Akçayazi Dere, 1.8 km south-southeast of Zirze (Fig. 3). No macrofossils were found, but conodonts (FOB-18) determined by Bultynck include one posteriorly heeled, rastrate element which agrees with the multi-element definition of the genus Pseudobelodina Sweet, 1979, known especially (Sweet, 1979, 1981) in N orth American successions said to range from Blackriveran, a term now abandoned (Leslie & Bergström, 1995) but equivalent to early Caradoc, through Richmondian (middle to late Ashgill). Three Pb elements and one fragmentary Pa element are tentatively assigned to Baltoniodus alobatus Bergström, 1971, index species for the uppermost of the three sub-biozones of the Amorphognathus tvaerensis Biozone; according to Bergström (1971) this sub-biozone occurs ‘somewhat above the middle of the Diplograptus multidens graptolite zone’, which would place it within an interval covering the Harnagian and Soudleyan substages of the Caradoc in the Welsh basin. An apparently corresponding limestone in Ketencik Dere yielded no macrofossils or microfossils. On the basis of acritarchs, no age distinction could be made between the Limestone and Siltstone members of the Ketencikdere Formation. Taxa in the highest exposed part of the Siltstone Member at Ketencik Dere (Fig. 3, SAF-33, SAF-48) included (Martin in Dean et al. 1997) Diexallophasis remota, Piliferosphaera cf. P. rustica and Vulcanisphaera sp.; D. remota (including cf.), though at least Caradoc, is of imprecise age. No certain evidence of Ashgill strata was found.

4. Silurian rocks (WTD, OM, RBR, OD)

Argillaceous sediments of the Findikli Formation form a large outcrop about 1.25 km wide that extends east-west immediately north of Yukarikarabiizey village (Fig. 3). They were divided (Dean et al. 1997) into two informal members (Fig. 8), the contact of which is masked by a gap in exposure of 80 m (est.).

4.a. Lower Member

An estimated 135 m of black argillites are seen in Ketencik Dere, particularly beside the disused forestry track along the east side of the valley, but not in Akçayazi Dere. The inferred contact with the Ketencikdere Formation, about 1.5 km north of Yukarikarabiizey, is not exposed but may be faulted, and the uncommon fossils, all graptolites, are difficult to extract. Those from FOB-39 include Monograptus lobiferus (McCoy, 1850), M. triangulatus fimbriatus

(Nicholson, 1868), Rastrites cf. peregrinus (Barrande, 1850), R cf. setiger Elies & Wood, 1914, Climacograptus sp. and Glyptograptus sp., a collection indicative of the magnus and ?convolutus biozones of the middle Llandovery, Aeronian Stage (Cocks, Holland & Rickards, 1992). Graptolites from FOB-40 include Monograptus cf. crispus (Lapworth, 1876), M. exiguus (Nicholson, 1868) and M. knockensis Elies & Wood, 1913, from the crispus Biozone of the Llandovery. Samples SAF-35 and SAF-36, in the lower and upper parts of the member, lack graptolites but yielded acritarchs (Martin in Dean et al. 1997) indicative of a Llandovery age.

4.b. LTpper Member

Lollowing a gap in exposure of about 80 m, succeeding fissile, grey mudstones about 90 m (est.) thick are seen by the northeast side of the unmade readjust north of the village of Yukarikarabiizey, and in the valley southwest of the same road. The rocks are often deeply weathered to a pink or yellow rottenstone, and no identifiable acritarchs were found. A few thin (1 mm) layers yielded the following graptolites: Monograptus cf. flemingii (Salter, 1852) and Pristiograptus cf. parvus Ulst, 1974 at LOB-41; and M. flemingii at LOB-42. Both assemblages indicate the upper half of the Wenlock Series.

5. Correlation and regional relationships (WTD, OM, RBR, OD, PB)

5.a. Ordovician rocks

The Lower Palaeozoic succession of the Karadere- Zirze area differs markedly from that in the Taurides. Cambrian rocks are unknown, and the scanty evidence of (probable) Tremadoc is based on acritarchs from the lowest 13 m of the Bakacak Formation (Martin in Dean et al. 1997). The latter lithofacies is not recorded in southern Turkey, where the Seydi§ehir Formation of the Sultan Dag and Bey§ehir areas includes thin carbonate beds containing trilobite genera (Macropyge, Niobella, Onchonotellus, Proteuloma) known mostly from Europe, together with minor elements (K. (Koldinioidia), Parakoldinia) that are widespread from Mexico to Asia. The trilobites were described by Shergold & Sdzuy (1984), who assigned these faunas to the Lower Tremadoc on the basis of published evidence; later Loi, Pillóla & Leone (1996) advocated a Late Cambrian age for a similar fauna in Sardinia, but some of the genera have an extended range and may pass across the inter-systemic boundary.

The massive quartzitic sandstones of the Aydos Lormation and the graptolitic, black, anoxic mudstones of the Karadere Lormation are unknown in southern Turkey, where equivalent strata comprise thick, alternating, flysch-like siltstones and quartzites of the Seydi§ehir Lormation (Dean & Monod, 1990),

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which are mostly barren of macrofossils but may contain uncommon local developments of Cruziana Ichnofacies. In the upper half of the formation in its type area, uncommon trilobites include the typically Gondwanan genera Neseuretus and Colpocoryphe. Pelagic faunas such as graptolites and, possibly, orthoceratid cephalopods are rare in the Arenig of the Taurides, limited to a few records of Lower Arenig species from the Ovacik and Seydi§ehir areas (Rickards in Dean & M onod, 1990), and near Degirmentaj (Rickards in Özgül, Metin & Dean, 1973, p. 14), in marked contrast to the numerous levels with well-preserved, abundant graptolites at Karadere- Zirze. Of particular interest in the Taurides is the local occurrence, in laminated mudstones near Saimbeyli, eastern Taurides (Dean & Monod, 1990), of Taihungshania cf. miqueli, a species well known in the Lower Arenig of southern France and member of a genus that extended along the Gondwanan margin from France to southwestern China but is unknown from northern Europe or the Pontides.

By contrast, particularly striking in the western Pontides near Zirze is the occurrence of a low-diversity, late Arenig trilobite assemblage that would not be out of place in marginal areas of the Welsh Basin. It includes Bergamia cf. rushtoni, Cyclopyge, Dionidellcft, Leioshumardia and Selenecetne angusticaudata. The last-named, found in dark mudstones of the Upper Arenig-Lower Llanvirn in Shropshire (Shelve Inlier) and south Wales, belongs to a genus first described from the Llanvirn of Quebec, on the Laurentian m argin of Iapetus, and one of a group (including agnos- tids and shumardiids) noted by Whittington (1966, p. 728, text-fig. 15) as geographically widespread. None of these genera is known from southern Turkey, where recorded trinucleids (excluding the type Bedinan Formation, Caradoc) are extremely rare in the Upper Arenig (Sobova Formation; Dean, 1973) and in the Lower Ashgill (Sort Tepe Formation; Dean & Monod, 1990). A conspicuous difference between the northern and southern developments of Ordovician rocks involves the Llanvirn and later series. Although well represented in the Middle East, especially Saudi Arabia (El-Khayal & Romano, 1988), the Llanvirn is reported from only one faulted section near Silifke, on the south coast of Turkey (Sarmiento et al. 1999); the Llandeilo is as yet unknown from both Taurides and Border Folds, where the Caradoc and/or Ashgill (questionably present together in any one succession) are separated from Arenig or older rocks by a regional disconformity (Dean, Monod & Perinçek, 1981).

5.b. Silurian rocks

The black, graptolitic argillites in the Lower Member of the Findikli Formation are the local representatives of an anoxic lithofacies and biofacies found widely developed on a regional scale, not only in southern

Turkey, but also in the Arabian Peninsula and N orth Africa (reviews in Berry & Boucot, 1972, p. 45; 1973, pp. 5-11), as well as in southern and western Europe. In much of the Taurides, southern Turkey, Early Silurian rocks are unconformable upon Ordovician and begin typically with a thick arenaceous unit, followed in turn by black, graptolitic argillites, and by thinly bedded ‘Orthoceras Limestones’ which form the basal portion of a sequence of alternating shales and siltstone beds. All these last three lithofacies belong probably to the Lower Silurian, and in the Taurides are typified by the Halityayla Formation, Pusçutepe Shale Formation and Yukariyayla Formation (review in Dean & M onod, 1990). In the Arabian Peninsula, where they form an important oil source rock (Mahmoud, Vaslet & Husseini, 1992), black, anoxic mudstones (Qusaiba Shale) may be as old as basal Llandovery, but in the Taurides they belong generally to the middle Llandovery (Aeronian). The Silurian rocks of the Karadere-Zirze region are markedly different from those of the Taurides. No stratal equivalents of the Halityayla Formation and the ‘Orthoceras Limestones’ of the Yukariyayla Formation are yet known from the Pontides; conversely, the grey, graptolitic Wenlock mudstones of the Findikli Formation, well developed near Eregli, on the Black Sea coast 150 km west of Zirze (Egemen, 1947; Dean, unpub. data) are poorly represented in the Taurides, being described from only the Kemer area (Dean, Uyeno & Rickards, 1999).

5.C. Palaeogeographic position of the Karadere-Zirze area(OM, WTD)

In terms of age, facies and faunas the Lower Palaeozoic succession of Karadere-Zirze clearly differs from those of Gondwanan type that are known from many locations in southern Turkey, from west to east, and may be summarized as follows (Fig. 9):

(a) Perhaps the most significant feature, from a palaeogeographic point of view, is the early Ordovician age of the base of the Karadere succession. The lowest beds were initially attributed to the Cambrian on the basis of poorly preserved inarticulate brachiopods of limited stratigraphie value, but acritarch evidence suggests a probable Tremadoc age for the basal Bakacak Formation, which is directly transgressive on high- grade gneisses of unknown age. This feature clearly separates the Zirze area from the platforms of northeastern Gondwana, where lower Ordovician strata are conformable upon middle to upper Cambrian formations.

(b) A further, notable difference involves the Karadere Formation at Zirze, which indicates (on the basis of well-preserved graptolites) continuous detrital deposition from early Arenig to early Llanvirn and is followed by early Caradoc carbonates dated by means of conodonts. This portion of the Ordovician is largely unknown from southern Turkey, where a large

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SIBERIA

Figure 9. South polar view of palaeogeographic reconstruction showing postulated position of continental blocks and the Zirze unit during the early Ordovician, modified from Torsvik & Trench (1991) and Torsvik et al. (1990). Abbreviations: AR, Armorica; BO, Bohemia; NCB, North China Block; SCB, South China Block; TU, Turkey; Z, ZIRZE unit, marked by a black star.

hiatus, involving all or part of the Llanvirn (including Llandeilo), generally separates Arenig from middle Caradoc or early Ashgill detritals (Bedinan and Sort Tepe formations). As noted earlier, an exception is the small, faulted section with Llanvirn carbonates near Silifke (Sarmiento et al. 1999).

(c) At first sight the massive quartzitic beds of the Aydos Formation appear to differ from the regularly alternating, flysch-like successions of Arenig age in the Gondwanan realm, which run eastwards almost unchanged from the Montagne Noire, in southern France, to the Zap valley, in southeastern Turkey (Dean, 1980), and extend still further east, into southwestern China (Zhou, Dean & Luo, 1998). On the other hand, the Aydos Formation quartzites may perhaps be better compared with the ‘Grès armoricain’, or Armorican Quartzite, which extends from Britanny to Iberia and may also be represented in eastern Newfoundland (Dean, 1976). Both the Pontides and Franco-Spanish successions are made up of quartzose material derived from distant sources. The southern origin of the Taurides Ordovician material, although not directly proven, is indisputable on the basis of its geographic position and its links with formations of similar origin in Saudi Arabia (Vaslet, 1989), but the origin of the siliciclastic material in the Aydos Formation has yet to be established.

(d) Although some pelagic fossil assemblages (acritarchs, graptolites) may be common to the

Taurides and Pontides during both the Ordovician and the Silurian, Arenig trilobites in an admittedly small sample from Zirze are unlike faunas in the Taurides but distinctly resemble those of the Welsh Basin m argins, which then formed part of European peri- Gondwana. Conodonts and trilobites from limestones in the lower Ketencikdere Formation at Zirze are of types unknown from the Taurides, but there is a general lack of upper Ordovician carbonates in the latter region. All these areas fall within the limits of Gondwanaland cold-water Ordovician faunas as shown by Spjeldnaes (1981), and contain occurrences of cold-water acritarchs indicated later by Servais & Fatka (1997).

(e) On a regional scale, the wide geographic distribution (> 1200 km E-W ) of Lower Palaeozoic outcrops of Gondwanan type in southern Turkey contrasts markedly with the limited extent (< 80 km E-W ) of Zirze-type rocks. Further west in the Pontides, from Istanbul to Zonguldak (Fig. 1), lower Ordovician formations are developed mostly as red sandstones and conglomerates (Kurtköy Formation) of fluviatile to deltaic origin, overlain by shallow-marine quartzites of the Aydos Formation (Görür et al. 1997). This distribution implies rapid palaeogeographic changes which contrast with the extraordinarily uniform conditions of deposition on the northeastern Gondwanaland margin.

(f) According to Okay, §engör & G örür (1994) and Görür et al. (1997), the most probable location of the Palaeozoic succession of the Istanbul-Zonguldak fragment during the Carboniferous was along the margin of Laurasia, from which it became detached as the Black Sea opened during late Cretaceous times. The Lower Palaeozoic formations described from the region of Dobroudja (or Dobrogea), in Romania- Bulgaria, are comparable with those at Zirze.

A tentative palaeogeographic reconstruction of continental blocks and oceanic areas during the early Ordovician is presented in Figure 9, modified from Torsvik & Trench (1991) and Torsvik et al. (1990). In this figure, and along the margin of Gondwanaland, Avalonia, Armorica (AR) and Bohemia (BO) are shown situated close to one another, whereas southern Turkey (TU, in black) is tentatively assigned to a position at the eastern end of the present-day Mediterranean. A possible location for the Zirze unit (indicated by a black star) is indicated in the vicinity of the central European and Anglo-Welsh successions which contain similar trilobite faunas. Although southern Turkey contains Ordovician faunas distinct from those of the Pontides, it too belongs to the Gondwanaland margin and is sited high in southern latitudes. However, in this reconstruction both regions appear on opposite sides of the South Pole, and one may ask whether the polar zone might have acted as an effective barrier to the migration of benthic faunas along the Gondwana continental margin.

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6. Palaeontological notes

All the material considered here is from localities whose geographic positions are shown in Figures 3 and5, and whose estimated relative stratigraphie levels are shown in Figures 6, 7, 8 and 13. Prefixes of figured and cited specimen numbers denote the following repositories: NM W 95.34G. - National Museum of Wales, Cardiff; SM. X. - Sedgwick Museum, Cambridge.

6.a. Ordovician graptolites (RBR)

6.0.1. Grap to lo id biostratigraphy

The stratigraphie occurrence of species, all from the Karadere Formation, is plotted (Fig. 13) against the sequence of localities and levels, and their deduced chronos- tratigraphic age. Levels FOB-5/OFB-3 to FOB-8/OFB-8 are unquestionably Arenig in age; and those from from FOB-30 to FOB-15/OFB-11 & FOB-34 are certainly Llanvirn, based upon the occurrence of D. (Didymograptus) artus, D. (D.) spinulosus and D. (D.) pseudogeminus. Between these two sets of localities, levels FOB-12/OFB-9 to O FB-10 are, in terms of graptolite faunas, essentially transitional between Arenig and Llanvirn. I conclude that these beds are, on balance, best considered as Arenig, based on the following criteria:

(1) Didymograptus (Expansograptus) nitidus {Haii, 1858) occurs through most of the transitional sequence and is best regarded as an Arenig species;

(2) Oelandograptus austrodentatus (Harris & Keble, 1932), typically a hirundo Biozone species, occurs in the lowest beds of the transitional sequence, as does O. oelandicus (Bulman, 1963), again typically Arenig;

(3) D. (Corymhograptus) vfractus volucer Nicholson, 1890 is also an Arenig species.

Of the remaining species Aulographis cucullus (Bulman, 1932) occurs in both series. A í aff. feistmanteUi (Boucek, 1973) may be distinct from Boucek’s Llanvirn species and hence has no immediate value; while the form attributed to Prolasiograptus, itself more likely to be Llanvirn, is new, and the same value can be placed upon it as upon A í aff. fe istmanteUi. O f the certain identifications, only Eoglyptograptus bouceki sp. nov. remains to be considered, and as a new species it cannot yet be recorded as stratigraphically important, although it may be a precursor of Llanvirn species. It must be said, however, that the occurrence of one doubtful specimen of Cryptograptus plus the presence of Prolasiograptus and an Eoglyptograptus species suggests a hirundo Biozone level very close to the base of the Llanvirn.

Returning to the lower, certainly Arenig strata (FOB- 5/OFB-3 to FOB-8/OFB-8), Isograptus caduceus imitatus Harris, 1933, which occurs in the lowest beds, was recorded by Cooper & Fortey (1982) from the hirundo Biozone of Spitsbergen. On the other hand Azygograptus eivionicus Elies, 1922 is normally regarded as a middle Arenig form, so the qualification of cf. may be important in this context. Of the remaining forms in these lower beds Pseudisograptus manubriatus koi Cooper & Ni, 1986 (OFB-7) was recorded by its authors from the lower Yapeenian, that is, about the hirundo level, but the lowest locality could be pre-hirundo and referable to the nitidus (renamed simulans in Cooper et cd. 1995) or gibberulus biozones. Acrograptus gracilis (Törnquist, 1890) and D. (Didymograptellus) protobifidus Elies, 1933 (FOB-5) do suggest a pr e-hirundo level, but the other forms are not so discriminating as regards age. These

Turkish sections may prove highly important in terms of graptolite evolution, for the undoubted early occurrence of several biserial forms is established in this paper, and the origin of the biserial genera poses one of the real problems of graptoloid evolution.

6.a.2. Introduction to graptoloidsystematics

The text avoids descriptions of those forms where there is little to add to previous accounts, and of those recorded in the range chart (Fig. 13) the following are not described: Tetragraptus bigsbyi (Haii, 1865), T. quadribrachiatus (Haii, 1865), Didymograptus nitidus (Haii, 1865), D1 uniformis lepidus Ni, 1979, D. cf. deflexus (Elles & Wood, 1901), D. vfractus volucer Nicholson, 1890, Pseudophyllograptus a. angustifolius (Haii, 1865), Sigmagraptus sp., Acrograptus gracilis, Oelandograptus austrodentatus (Ham s & Keble, 1932) and ICryptograptus sp. The doubtful attributions in this list are due to problems of preservation rather than a recording of some differing feature, and their biostratigraphic significance is discussed in Section 6.a.i.

The classification adopted largely follows those of Cooper & Fortey (1982) and Rickards & Chapman (1991) for the dichograptids, but differs from the most recent classification of the diplograptids (Mitchell, 1987; see list at end of this section). The main differences from Mitchell’s classification reflect doubts about his definitions of the Monograptidae; despite the case established by him, I feei that glyptograptids such as the Eoglyptograptinae and Glyptograptinae should be retained in the Diplograptidae and not the Monograptidae. To adopt the latter policy is to render difficult, without repeated ‘translations’, the use of a vast tract of past publications. The classification adopted here does not materially affect Mitchell’s (1987) phylogenetic story; indeed, plotting his development types (see list below) against our recorded forms seems broadly in accord with the general evolutionary developments.

No new morphological terms are introduced in this paper, which largely follows Bulman (1970) and Cooper & Fortey (1982). Thecal spacing is given in the sense of Packham (1962) because I regard his technique as successful in resolving small changes along the stipe, while at the same time enabling fairly ready comparisons to be made with more traditional recordings such as ‘thecae per cm’. The following descriptions are not necessarily full but emphasize the most important, or different, features from previous work. The following is my classification of the species identified: an asterisk (*) indicates a form not described; figure numbers for forms illustrated but not described are shown in parentheses.

Order GRAPTOLOIDEA Lapworth in Hopkinson & Lapworth, 1875

Family d ic h o g r a p t id a e Lapworth, 1873 Subfamily d ic h o g r a p t in a e Lapworth, 1873

Genus Tetragraptus Salter, 1863 Subgenus T. ( Tetragraptus) Salter, 1863

T. (Tetragraptus) bigsbyi (Haii, 1858) * (Fig. 14a,b) Subgenus T. (Eotetragraptus) Boucek&PHbyl, 1951

T. (Eotetragraptus) quadribrachiatus (Haii, 1858) * Genus Aulograptus Skevington, 1965

A. cucullus (Bulman, 1932)A í aff. feistmanteUi’Boucek, 1973

Genus Didymograptus McCoy, 1851Subgenus D. (Didymograptus) McCoy, 1851

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D. (Didymograptus) spinulosus Ferner, 1895 D. (Didymograptus) pseudogeminus Boucek, 1973 D. (Didymograptus) artus Elies & Wood, 1901

Subgenus D. (Didymograptellus) Cooper & Fortey, 1982 I). (Didymograptellus) »//>///?/« Törnquist, 1879 I). (Didymograptellus) protobifidus Elies, 1933

Subgenus D. (Expansograptus) Boucek & Pfibyl, 1953 D. (Expansograptus) nitidus {Haii, 1858) * (Fig. 15i,j,l) I). (?Expansograptus) uniformis lepidus Ni, 1979 * (Fig. 15k)

Subgenus D. (Corymbograptus) Obut & Sobolevskaya, 1964

D. ( Corymbograptus) cf. deflexus (Elies & Wood, 1901) (Fig. 15o)I). (Corymbograptus) vfractus volucer Nicholson, 1890 * (Fig. 15n)

Genus Pseudophyllograptus Cooper & Fortey, 1982 P. a. angustiformis {Haii, 1858) *

Genus Azygograptus Nicholson & Lapworth in Nicholson, 1875

A. cf. eivionicus Elies, 1922

Subfamily s ig m a g r a p t in a e Cooper & Fortey, 1982 Genus Sigmagraptus Ruedemann, 1904

Sigmagraptus sp. *Genus Acrograptus Tsai, 1969

A. gracilis (Törnquist, 1890) *

Subfamily is o g r a p t in a e Harris, 1933 Genus Isograptus Moberg, 1892

I. caduceus imitatus Harris, 1933 Genus Pseudisograptus Beavis, 1972

P. manubriatus koi C ooper& N i, 1986

Family d ip l o g r a p t id a e Lapworth, 1873 non Mitchell, 1987

Subfamily e o g l y p t o g r a p t in a e Mitchell, 1987 emend, herein

Genus Oelandograptus Mitchell, 1987 Subgenus O. ( Oelandograptus) ex Mitchell, 1987

O. ( Oelandograptus) oelandicus (Bulman, 1963)Genus Eoglyptograptus Mitchell, 1987

E. jaroslavi (Boucek, 1973)E. bouceki sp. nov.

Subfamily c l im a c o g r a p t in a e Freeh, 1897 Genus Prolasiograptus Lee, 1963

P. haplus praecursor subsp. nov.Genus Climacograptus Haii, 1865

Subgenus C. ( Climacograptus) Haii, 1865C. ( Climacograptus) angustatus Ekstvöm, 1937

Family g l o s s o g r a p t id a e Lapworth, 1873 Genus Cryptograptus Lapworth, 1880

ICryptograptus sp. *

6. a. 3. Systematic descrip Hons

Family d ic h o g r a p t id a e Lapworth, 1873 Subfamily d ic h o g r a p t in a e Lapworth, 1873

Genus Aulograptus Skevington, 1965 Aulographis cucullus Bulman, 1932

(Fig. lOc-f)

1932 Didymograptus cucullus n. sp., Bulman, p. 15, text-fig.1; pi. 1, figs 1-8.

1965 Aulograptus cucullus (Bulman), Skevington, p. 26, figs 20-33.

Material. Fairly abundant at three levels, FOB-12/OFB-9, FOB-14 and OFB-10 (Fig. 13); preserved in moderate three dimensions, infilled by ferruginous material, probably goethite.

Remarks. The early development is clearly seen (Fig. 1 Of) and is isograptid dextral in the sense of Cooper & Fortey (1982). The origin of th l1 is not clear but may be as low as 0.5 mm from the sicular aperture. The early growth of th l2 is robust, but that of th2', deriving from it, is very slender and tube-like, exactly as illustrated by Skevington (1965). T h l2 is dicalycal. New thecae arise at about the level of the preceding thecal aperture and there is a gently prothecal fold, though its nature is obscure. Thecal spacing at 12-13 in 10 mm is not very different from the usually quoted 13-14 in 10 mm, and other dimensions are closely comparable. Prothecal folding, though very slight, seems not to have been noticed before. A few specimens have only a single stipe developed (Fig. 10c) and in these cases th2' derives from th l1, as far as can be seen. The single-stiped specimens appear not to be the result of breakage.

Aulograptusl aff. feistmanteUi'Boucek, 1973 (Fig. 10g,h)

1944 Didymograptus climacograptoides Bulm. mut., Boucek, p. 232.

1944 Didymograptus climacograptoides Bulm. bohemicus n. subsp., Boucek, p. 2.

1973 Aulographis)?) feistmanteUi sp. n., Boucek, p. 73, text-figs 22b-f; pi. 2, figs 1-2.

Material. A few specimens from two horizons (FOB- 12/OFB-9, FOB-13, Fig. 13), preserved in the same manner as A. cucullus.

Remarks. This form is remarkably similar in form and size to A. cucullus but has dichograptid rather than climacograptid thecae. This is not a matter of preservation, as well-preserved profile views are present in both species (cf. Fig. 10c,g). Development is isograptid dextral with t h l1 dicalycal but the early part of th2! may be more robust than in A. cucullus. This material differs from the original of the species

Figure 10. (a, b) Tetragraptus bigsbyi (Haii), SM X .26722 and X.26723 respectively, FOB-34, Llanvirn. (c-f) Aulograptus cucullus (Bulman), SM X.26724 to X .26727 respectively, FOB-14, Arenig, transitional to Llanvirn. (g, h) Aulograptusl ML feistmanteUi Boucek, SM X .26728 and X.26729 respectively, FOB-13, Arenig, transitional to Llanvirn. (i l) Didymograptus spinulosus Perner, SM X.26730 to X.26733 respectively, FOB-15, Llanvirn. Scale bars = 1 mm. Localities and horizons are shown in Figure 13.

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Lower Palaeozoic biostratigraphy, Pontus Mountains

Figure 10. For legend see facing page.

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in thecal spacing (13-16 in 10 mm; cf. 10-13 in 10 mm in the types) and in having slightly more slender stipes (0.30-0.40 proximally and 0.50 distally; cf. 0.40-0.50 and 0.70-0.90). There is a slight undulation (? prothecal folds) of the dorsal stipe margin in the Turkish specimens which is not apparent in Boucek’s original illustrations.

Ä1 feistmanteUi is a Llanvirn species and the Turkish specimens are perhaps best regarded as an Arenig forerunner; certainly they are closely related. The tendency to include this form in Aulograptus, adopted by Boucek (1973) and herein, may be in error for it certainly lacks climacograptid thecae, while having a slight geniculum. Boucek considered A. cucullus a (later) more advanced form in which climacograptid thecae had evolved. However, A. cucullus itself is known from the Arenig of several areas and indeed occurs with .4? aff. feistmanteUi at FOB-12 (Fig. 13). The Turkish specimens are even closer to A. cucullus on dimensional grounds than Boucek’s Llanvirn specimens of .4? feistmanteUi. His suggested evolutionary line may yet prove valid, and the origin of .4? aff. feistmanteUi may lie in a small D. (Didymograptus) with a low origin of th l f

Genus Didymograptus McCoy, 1851 Subgenus D. (Didymograptus) McCoy, 1851 D. (Didymograptus) spinulosus Perner, 1895

(Fig. lOi-1)

1895 Didymograptus spinulosus n. sp., Perner, p. 39, pi. 5, figs 9-10. For further synonymy, see Boucek (1973) and Fortey & Owens ( 1987).

Remarks. The material, comprising several specimens from FOB-15/OFB-11 (Fig. 13), is identical to previously described forms, especially the types, and is typified by a long, spine-like sicula and a low origin of t h l1 as claimed by Fortey & Owens (1987). There is some variation in robustness of the proximal end (cf. Fig. 10i,j), but in Figure lOi this is almost certainly a result of late peridermal addition which seems especially to affect those specimens where the stipes are close together, more parallel than diverging. Within the Turkish collections, D. (D.) spinulosus can be contrasted with the more robust D. (D.) pseudogeminus, which occurs at the same level and also has a lower thecal spacing. D. (D.) artus is an altogether smaller species with more slender stipes, thecae at a lower angle of inclination, and usually a higher thecal spacing.

D. (Didymograptus) pseudogeminus Boucek, 1973 (Fig. I la )

1973 D. (Didymograptus) pseudogeminus sp. n., Boucek, p. 93, text-fig. 29a-g; pi. 14, figs 2-3; pi. 15, figs 1-4.

Material. A small number of specimens (< 10) from FOB- 15/OFB-l 1 (Fig. 13), preserved in low relief.

Description. One specimen (Fig. I la ) strongly suggests a low origin for th l1, although others may be secondarily thickened and the proximal end around the sicula looks more robust. The stipes are robust, achieving distally a dorso-ventral width of 2.80 mm and a thecal spacing of 11-12.5 in 10 mm. The angle of thecal inclination is around 45° distally, and only veiy close to the proximal end does it become much less. The proximal development is not clear, but I am inclined to refer D. pseudogeminus to D. (Didymograptus) rather than to D. (Didymograptellus). The specimens are slightly

deformed tectonically and the dorso-ventral width, thecal spacing and angle of thecal inclination may be reduced slightly. For differences from other didymograptids in the collection, see remarks for D. (D.) spinulosus.

D. (Didymograptus) artus Elies & Wood, 1901 (Fig. 1 lb,c)

1901 Didymograptus (Didymograptus) artus sp. nov., Elies & Wood, p. 48, text-fig. 30; pi. 4, figs 6a-d.

1987 Didymograptus (Didymograptus) artus Elies & Wood, 1901; Fortey & Owens, p. 258, figs 112b d, 113. Includes synonymy.

Material. Moderately abundant (>10 specimens) at two levels, FOB-30 and FOB-33 (Fig. 13).

Remarks. The thecal spacing on our specimens is 15-18 in 10 mm, the mean being 16.5, and is thus slightly lower than for typical specimens (see, for example, Fortey & Owens, 1987, p. 258). In all other measurable characters the material closely resembles previous descriptions. The early development is not very clear, but th l1 seems to be the dicalycal theca (Fig. Ile) and certainly has a low origin on the sicula. Specimens are undeformed and in low relief, with growth lines visible in only a few places. In Figure 1 lb the crossing canal is seen ‘pressed through’ and the sicular aperture is obscure. In his recent paper on Yutagraptus, Riva (1993) defined the development of Didymograptus (Didymograptus) in this way, thus supporting the conclusions of Cooper & Fortey (1982) and of Fortey & Owens ( 1987), with which I concur.

Subgenus D. (Didymograptellus) Cooper & Fortey, 1982 I). (Didymograptellus ) minutus Törnquist, 1879

(Fig. lid ,e)

1879 Didymograptus minutus n. sp., Törnquist, p. 447, figs 1- 2 .

1973 Didymograptus minutus minutus Törnquist; Boucek, p. 73, figs 24a-d. Includes synonymy.

Material. A small number of specimens (< 10), preserved in three dimensions but weathered, from FOB-7 (Fig. 13).

Remarks. Stipe dorso-ventral widths at the levels of t h l1 and th l2 are slightly narrower than given by Boucek (1973) at 0.30-0.50 mm (cf. 0.40-0.50), but this may be partly explained by the fact that our material is in relief. Distal width never exceeds 0.70 mm, and in this and the thecal spacing the Turkish specimens are in full accord with earlier descriptions. Although Boucek (1973) gave a thecal spacing of 12-13 in 10 mm, his figures show a range of 12-16 in 10 mm, the same as our material. The sicula may be as long as 2 mm in some specimens, but is narrow with indications of a high sicular origin of t h l1; apart from this, development is obscure where th l2 originates. Isograptid development in this material is assumed, but not proven.

Within the Turkish collection I). (Didymograptellus ) minutus differs from D. (D. ) protobifidus (see below) in that the latter is more robust and has the typical ‘triangular sicula’ of a species with high th l1 origin. The other didymograptids differ as discussed in the foregoing descriptions, with their clear reference to D. (Didymograptus).

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I). (Didymograptellus) protobifidus Elies, 1933 (Fig. I l f h) '

1933 Didymograptus protobifidus sp. nov., Elies, p. 98, text- fig. 1 only (non 2, 3).

1982 Didymograptus (Didymograptellus) protobifidusElies, 1933’; Cooper & Fortey, p. 230, figs 35a-d; pi. 2, fig. 1. Includes synonymy.

Material. Common at FOB-5, the lowest horizon in the Karadere Formation sampled at Karadere (Fig. 13). All the specimens are flattened and slightly deformed, showing growth lines in places.

Remarks. The sicula is broadly triangular, roughly 1.0-1.25 mm long, and bears a slender virgella. The origin of t h l1 is quite high, as is the origin of th l2, and the two thecal tubes growing downwards contribute to the broad, triangular appearance. The sicular aperture turns away from the free ventral wall of t h l1, and there is a rounded re-entrant angle between the free ventral wall of th l1 and the ventral side of the sicula (sensu Riva, 1993). T h l2 is apparently dicalycal, though this cannot be proved. It is not easy to compare the thecal spacing of the proximal ends with figures from more fully grown specimens, but the dimensions seem closely similar to examples illustrated by Cooper & Fortey (1982, figs 35a,b).

Genus Azygograptus Nicholson & Lapworth in Nicholson, 1875

Azygograptus cf. eivionicus Elies, 1922 (Fig. 11m)

cf. 1922 Azygograptus eivionicus sp. nov., Elies, p. 299. cf. 1987 Azygograptus eivionicus Elies; Fortey & Owens, p.

276, figs 128a, 129.

Material. Fairly common, but badly preserved, flattened, with few proximal ends, in black shale from FOB-5/OFB-3 and OFB-2/OFB-5, the two lowest levels sampled in the Karadere Formation (Fig. 13).

Remarks. The sicula has a length of 1.10-1.20 mm in the Turkish material, similar to that given by Fortey & Owens (1987) for Welsh specimens; and the thecal spacing is identical to their material (distance between thecal apertures = 1.30-1.50 mm). The Turkish specimens are on average a little straighter than the Welsh, though some stipes do show gentle curvature. Stipe widths seem central to the range given by Fortey & Owens, with a maximum of 0.80 mm most distally. Early development is not clear and the sicular spine typical of the species has not been seen. This is almost certainly a reflection of the few proximal ends, which are indifferently preserved.

Subfamily is o g r a p t in a e Harris, 1933 Genus Isograptus Moberg, 1892

Isograptus caduceus imitatus Harris, 1933 (Fig. l ip )

1933 Isograptus caduceus var. imitata var. nov., Harris, p. 92, figs 55-59.

1982 Isograptus caduceus imitatus Harris, 1933; Cooper & Fortey, p. 252, figs 54a-d.

Material. A small number of specimens (< 10), preserved in low relief, from FOB-5, the lowest level sampled in the Karadere Formation at Karadere.

Remarks. The Turkish specimens closely resemble those from Spitsbergen described by Cooper & Fortey (1982). The V-shaped nature of the rhabdosome is closest to forms in their figure 54c, that is, with a veiy slight rounding of the angle between the stipes and the downgrowing early thecae on the sicula. The stipe width, stipe angle, thecal spacing and thecal angles are all closely similar to the Spitsbergen material, as are the sicular length and growth of the early thecae. The main difference in the Turkish specimens is that the earliest parts of the stipes, as they grow away from the sicular region, are slightly more slender (2.0 mm cf. 2.10-2.30 mm) and the thecae less crowded there, so that the maximum dorso-ventral stipe width is not reached until th4 or th5 (cf. th l2 or th2 in Spitsbergen specimens). Thereafter, the stipe width declines gradually in the usual way. This difference may, in fact, reflect rather poor preservation of the proximal end on our specimens; the stipe width may be greater proximally than shown.

Genus Pseudisograptus Beavis, 1972 Pseudisograptus manubriatus koi Cooper & Ni, 1986

(Fig. 1 lq,r)

1986 Pseudisograptus manubriatus koi sp. nov., Cooper & Ni, p. 332, pi. 24, figs 1-6, 9-12; pi. 25, figs 3, 4; text- figs 12, 13A-G, J.

Material. A small number of specimens (< 10), early growth stages, preserved in three dimensions on the two small slabs fromOFB-7.

Remarks. On all grounds of development and dimensions this conspicuously manubriate form fits well with P. manubriatus as redefined by Cooper & Ni (1986), and the sicular length, especially, equates the Turkish specimens with their subspecies P. m, koi. Together with the type subspecies, P. m. koi has the shortest sicula of the series but is distinguished from the former in having a deeper V between manubrium and stipes, and a less robust manubrium. On the specimen depicted in Figure Hr, the stipes may be more developed than shown, but the preservation permits neither the sicular and thecal apertural regions nor the full extent of the stipes to be seen clearly.

Family d ip l o g r a p t id a e Lapworth, 1873 non Mitchell, 1987 Subfamily e o g l y p t o g r a p t in a e Mitchell, 1987

Genus Oelandograptus Mitchell, 1987 Subgenus Oelandograptus ex Mitchell, 1987

O. ( Oelandograptus) oelandicus (Bulman, 1963)(Fig. 12a-c)

1936 G. dentatus (Brongniart); Bulman, Part VII, p. 49, pi.3, figs 5-7, 12-21; pi. 4, figs 4-6; text-fig. 18-2.

1963 Glyptograptus austrodentatus var. oelandicus var. nov. Bulman, p. 682, pi. 97, figs 16, 17; text-figs 2a-d, 8.

Material. Five specimens from FOB-12 (Fig. 13), preserved in three dimensions and probably originally pyritized, now probably goethite.

Remarks. The material is identical with that described by Bulman (1963) from the Orthoceras Limestone of Öland, Sweden, agreeing in development, rhabdosome width, thecal spacing, thecal type and, especially, in the slightly more upward growth of t h l1 and th l2 which contrasts them with Oelandograptus austrodentatus. The characteristic distal thecae of this form (Bulman, 1963, text-fig. 8a) are not seen in

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the Turkish material, but signs of the supragenicular wall becoming more steeply inclined are already present more proximally on some specimens (Fig. 12c). There are no traces whatever of spines or spine bases on th l1 or th l2 (or any subsequent thecae). Mitchell (1987) accorded Oelandograptus Group A status, and our material tends to support this attribution.

Genus Undulograptus Boucek, 1973

The type species, designated by Boucek, is Pseudoclimacograptus formosus Mu & Li, 1958, from Western Chekiang, and not Climacograptus paradoxus Boucek as stated by Mitchell (1987).

Undulograptus? m ui sp. nov.(Fig. 12d,e)

Holotype. SM X.26755, from OFB-8, at the road section southeast of Zirze. The age is Arenig, and the associated fauna includes Didymograptus nitidus (?), possible Sigmagraptus sp., Tetragraptus bigsbyi and Pseudophyllograptus a. angustifolius. Preservation is in three dimensions, undeformed, infilled probably with goethite. A proximal end (Fig. 12e, SM X.26756) may belong to this species.

Derivation o f name. In honour of the Chinese graptolitholo- gist, the late Professor A. T. Mu.

Diagnosis. Robust, uniform biserial, probably with Group A development (Mitchell, 1987); pseudoclimacograptid-like, complete median septum, undulating to zigzag, with projecting lists into the prothecae; thecae long, multisigmoidal tubes with overlap of 2/3; conspicuous apertural spine-like processes directed proximo-ventrally; adaxial transverse narrowing of the thecal aperture; t h l1 directed sub-horizon- tally; th l2 slightly upwardly growing in free ventral region; sicula at least 1.5 mm long, probably reaching the third thecal pair; virgella robust, directed slightly towards the second thecal series; thecal spacing 13 in 10 mm; average thecal inclination 15°-17°; average thecal (dorso-ventral) width 0.25 mm, widening aperturally to 0.50 mm.

Remarks. The above combination of characters is recorded nowhere in the literature; it includes in particular an austrodentatus-like (or Oelandograptus-like) proximal development, together with pseudoclimacograptid-like median septum, coupled with apertural processes throughout the colony. The new species is referred doubtfully to Undulograptus, although there is a case for referring it to Oelandograptus or Pseudoclimacograptus. From the former

it differs in the pronounced nature of its thecal septum; from the latter it differs in having glyptograptid thecae; and from all three genera it differs in having pronounced apertural processes. Further work on other material may indicate reference to a new genus.

Genus Eoglyptograptus Mitchell, 1987 Eoglyptograptus jaroslavi (Boucek, 1973)

(Fig. 12f,g)

1973 Pseudoclimacograptus ( Undulograptus) jaroslavi n. sp., Boucek, p. 124, pi. 21, fig. 7; pi. 22, fig. 7; figs 36d, 37a, b.

Material. About twenty-five specimens on one slab from FOB-33 (Fig. 13); almost flattened but well preserved, with slight tectonic deformation. Age, early Llanvirn.

Diagnosis. Uniform biserial with glyptograptid thecae having a flowing geniculum throughout the length of the colony; thecal spacing 12-14 in 10 mm proximally and 11-13 in 10 mm distally; t h l1 and th l2 without spines; virgella and nema conspicuous, robust, the latter expanding into a narrow vane; thecal inclination 20°-25°; thecal overlap 1/3 proximally to 1/2 distally; ?septate; sicula about 1.25 mm long; dorso-ventral width 1.5 mm after 5-10 mm.

Remarks. The Turkish specimens are particularly close to the specimen originally figured by Boucek (foc. cit. ) as pi. 21, fig. 7 and pi. 22, fig. 7, and the only detectable differences are in thecal spacing; although Boucek did not give a thecal spacing for the species, a figure of about 10 in 10 mm can be calculated from his illustrations. Variation in the type material is uncertain, as Boucek had only two specimens. Whether Mitchell (1987) is correct in assigning Group B development to the species cannot be ascertained from our material. It seems likely, but the virgella is robust and may not necessarily be short; one specimen may have a virgella 4 mm long.

Eoglyptograptus bouceki sp. nov.(Fig. 12h-j)

Holotype. SM X.26759 (Fig. 12h), from FOB-12, beside the unmade road southeast of Zirze (Fig. 5). Age, late Arenig.

Paratypes. Numerous three-dimensional specimens (including SM X.26760 and X.26761) from FOB-12, FOB-13 and OFB-10, southeast of Zirze (Fig. 5). Age, late Arenig.

Derivation o f name. In honour of the late Professor Bedfich Boucek.

Figure 11. (a) Didymograptus pseudogeminus Boucek. SM X.26734, FOB-15, Llanvirn. (b, c) Didymograptus artus Elies & Wood, SM X.26735 (FOB-30) and X.26736 (FOB-33) respectively, Llanvirn. (d, e) Didymograptus (Didymograptellus) minutus Törnquist, SM X.26737 and SM X.26738 respectively, FOB-7, Arenig. (f-h) D. (Didymograptellus) protobifidus Elles, SM X.26739 to X.26741 respectively, FOB-5, Arenig. (i, j, 1) Didymograptus (Extensograptus) nitidus (Haii), SM X.26742 and X.26743 (FOB-12), and SM X.26744 (FOB-13) respectively, Arenig, transitional to Llanvirn. (k) Didymograptus (Extensograptus) uniformis lepidus Mu, SM X.26745, FOB-13, Arenig, transitional to Llanvirn. (m) Azygograptus cf. eivionicus Elies & Wood, SM X.26746, OFB-5, Arenig. (n) Didymograptus (Corymbograptus) vfractus volucer Nicholson, SM X.26747, FOB-5, Arenig. (o) D. (Corymbograptus) cf. deflexus (Elies & Wood), SM X.26748, FOB-3, Arenig. (p) Isograptus caduceus imitatus Harris, SM X.26749, FOB-3, Arenig. (q, r) Pseudisograptus manubriatus koi Cooper & Ni, SM X.26750 and X.26751, OFB-7, Arenig. Scale bars = 1 mm; heavy bars indicate tectonic stretching direction, where appropriate. Localities and horizons are shown in Figure 13.

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Figure 12. (a-c) Oelandograptus oelandicus (Bulman), SM X.26752 to X.26754 respectively, FOB-12, Arenig, transitional to Llanvirn. (d, e) Undulograptus mui sp. nov., SM X.26755 (holotype) and X.26756 respectively, OFB-8, Arenig. (f, g) Eoglyptograptus jaroslavi (Boucek), SM X.26757 and X.26758 respectively, FOB-33, Llanvirn. (h-j) Eoglyptograptus bouceki sp. nov., SM X.26759 (holotype), X.26760 and X.26761 respectively, FOB-12, Arenig, transitional to Llanvirn. (k, 1) Climacograptus angustatus Ekström, SM X.26762 and X.26763 respectively, FOB-34, Llanvirn. (m) Prolasiograptus haplus praecursor subsp. nov., SM X.26764 (holotype), OFB-9, Arenig, transitional to Llanvirn. Scale bars = 1 mm; heavy bars indicate tectonic stretching direction, where appropriate. Localities and horizons are shown in Figure 13.

Diagnosis. Robust glyptograptid lacking any proximal spines; fully septate with undulating septum lessening only slightly distally. Multisigmoidal thecae spaced at 14 in 10 mm proximally and 12 in 10 mm distally; overlapping about 1/2 and inclined at 10°-20°; thecal length from 1.0 mm proximally to 1.25 mm distally; supragenicular wall inclined outwards at 5°-10°. Sicula possibly only 1 mm+ long, not reaching second thecal pair; virgella robust, long, and expanded to a narrow vane; dorso-ventral width maximum 1.50 mm; development possibly Group B.

Remarks. The proximal development is not clearly seen but the relatively broad, rounded proximal end and the conspicuous th l1 tend to suggest several crossing canals and Group

B development. However, as in the case of E. jaroslavi, the robust and possibly long virgella does not accord with Mitchell’s (1987) original definition of Group B development; possibly this feature of the definition should be revised. E. bouceki bears a superficial resemblance to Pseudoclimacograptus klabavensis Boucek, 1973 andT! paradoxus (Boucek, 1973) but the latter has rather long thecae and, consequently, a low thecal spacing of only 9 in 10 mm, and the former may well have a zigzag median septum with associated lists, which is why Boucek (1973) placed it in P. (Pseudoclimacograptus). E. bouceki can be contrasted with most early glyptograptids, for example, those related to Glyptograptus teretiusculus (Hisinger, 1840), in its total lack of thecal spines at the proximal end; there are similarities to

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such forms as G. euglyphus (Lapworth, 1880), but the new species differs in thecal spacing as well as in the complexity of proximal development (Group B in E. bouceki and Group H in G. euglyphus).

Subfamily c l im a c o g r a p t in a e Freeh, 1897 Genus Prolasiograptus Lee, 1963

Prolasiograptus haplus praecursor subsp. nov.(Fig. 12m)

Holotype. S M X .26764 (Fig. 12m), fromFOB-12 at the road section southeast of Zirze (Fig. 5). Age, late Arenig.

Paratypes. Two specimens, SM X.26765, X.26766, on same slab as holotype.

Diagnosis. Robust, almost parallel-sided rhabdosome with maximum dorso-ventral width of 2.40-2.50 mm and thecal spacing of 16 in 10 mm proximally to 12 in 10 mm distally; septate; sicula 1.40 mm long, reaching apertures of second thecal pair; virgella small; thecal inclination 15°-20°; thecal length 1.25-1.50 mm; thecal overlap about 1/2; after t h l1 and th l2 (which lack spines) the supragenicular wall changes from nearly vertical (to th4) to strongly inclined inwards; geniculae are sharp but not spinose; thecal apertures horizontal to slightly everted.

Remarks. These are problematical fossils in that they have a superficial resemblance to Oelandograptus, especially to those forms with upward opening th l1 and th l2, such as the type species. O. oelandicus also has (usually) distal thecae in which the distal end of the free ventral wall becomes subvertical (see, for example, Bulman, 1963, text-fig. 8d after Skevington) thus effecting a geniculum of sorts. O. oelandicus may also lack proximal spines and the general dimensions, such as thecal spacing, are similar. Flowever, the Turkish specimens, which occur in the same beds as O. oelandicus, at FO B -12, show a clear inwardly sloping supragenicular wall exactly as seen in lasiograptids. Thus the new subspecies is assigned to Prolasiograptus, a genus defined by Lee (1963) on the absence of any thecal process, whether proximal or distal.

The Turkish specimens are veiy similar to Lasiograptus haplus Jaanusson (1960), agreeing in rhabdosome size and thecal spacing, although they show no good evidence of the median septum. The supragenicular wall in P. h. praecursor is slightly less inwardly sloping, and the rhabdosome as a whole possibly larger, than in the type subspecies. I suggest that a line of descent from O. oelandicus to P. h. praecursor is distinctly possible, leading to P. h. haplus at a still higher level (approximately murchisoni!teretiusculus); involved in this would be a change from early development of Group A in O. oelandicus to Group C in P. haplus haplus. The development in P. h. praecursor cannot be deduced in the present material.

Genus Climacograptus Flail, 1865 Subgenus C. ( Climacograptus) ex Flail, 1865

C. (Climacograptus) angustatus Ekström, 1937 (Fig. 12k,1)

1937 Climacograptus angustatus n. sp., Ekström, p. 36, pi. 7, figs 1-6.

71970 Climacograptus tailbertensis sp. nov., Skevington, p. 412, figs4a-c.

Material. Several specimens, preserved almost flattened, from FO B -15, at the north end of Akçayazi Dere, southeast of Zirze; and FOB-34, in Ketencik Dere, south-southeast of Zirze (Fig. 3). Age, early Llanvirn.

Diagnosis. Slender climacograptid reaching a dorso-ventral width of 1.50 mm; almost parallel-sided after first 7 mm; thecae distinctly climacograptid, with deep, short excavations and a vertical to slightly outwardly inclined supragenicular wall; thecal spacing 11 in 10 mm proximally and distally; virgella robust; ?septate; no spines on th l1 or th l2. Thecal length, overlap and inclination not observable in this material.

Remarks. Simple, slender climacograptids, lacking proximal thecal spines have been described before from the Llanvirn, and in addition to C. tailbertensis, Skevington (1970) described the veiy similar Climacograptus sp. and C. sp. nov. Both have a higher thecal spacing than the Turkish specimens, which are not tectonically deformed, and only a few specimens are referable to either species. In addition we must consider C. celsus Ekström, which has similar thecal spacing but a more robust rhabdosome closer to C. antiquus, though lacking the latter’s proximal thecal spines. Ekström’s specimens of C. angustatus from throughout the Upper Didymograptus Shales of Fâgelsâng and Nyhamnsläge, Sweden, may be at a higher level than the Turkish specimens or, at least, persist to a high stratigraphie level. The species may be a forerunner of C. celsus Ekström, C. antiquus Lapworth (some examples of which may lack spines on th l1 and th l2) and possibly C. tailbertensis, C. sp. and C. sp. nov. of Skevington. The Turkish associates of C. angustatus (Fig. 13) suggest the pve-clavulus levels of Ekström’s sections; hence the material is close to the origin of Climacograptus sensu stricto.

6.b. Ordovician trilobites (WTD)

Morphological terms are essentially those used in the first edition of the Treatise on Invertebrate Paleontology (Harrington et al. in Moore, 1959) with modifications proposed for the second edition by W hittington & Kelly (1997). N otation for the trinucleid pitted cephalic fringe is basically that proposed by W hittard (1955), with modifications by Ingham (1970) and Hughes, Ingham & Addison (1975).

6. b. 1. Trilobites from the Karadere Formation

All the material was obtained from four thin (< 1 cm) fossiliferous layers (Figs 5, 6; FOB-4/FOB-11, FOB-12 /OFB-9, FOB-13, FOB-14) within an estimated thickness of about 2 m at the roadside section southeast of Zirze. Specimens are preserved as internal and external moulds in brown-weathering, grey, fissile mudstone.

Family SHUMARDIIDAE Lake, 1907 Genus Leioshumardia W hittington, 1965

Leioshumardia sp. nov.(Fig. 14i,j,l,m)

Figured specimens. NM W 95.34G.1 and 4, from OFB-9; NM W 95.34G.2 and 3 from FOB-12 (same level). Questionably at FOB-13.

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LithostratigraphyBase -

KARADERE FORMATION►Top

Localities

Speciesoccurrence

O = A bundant (m ore than 10 specim ens)

FOB 5, O

FB-3OFB

2, OFB-5

FOB 6, O

FB-4O

FB-7Not seen

FOB-7

FOB

-8/OFB

-8Not seenFO

B-12/ O

FB-9FO

B-13

FOB

-14O

FB-10

Not seen FOB-30

FOB-31

Not seen FOB-33

FOB-15 / OFB-11, FO

B-34

Azygograptus cf. eivionicus Elies & Wood ❖Pseudophyllograptus a. angustifolius (Haii) ©

Isograptus caduceus imitatus Harris *D. (Corymbograptus) cf. deflexus (Elies & Wood) ❖

Acrograptus gracilis Törnquist ❖

Didymograptus nitidus (Haii) * © * ❖ (2fi) ❖ * *

Tetragraptus bigsbyi (Haii) ❖ © © © ❖

D. (Didymograptellus) protobifidus Elies

Sigmagraptus sp. © ©

Pseudisograptus manubriatus koi Cooper & Ni ❖

D. (Didymograptellus) minutus Törnquist ❖

Tetragraptus quadribrachiatus (Haii) ❖

Undulograptus? mui sp. nov. ©

Oelandograptus austrodentus (Harris & Keble) ❖

Aulograptus cucullus (Bulman) ❖

A? aff .feistmanteUi Boucek ❖ ❖

Prolasiograptus haplus praecursor subsp. nov. ❖

Oelandograptus oelandicus (Bulman) ❖

Eoglyptograptus bouceki sp. nov. ❖ * ❖

Didymograptus? uniformis lepidus Ni © ❖

Crypto graptus sp. ©

D. (Corymbograptus) vfractus volucer Nicholson ❖

D. (Didymograptus) artus Elies & Wood ❖ ❖

Eoglyptograptus jaroslavi (Boucek) ❖

Climacograptus angustatus Ekström *

D. (Didymograptus) spinulosus Perner ®

D. (Didymograptus) pseudogeminus Boucek

Species transitionLLANVIRNoccurrence

^ ^ - -^ ^ C h ro n o stratigraphyARENIG SERIES SERIES (part)


g J OU RN A LS I




Description and discussion. The type species, L. minima Whittington (1965, p. 331, pi. 17, figs 9, 10, 13, 15-17) from the Middle Table Head Formation (approximately early Llanvirn) of western Newfoundland, is readily distinguished from the Turkish form by its narrow (sag.), incised occipital furrow (SO), and by the subpentagonal glabellar outline, which narrows at SO and then expands to the plumply rounded sides. Much closer comparison can be made with Leioshumardia sp. A of Fortey & Owens (1987, p. 126, fig. 181) from the middle Arenig of south Wales. Both have a glabellar outline that is subtriangular, with small anterolateral breaks in outline, the occipital furrow is almost obsolete, and the pointed front of the glabella merges with a small, shallow depression separating it from the cranidial margin. However, the glabella of the Turkish species has the axial furrows less convergent than those of the Welsh form (approximately 35° compared with about 45°), the length:breadth ratio of the glabella is about 1.3:1 compared with 1:1, and as far as can be judged the pleuroccipital furrow is more distinct.

Family DIONIDIDAE Gürich, 1907 Genus DionideUa Prantl & Pfibyl, 1949

Dionidella? sp.(Fig. 14h,n)

Figured specimens. NM W 95.34G.5 and 6, both fromFOB-12.

Description and discussion. An incomplete cranidium of dionidid type (Fig. 14h) with estimated width of 9.5 mm is bluntly rounded frontally, and about 2.5 times as broad as long. The anterior and lateral margins are circumscribed on the ventral surface by a narrow rim, seen here as an external mould, that widens posterolaterally towards the incomplete right librigenal spine. Length of the glabella about 0.7 (est.) that of the cephalon, and although the basal lobes are not clearly defined, the maximum breadth is about twice that (tr.) across the incomplete occipital ring, which is very small and much narrower (sag) than the long (tr.), transversely straight posterior border and deep border furrow. Anterolateral surface of the preglabellar area and the adjacent gena carries traces of pits similar to those seen on corresponding parts of the type species, DionideUa incisa Prantl & Pribyl (1949, pi. 1, fig. 1) from the Llanvirn of Bohemia, illustrated more clearly by Hornÿ & Bastí (1970, pi. 13, fig. 1). Remains of three thoracic segments, the first slightly macropleural, generally resemble those of D. incisa and also those of Dione formosa Barrande, 1846, p. 33, type species of Dionide Barrande, 1847, from the Caradoc of Bohemia and redescribed by Whittington (1952, p. 6, pi. 1, figs 1, 2, 5; text-fig. 1). The fact that the basal glabellar lobes are clearly in front of the posterior border furrow suggests that the species belongs to DionideUa rather than Dionide, and some comparison may be made with DionidellcP sp. indet. 1 of Fortey & Owens (1987, p. 222, figs 85a,b), from the late Arenig of south Wales, which has a similarly short (sag.) cranidium and transversely straight posterior border and furrow. One example of the Welsh form (Fortey & Owens, 1987, fig. 85b) shows what appear to be coarse granules that may represent infillings of anastomosing ridges on the upper surface, but further comparison is impracticable.

A fragment of pygidium apparently enrolled beneath a cranidium of DionidellcP. sp. (Fig. 14n) shows little detail, but the axis is broadly similar to that D. incisa and has at least eight small transversely straight axial rings and a diminutive terminal piece close to the rounded posterior margin.

Family t r in u c l e id a e Hawle & Corda, 1847 Subfamily t r in e t c l e in a e Hawle & Corda, 1847

Genus Bergamia W hittard, 1955

Bergamia cf. rushtoni Fortey & Owens, 1987 (Fig. 14a-g)

cf. 1987 Bergamia rushtoni Fortey & Owens, p. 205, figs 72a-k.

Figured specimens. NM W 95.34G.7 to 13, from FOB- 12/OFB-9 (same level) and FOB-14. Occurs also at FOB-13.

Description. O f the seven available trinucleid specimens showing part of the cephalic fringe, all but one are from a single level (FOB-12/OFB-9). The smallest (Fig. 14e) is about 3.5 mm (est.) wide; the large alar lobes are clearly visible; and the genal prolongation is set well forward of the posterior furrow. The estimated fringe formula is: Ej 2 or 3-14, E, 1-14; I arcs cannot be distinguished with certainty. A slightly larger cephalon (Fig. 14c), 4 mm wide (est.), is too incomplete for fringe pits to be counted but shows traces of alar lobes; the slightly disarticulated thorax has four segments and the pygidium, of typical trinucleine type, has possibly two axial rings and two pairs of pleural ribs. The original of Figure 14a has a cephalic breadth of 5 mm (est.) and lacks most of the glabella and cheek lobes; the incomplete external mould of the ventral fringe lamella shows the following estimated pit count: Ej 1-16, E, 1-16 (right half); at least one I arc (In) is developed frontally. The specimen in Figure 14b, with six thoracic segments, has a cephalic breadth of 6 mm (est.), and the pygidium, with bevelled marginal rim, has an estimated three axial rings and three pleural ribs. The incomplete cephalic fringe shows only that Ej is developed from R l, and E, from R4. Figure 14g also has a cephalic width of 6 mm (estimate based on right half) and coarse, reticulate ridges on both glabella and cheek-lobe. The fringe shows three or four arcs of pits set in deep radial sulci that are widely spaced as far as R4, beyond which the interradial areas are veiy narrow, a variation seen partially in Figure 14a. Estimated fringe formula: Ej 1-17, E, 1-18; In is visible from about R3, and there is a suggestion of Ij anterolaterally.

Figure 14d shows the ventral lamella juxtaposed with the remainder of an exoskeleton that lacks pygidium and fringe; coarse, reticulate ridges seen here on both glabella and genae are less obvious in other specimens. Overall breadth across the fringe is 7 mm (est.) and the girder is strongly developed, especially frontally. Ej_, from R l to R17 (est.) in each half, their pits set in deep radial sulci that become slightly more closely spaced anterolaterally; a few large pits (Ij or In) are developed medially behind the girder. The largest available specimen (Fig. 14f) lacks the cephalic fringe and the thorax is about 10 mm(est.) wide.

Figure 13. List of graptolites from the Karadere Formation. Localities shown in Figures 3, 5-7. Key: * = occurs; A = abundant at FOB-15 and FOB-34; B = occurs at O FB-11 only; C = occurs at OFB-9 only; E = occurs at OFB-8 only; G = occurs at OFB-2 only; circle around asterisk or letter = > 10 specimens.

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5 7 6 W . T . D E A N A N D O T H E R S

Figure 14. For legend see lacing page.

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Discussion. Bergamia has an extended vertical range, from Arenig to Llandeilo, in the Anglo-Welsh portion of peri- Gondwana; elsewhere it is recorded from the early Llanvirn of Scania, Sweden (Owen, 1987, p. 94) and, questionably, from the ‘Middle Ordovician’ of eastern Pamir (Hughes, Ingham & Addison, 1975, p. 558). W hittard’s (1955, p. 31) generic diagnosis described the cephalic fringe as ‘typically bearing Ej , E, and I j , although there may be a duplication by twin-pits in I j , particularly the more axial radii; pits along ej and e, are of erratic occurrence, but always present in mid-line’. The fringe formula of the type species, B. rhodesi Whittard (1955, p. 32, pi. 3, figs 8-13) from the late Arenig of the Shelve Inlier, Shropshire, is: Ej 1-19, E, 1-18; e^ , 0, i, iv; Ij 1-15 [L 1-5]. The generic diagnosis was modified slightly by Hughes et cd. (1975, p. 558) to include, inter cdia, the following: ‘Fringe narrow, ....Ej complete, E, variably developed set veiy close to Ej. In complete, other arcs variably developed. Pits on both lamellae in deep radial sulci with only a small number of irregularly arranged pits laterally in the centre of the genal prolongations’ (In was introduced by Ingham, 1970, p. 40, for the innermost arc and corresponds, apparently, to W hittard’s Ij). The Turkish specimens meet the criteria for Bergamia, though the pit-count is less than that for B. rhodesi, and they have much in common with B. rush toni from the late Arenig of south Wales. Among diagnostic characters of the latter species Fortey & Owens (1987, p. 205) listed ‘typically 15 or 16 (rarely 18) pits per half-arc, in deep radial sulci in adult specimens’, and ‘radii widely spaced in front of glabella’, with interradial areas considerably wider than radii frontally, but narrower posterolaterally. The latter feature is seen clearly in Figure 14g, and less so in Figure 14a,d, while the pit count for Ej_, in the Turkish sample falls within the range for the type material, though E, may be complete frontally, rather than commencing ‘normally atR 2 o rR 3 ’.

Family c y c l o p y g id a e Raymond, 1925 Subfamily c y c l o p y g in a e Raymond, 1925

Genus Cyclopyge Hawle & Corda, 1847

Cyclopyge sp.(Fig. 14k)

Figured specimen. NM W 95.34G.14, fromFOB-12.

Description and discussion. Cyclopygids are veiy rare at Zirze. One poorly preserved external mould of a pygidium (estimated breadth c. 2.5 mm) with part of, possibly, two attached thoracic segments has a long triangular axis that occupies about two-thirds of the median length. There is evi

dence of three axial rings, followed by a small, pointed terminal piece; and the pleural fields carry traces of two, possibly three, pairs of ribs. The general configuration resembles that of Cyclopyge kossleri (Kloucek, 1916), from the Sárka Formation (Llanvirn) of Bohemia, redescribed by Marek (1961, p. 25, pi. 1, figs 14-17; text-fig 7), rather than the type species Cyclopyge rediviva (Barrande, 1846) from the Caradoc of Bohemia, redescribed by M arek (1961, p. 19, pi. 1, figs 1-6; text-fig. 4), and other forms in which the pygidial axis is short, only slightly tapered, and has a bluntly rounded tip. An incomplete dorsal exoskeleton from the early Llanvirn of south Wales was assigned to C. kossleri by Fortey & Owens (1987, p. 155, figs 37a, b).

Family a l s a t a s p id id a e Turner, 1940 Genus Seleneceme Clark, 1924

Seleneceme acuticaudata (Hicks, 1875)(Fig. 14o-r)

1875 IUaenopsis?acuticaudataHicks, p. 184, pi. 9, fig. 5. 1960 Seleneceme acuticaudata (Hicks); W hittard, p. 118,

pi. 16, figs 1-5. Includes synonymy.1987 Seleneceme acuticaudata (Hicks, 1875); Fortey &

Owens, p. 230, fig. 91.1989 Seleneceme acuticaudata (Hicks, 1875); Kennedy,

p. 34, pi. 8, figs 3, 9,10.

Figured specimens. NM W 95.34G.15a, b to 17, from FO B -11 and FOB-12. Questionably present at FOB-13.

Description and discussion. Hicks’s holotype came from the early Llanvirn (artus Biozone) of Llanvirn Quarry, southwest Wales, and the species occurs at the same level in the Shelve inlier of west Shropshire (Whittard, 1960, p. 120). In the W hitland area of south Wales, the species occurs in both the latest Arenig and the early Llanvirn (Fortey & Owens, 1987, pp. 86, 230). W hittard’s detailed description includes (1960, pi. 16, fig. 2) an almost complete exoskeleton which matches closely the cephalon in Figure 14o,r, with its median glabellar tubercle and characteristically widely divergent pleuroccipital furrow, and differs only in having the librigenal spines less strongly splayed. None of W hittard’s specimens from Shelve included the pygidium but he recorded at least 28 conjoined segments without finding undoubted evidence of the complete thorax. Two specimens from Zirze (Fig. 14p,q) show, respectively, 12 and 10 thoracic segments, the first one macropleural, similar to those illustrated by W hittard (1960, pi. 16, see especially figs 1,3,4).

Figure 14. (a-s) Karadere Formation; (u-w, y-z') Ketencikdere Formation, Limestone Member; (t, x) Ketencikdere Formation, Siltstone Member, (a-g) Bergamia cf. rushtoni Fortey & Owens, (a) NM W 95.34G.7, x 8, FOB-12; (b) NM W 95.34G.8, x 4, FOB-12; (c) NM W 95.34G.9, x 8, FOB-12; (d) NM W 95.34G.10, x 3, OFB-9; (e) NM W 95.34G.11, x 8, FOB-12; (f) NMW 95.34G.12, x 2.5, FOB-14; (g) NM W 34G.13, x 8, FOB-12, (h, n) DionidellcP sp., FOB-12, (h) NM W 95.34G.5, x 4; (n) NMW 95.34G.6, x 8. (i, j, 1, m) Leioshumardia sp. nov.; (i) NM W 95.34G.1, x 10, OFB-9; (j) NM W 95.34G.2, x 10, FOB-12; (1) NMW 95.34G.3, x 10, FOB-12; (m) NM W 95.34G.4, x 10, OFB-9. (k) Cyclopyge sp. NM W 95.34G.14, x 6, FOB-12, (o-r) Seleneceme acuticaudata (Hicks), (o, r) counterparts, NM W 95.34G.15a, b, x 4, FOB-12; (p) NM W 95.34G.16, x 2.5, FOB-12; (q) NMW 95.34G.17, x 2.5, FOB-11, (s) bedding-plane with specimens in (b), (c), (e) and (h), x 2, FO B -12. (t) Genus and species undetermined, incomplete pygidium, NM W 95.34G.22, x 2.5, OFB-25. (u) Raphiophorid genus and species undetermined, incomplete pygidium, NM W 95.34G.19, x 2.5, FOB-35, (v) Trinucleid? genus and species undetermined, cranidium, NM W 95.34G.20, x 4, FOB-37, (w) Ampyx sp., latex cast of cranidium, NM W 95 34G.18, x 4, FOB-35, (x) Prionochelius sp., internal moulds of two cranidia, NM W 95.34G.23 and 24, x 2, FOB-16, (y, z, z') RemopleurelkP. sp. (y, z) internal mould of cranidium, (z') latex cast of same specimen. NM W 95.34G.21a, b, x 2.5, FOB-36. Scale bars = 1 mm(e, i, j, 1, m, n), 1.5 mm (a, c, g), 2 m m (k), 3 m m (b, h, o, r, v, w), 4 mm (d, f, p, q, t, u, y, z, z') and 5 mm (s, x).

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6.b.2. Trilobites from the Limestone Member o f the Ketencikdere Formation.

All but one of the figured specimens are from the stratotype section by the east side of the track along the east bank of the Ketencik Dere valley (Figs 3, 7), 2.5 km south-southwest of Zirze. The remaining specimen (Fig. 14t) is from the parastratotype section, near the north end of Akçayazi Dere and 1.5 km southeast of Zirze (Figs 3, 5, 8). The age, based on the conodonts, is probably early Caradoc, and this agrees broadly with the sparse evidence of the trilobites. Additional material too fragmentary or too poorly preserved for illustration or description includes both undetermined illaenids (FOB-35, 7FOB-36), and undetermined genera and species (FOB-37, FOB-38, OFB-25).

Family r a p h io p h o r id a e Angelin, 1854 Genus Am pyx Dalman, 1827

Am pyx sp.(Fig. 14w)

Figured specimen. NM W 95.34G.18, from FOB-35, Ketencik Dere.

Description and discussion. A fragment of cranidium, figured as a latex cast, shows the posterior half of the glabella and part of the genae. It is generally comparable with the type species, Am pyx nasutus Dalman, 1827 from the late Arenig of Sweden, redescribed by Whittington (1950, p. 554, pi. 74, figs 3-9; text-fig. 6A, B), and has similar, paired glabellar muscle scars, but more strongly divergent axial furrows.

An associated, undetermined pygidium of raphiophorid type (NM W 95.34G.19, Fig. 14u) has almost flat pleural lobes and a thin marginal rim. There are eight pairs of pleural furrows and the first three, possibly four, ribs cany straight rib furrows. The gently tapered, straight-sided axis has seven rings, the incised ring furrows of which show apodemal pits on the internal mould, and a diminutive terminal piece that touches the rim. The deep, straight pleural furrows exclude the specimen not only from Ampyx and Lonchodomas (redescribed by W hittington, 1950, p. 556) but also from Ampyxina, in which they turn strongly backwards distally. Better comparison may be made with the type species of Ampyxoides Whittington (1965, p. 319), A. semicostatus (Billings, 1865), from the Llanvirn of western Newfoundland, which has a marginal rim and nearly straight pleural furrows, but more Turkish material is needed.

Family t r in u c l e id a e Hawle & Corda, 1847Trinucleid? genus and species undetermined

(Fig. 14v)


Description and discussion. A slightly distorted, incomplete cranidium about 10 mm wide and 5 mm long (est.) is strongly convex longitudinally and transversely, and lacks the cephalic fringe. The bulbous glabella occupies about 0.3 the overall breadth and is almost in-line frontally with large, convex, quadrant-shaped genae that are incomplete but retain traces of a mesh-like pattern of anastomosing ridges. There is a poorly preserved median node behind centre of the glabella, which carries traces of anastomosing ridges; alae are probably absent, but the relevant area is incomplete.

Family r e m o p l e e t r id id a e Hawle & Corda, 1847Genus Remopleurella Dean, 1963

RemopleureUal sp.(Fig. 14y,z,z')


Description and discussion. An incomplete, almost undeformed cranidium in dark-grey, fine-grained limestone has a breadth of 11 mm (est.), and the middle portion (excluding anterior glabellar tongue and occipital ring) is about as broad as long, and of low convexity. The parallel-sided glabellar tongue turns down through a right-angle and its median breadth is about 37% that of the cranidium; the transversely straight frontal margin shows part of a diminutive, rim-like anterior border. The exoskeleton is thin, covered with veiy low, thin, anastomosing ridges and has three pairs of lateral glabellar furrows; Si is exaggerated by crushing and S2-3 are almost indiscernible, smooth lines. The lectotype of Remopleurides kullsbergensis Warburg, 1925, from the early Caradoc of Sweden, redescribed by Nikolaisen (1982, p. 241, pi. 2, figs 7, 8), shows similar S1-3 and surface ornamentation, and the anterior tongue is of similar width, but the overall convexity is greater. The type species of Remopleurella, R. burmeisteri Bancroft, 1949, from the latest Caradoc of Shropshire, redescribed by Dean (1963, p. 250) and, again, by Nikolaisen (1982, p. 289) using uncompressed Norwegian specimens preserved in limestone, has a similar form and convexity, but the anterior tongue expands forwards slightly and Si 3 are deeper. Scandinavian species of Sculptella and Sculptaspis (Nikolaisen, 1982, pp. 265-86) have a glabellar surface ranging from almost smooth to ridged like that of the Turkish specimen; the anterior tongue varies from wide to veiy narrow, and their notably larger anterior border is probably a more important diagnostic character.

Genus and species undetermined (Fig. 14t)

Figured specimen. NM W 95.34G.22, from OFB-25, near the north end of Akçayazi Dere.

Description and discussion. A single, incomplete pygidium, about 8 mm long (est.) excluding the articulating half-ring, is the only macrofossil found at the parastratotype of the Ketencikdere Formation. Due to lateral compression the specimen is slightly asymmetrical and the postaxial portion is missing, but the estimated length:breadth ratio is 3:4. The axis is slightly tapered, moderately declined, and occupies about 0.8 (est.) of the overall length; six transversely straight axial rings are visible, and the pleural regions cany five and a half pairs of unfurrowed ribs, with traces of a sixth; the latter are separated by pleural furrows that do not reach the margin and are deep and broad (exsag.) on the internal mould but shallow on what remains of the external surface, which carries possible traces of tubercles. The general aspect is that of a phacopacean or calymenacean, but the material is insufficient for detailed comparison.

6. b. 3. Trilobites from the Siltstone Member o f the Ketencikdere Formation

Specimens were found at only a single locality, FOB-16 (Figs 3, 5, 8), by the east side of the unpaved road at the north end of Akçayazi Dere and 1.5 km south-southeast of Zirze.

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Family b a t h y c h e il id a e Pribyl, 1953 Subfamily p h a r o s t o m a t in a e Flupé, 1953

Genus Prionochelius Rouault, 1847 Prionochelius sp.

(Fig. 14x)

Figured specimen. NM W 95.34G.23 and 24.

Description and discussion. Two juxtaposed, incomplete cranidia, both of them compressed and slightly deformed, with a smaller, associated fragment, show the characteristic, well developed anterior border and distinct, though narrow (sag.) preglabellar field; the glabellar outline is ‘stepped’ at S2 and lacks clear evidence of S3. The palpebral lobe is approximately opposite L2, and the width of the preocular fixigena is about 50% (est.) that of the glabella at S2. There are traces of a narrow paraglabellar area opposite L 1 and, in one case, of a fixige- nal spine. The poorly preserved surface of the exoskeleton is coarsely granulate. Prionochelius has a long stratigraphie range, from Arenig to Ashgill, mostly in peri-Gondwanaland, especially Europe and the Mediterranean region, but extends north into the Caradoc and Ashgill of Baltica, and east into the middle Ordovician of southwestern China.

Acknowledgements. Fieldwork in the Pontides by Dean, M onod and the late Francine M artin was carried out thanks to the logistical support of Turkish Petroleum Corporation (T.P.A.O.), who also permitted publication of the results and certain of the Corporation’s unpublished maps. M onod acknowledges support from C.N.R.S. (UM R 6530) and thanks M. Robardet for fruitful palaeogeographic discussion. Dean thanks the Leverhulme Trust for the award of an Emeritus Fellowship, and Robert M. Owens for reading the manuscript. Text-figures were prepared by Mme Nathalie Laurent-Rouchon (Université d ’Orléans) and Mrs Lin N orton (National Museum of Wales, Cardiff); photographs of trilobites were taken by Mrs Kathi Bryant (National Museum of Wales).

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lower palaeozoic stratigraphy and palaeontology, karadere ...recorded in the istanbul area...

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