ANOMODONTIA. 



401 



The following genera with broad molar-like teeth have been united by 

 Seeley into a special order, the Oomphodontia : 



Tritylodon Owen, with transversely expanded molar-like teeth and a 

 pair of large incisors probably growing from persistent pulps ; with a 

 secondary palate and reduced quadrate ; very mammal-Uke, known by 

 skull only ; molars multituberculate. Diademodon Seeley, Triraehodon 

 Seeley, both with mviltituberculate teeth. Theriodesmus Seeley, known 

 by a remarkably mammaUan fore-limb and manus ; and other genera. 

 All the above are from S. Africa. Triglyphua Fraas, known only by its 

 molar-like teeth is from the U. Trias, Stuttgart. 



The following known from imperfect remains from the Permian of 

 Russia are probably Theriodontia ; Deuterosaurus Eichw., Rhopalodon 

 Fischer, with lanceolate molars and sclerotic ring. 



Fio. 222. — Cynognathus erateronotus, right side of skull with imperfect mandible (after Wood- 

 ward slightly restored). The molars possibly project further than m lUe and the crown 

 of the last is broken. d dentary ; j jugal ; Lt.f. small lateral temporal vacuity ; la 

 lacrymal ; mx maxilla ; na nasal ; orb orbit ; pa parietal ; pmx premaxilla ; prf prefrontal ; 

 pto postorbital ; ptf postfrontal ; st supratemporal ; sq squamosal. 



Order 3. Dicynodontia, 



Highly specialised land-forms, known by fragments from the Trias of 

 S. Africa, East India, the Urals, and Scotland. Tliere is a single temporal 

 arcade formed mainly by the squamosal which is very large and lies over 

 the small quadrate (Fig. 223). The jaws are edentxilous except for the 

 occasional presence of a pair of tusk-like teeth in the maxillae growing from 

 persistent pulps. There do not appear to be any secondary palatal plates 

 and the pterygoids are large, meeting in front of the basisphenoid. The 

 cervical ribs are double-headed, the dorsal single-headed ; the vertebral 

 column consists of 7 to 8 cervical, 12 to 13 dorsal, 6 to 6 fused sacral and 

 about 20 caudal vertebrae. Tliere appears to be a pineal foramen. The 

 scapula has an acromion, the pelvic bones are fused into an os innominatum. 



Dicynodon Owen, Oudenodon Owen, Ptychognathiis Owen, Karoo Sand- 

 stone of S. Africa. Gordonia and Geikia Newton, Elgin Sandstone 

 Scotland ; etc. 



Z.-II. 



D D 



