Abraham MirandaCSUSB3.5.09

Barrel bodiedSmall headsOriginally lumped together, the subclass

Edaphosauria includeEdaphosauridaeCaseaLupeosauridaeNitrosauridae

Romer appeared to have decided Edaphosaurus should have their own subclass, but he was overruled

Romer compared the Edaphosaurus to Casea because of their pelycosaur similarities

Projection off the frontal bone, creating a large lappet

Quadratojugal not connected to the subtemporal bar

Lacrimal bone reaches from the orbits to the naris

A narrow skull tableHave a supraorbial

brow or shelf created from the prefrontal, frontal and post frontal bones

Postorbital process reduced

No connection with the postorbital bone and supratemporal bone

Temporal bar is created from the jugal and squamosal bones

Quadratojugal jugal is reduced

Supraoccipital is smaller compared to sphenacodonts

Articulation of the jaw joint is below the rows of teeth

Dentary bone has a big coronid process

The prearticular bone is rotated to fit under the pterygoid process of articular bone

All marginal teeth slightly enlarged at distal portions

Sail: Formed by the neuro spinous processes of the cervical, thoracic, and lumbar vertebrae

Neural spines are circular at distal endsNeural spines are laterally compressed at

proximal ends Cervical neural spines bend anteriolyPosterior neural spines bend posteriorlyNeural spine tubercles paired at the proximal

ends

Neural spines enlongated on presacral bonesShort transverse tubercles

Distal neural spines loose dual cylinder structureStolen from Adam Huttenlocker

Limbs are shortAll Edaphosaurs have a curve to ribsTubercular head of ribs are small ridged

KANSAS

Oldest and most primitive of the EdaphosauridaeTwo well-preserved specimens found in Garnett, KansasFirst found in the Upper Pennsylvanian Rock Lake Shale

of the Stanton formation.A stream valley in which there was a slow transgression

of flood waters.First unearthed by P.E. Peabody in 1957, and thought to

be a Dimetrodon, Reisz in 1982 confirmed this unknown specimen as an edaphosaur

Maintained edaphosaur spines, but did not really fit in with the rest of the genus, so a new genus was erected: Ianthasaurus

Only known species of Ianthasaurus: Ianthasaurus hardestii

Insectivore

Pre and Postfrontal bones articulate to the Parietal

Reduced quadratojugal from the temporal bar

Small temporal fenestra

Long and low maxilla

27-29 teethEnlongate maxillaCaniniform teethSharp and recurved

posteriorly dentitionHomodont dentitionNo toothplates Palatine teeth infer

insectivory

Centrum lengths of the Cervical vertebrae are greated than the rest of the presacral vertebrae

Neural spines running of the cervical vertebrae are thicker and more robust

Transverse processes of the vertebrae are short

Ribs are not strongly curved like the rest of the edaphosaurs

Longest neural spine is at vertebrae 17

29 Presacral vertebrae

Lack tubercles on the neural spines

Neural spine sail is the smallest of the Edaphosauridae

No more than 5 tubercles on neural spines

27 Neural spines in the sail No central elements in all neural spines Neural spines lean forward in cervical

region and rearward in the lumbar region

Neural spines begin at third cervical vertebrae on down to the second to last lumbar vertebrae

Measurements of the centra impossible to crush and bad preparation

Proximal portions of the neural spines are laterally compressed

Neural spines are subcircular at the basal tubercle

Considered a tool for heat exchange over a sexual dimorphism or “solar collector”

Right scapulocorocoid

Left pelvisPartial manus Left humerous Only 2 usable

Ianthasaurus have been recovered

Medial view: the scapular and anterior corocoid is exposed.

Posterior corocoid is unavalible Scapula and corocoid are

separated by nature or by degradation along suture contact

Gleniod is too poorly preserved Supragleniod foramen exist? At the anterior margin of

scapular blade, a notch is seen in many pelcosaurs

Function? Anterior corocoid expanded

dorsoventrally and with a convex shape.

Function?

Humerus badly preserved and featureless

Distal end of humerous is narrow and no supinator process seen

Diaphysis is almost perfectly round in cross section

No evidence of the epiphyses being twisted about the bone

Identified as the ulnare, intermedium medial and lateral centrale

Nothing can be offered, not enough.

Illuim is well-developed with a blade-like processes extending posteriorly

The anterodorsal process is smaller than the posteriordorsal process

Ribs are slighly curved with a smooth tubercular bump

Complete ilium has been found Pubis and ischium have been

lost Iliac blade is extended

posteriorly like other primitive pelycosaurs

Obturator foramen on posterior edge , but posterior boarder is opened

Indicates that this specimen is immature

Ischium retains the structure of other early pelycosaurs

Pubis and ischium are narrowly connected below the acetabulum

Lived in the Lower Permian of North-Central Texas

Represented by a single skullShares 5 synapomorphies with Edaphosaurs

What is G?G= 5 reasons

Transverse flange of pterygiod is missing

The prefrontal bone ventral process is transversly expanded

No caniniform teethNo caniniform regionPremaxillary and maxillary teeth identical

8 species currently recognized

EdaphosaurusE. boanergesE. cruciger- largest

sailE. pogoniasE. novomexicanusE. colohistionE. credneriE. raymondi

Most species are described by 1 or 2 badly preserved skulls

Many specimens found in the Geraldine Bonebed in Archer County, Texas

Larger barrel shaped body over Ianthasaurus

Dozens of specimens found in North-Central Texas

Many complete skulls

No so many complete skeletons

Used as the model for all Edaphosaurs

Reduced skull sizeHead is the size of 5

dorsal centraNot as enlongate as the

IanthasaurusProcess of the postorbital

is short, not extending to the parietal foramen

Nasal bone is ¾ the size of the frontal

Subtemporal bar is displaced superiorly

Temporal fenestra is enlarged anteriorly and posteriorly

Supraorbital shelf is wide and deep concealing the orbits

Lacrimal bone is thin at the maxillae and progressively thickens posteriorly suggesting it carries some kind of load and transfers it to the prefrontal

Prefrontal and lacrimal form a buttress attachment for reinforcement

The nasal bone has a “scarred shelf” and sutures that lock into the prefrontal bone as well as thicken around the orbit.

Suggests that carries load for feeding

Premaxilla is enlongated in cross section

Premaxilla has 5 teeth, but none have survived to determine dimensions

The maxilla accomodates

18-21 teeth No Caniniform teethNo Caniniform regionNo pterygiod flangeAll Homodont/isodonty

dentition

Jaw is suspended way below the upper tooth row

Well developed tooth plates on palate and mandible

Densely packet teethTooth plates form on the

palate and inner aspect of the mandible

Palatal plate consists of the pterygoid ectopterygiod, and palatine

Mandibular tooth plate is formed by the coroniod, posterior coroniod, and prearticular bones

Denticulated plate is formed by the ant coroniod, coroniod and prearticular bones

120-150 teeth per palatal bone plate

Maxilla bone is twisted out laterally

Dentary bone is twisted in medially

Purpose?

Massive tooth plate found on the mandible, bigger than on the maxilla/palate

Deeply cut through mandibular symphysis

Jaw articulation denoted propalinal or front to back movement of jaws

Maxillary teeth progressively angle backwards as you go to the dentary bone

Reduced homodont dentition

Isodonty in the marginal teeth cropped plant matter

Teeth are distally swollen

Fine serrated tips curving backwards

Palatal and mandibular tooth plates served as primary grinders of plant matter

Posterior maxillae and dentary teeth assisted with minor grinding

Supraoccipital has little lateral exposure

Tabular bones are thick towards the parietal, but they are thin and suture into paraocciptal bones

Postorbital is a slender sigmiodal bone.

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Cervical vertebrae are extremely short compared to the dorsal and lumbar vertebrae

Ianthasaurus has longer centra on their cervical vertebrae

Contain neural spines that are enlongated with longitudinal ridges at the sides of the spines

Anterior to mid dorsal neural spines are tall and pointed. E. boanerges has the second longest neural spines

Neural spines are tall and pointed with a slight posterior angulations

Multiple lateral tubercules that are arranged laterally across the neural spines

Neural spine tips of sacral and caudal vertebrae are roughened or crenulated like a castle

They have longitudianal ridges that are rough Anterior view w/ R rib

Ventrally hypertropied clavicle

A heavy scapular blade

A reinforced or

Butressed supragleniod fossa

Increased coracoid processes

Anterior neural spines neural spines lean forward, lean posteriorly towards lumbar neural spines.

Dorsal ribs are strongly curved to the midlineTuberculae are well developed and slightly

roughened

Ilium: anterodorsal process are in equal size of the posterodorsal process.

First fragments recovered by P.E. Raymond in Pitcairn,Pennsylvania in 1908

Romer and Price wanted to keep this sample as E. mirabilis, but renamed it due to geopgraphic incompatibilies (1940)

Permian sample Only small spine fragment with some

tubercles found

12mm longOval in cross-sectionAnterior and

posterior sides cannot be dicerned

Little of lateral tubercle survives

Unknown mature sample

Declared a novum vanum

Early Permian pelycosaur found in the Wichita deposits of Texas

First thought by Romer or intermediate betweeen Edaphosaurus and Dimetrodon

Lack of cranial fossilsLack of Ianthasaurus-like shoulder girdle,

nothing to compare it to.

Only 3 survivedCentrum is 30mm longHave a mid ventral keelThe centra have a

diamond shape when cut transversly

This aspect is considered to be conserved through out the vertebral column

Anterior and posterior articular faces have “heavy lips”

Transverse processes are nearly identical to Edaphosaurus

Sacral vertebrae have been recovered , but the number is unknown

Considered robust and shorter, but the anterolateral aspect is dominated by the articulation to the ribs

• NO tubercles• Elevated transverse processes across the vertebral column• Zygapophyses are elevated•The centrum have a projecting keel

Lacked trabecular crossbars in neural spines

Mid-Dorsal Neural spine end missing

Neural spines have a forward tilt of 20 degrees at the base

Neural spines appear triangular at the base

8 spines have been recovered, considered to belong to the cervical vertebrae

Tall and narrow, no lateral depressions or modifications

Subcircular in cross-section

Mid Dorsal neural spines extend vertically , or almost perpendicular to level of the vertebral column

Posteriodorsal neuro spinous processes lean posterior of the animal

Maintain a similar orientation to that of Ianthasaurus

Expanded ventral aspect

Slightly bigger than the range of the edaphosaur clavicle

Anteromedial aspect is thick but the anterodorsal aspect is missing. Maybe some of clavicle is missing!

Dorsal edge of scapula preserved

Scapula blade could be larger and longer than any previous recorded pelycosaur!

Probably smooth surfaced

Contains a broad convex fossa on medial side for large subcorocoid muscle

Supragleniod contains lots of bone

Gleniod fossa is marginally preserved, hard to analyze

An enlarged sail seems to be primitive, with advanced organisms down regulating the sail size.

Conversion from omnivorous to plant eater with advancing species

Edaphosaurs and Ianthasaurs clearly vary Look for key features Caniniform vs non-caniniform Prefrontal transverse process Smooth or roughened neural spines

Glaucosaurs: an interesting intermediateLupeosaurs are tenative edaphosaurs, but their

vertebral and spinous process features confirm their standing as Edaphosaurs