Skull elongate and compressed in front. Cleithrum small, tail elongate.
Limnoscelis Williston, United States.
Family Pantylidae (Pantylosauria). Terrestrial reptile less than two feet in length. Skull low, short, flat, with palatal and coronoid teeth; a single row of short teeth in [upper] jaws and mandible. Skeleton imperfectly known. No parietal foramen. Body covered with small bony scutes.
Pantylus Cope (? Ostodolepis Williston), United States.
2. Middle and Upper Permian
Family Pariasauridae (Pariasauria). Large lowland cotylosaurs reaching nine or more feet in length. Skull with protuberances, broad and short, its intimate structure not well known. Teeth in a single row, convex on the outer side with six or seven cusps arranged around their borders. Scapula with acromion and screw-shaped glenoid fossa. Phalangeal formula of front feet unknown. Astragalus and calcaneum fused; centrale and fifth tarsale unknown, possibly absent. Phalangeal formula believed to be 2, 3, 3, 4, 3 in one genus, primitive in others. Body with several rows of bony dermal scutes.
Pariasaurus Owen, Propappus Seeley, Anthodon Owen, Bradysaurus Watson, Embrithosaurus Watson, Pariasuchus Haughton and Broom, South Africa. Pariasaurus or an allied genus, Russia.
3. Lower and Middle Triassic
Family Procolophonidae (Procolophonia). Small reptiles a foot or more in length. Skull triangular, relatively smooth. Teeth in front conical, behind transverse, in a single row. Orbits very large, elongate anteroposteriorly. Parietal foramen large. Dermosupraoccipitals small or vestigial. Tabulars large, including between them and the squamosal a large otic notch. No supratemporals. Post-temporal openings of considerable size. Ectopterygoids distinct. Spines of vertebrae small. Two or three sacrals. Coracoids free in maturity. No cleithrum. Astragalus and calcaneum sometimes fused. Radiale and fifth carpale unossified, also centrale and fifth tarsale, so far as known. Lacrimals small, sometimes excluded from nares. Parasternals sometimes present.
