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30 



THE HISTORY OF THE PELYCOSAURIA, WITH 



Fam. Tectina/riali 



<ia. 



Genus Gorgonops Ow. Species O. torims Ow. 



In 1881 Owen 42 described a new genus, Mlurosaurus felinus, from South Africa, 

 which he considered as a member of the TheriodonUa, belonging to the " Mononarial 

 Section." The animal presents the elevated facial region of the Pelycosawria, with the 

 convex alveolar border of the upper jaw and the posterior position of the orbits. The 

 teeth are differentiated as in most all of the South African Reptiles. The posterior portion 

 of the cranium is lost and was later restored by Seeley 43 as an elevated region. There is 

 much more probability that it was depressed by the quick descent of the temporal bones 

 to join the depressed quadrate as in the American forms. Only the skull of the form is 

 known. 



In this paper Owen adds certain characters to the order TheriodonUa. He says: 

 " To the characters of this order given in my Catalogue of the Fossil RepUUa of South 

 Africa, viz., 'Dentition of the carnivorous type, incisors laniariform, canine on each side 

 of both upper and lower jaws,' may now be added 'dentition monophyodont.' Add to 

 these characters 'humerus perforated by an entepicondylar foramen.' " 



In 1889 Seeley 44 discussed the whole group Anomodontia and their relations to 

 the other Permian Reptiles. He says of the Pelycosauria, p. 282 : " There are few data 

 for judging of the systematic value of the Pelycosauria. But in view of the fact that 

 the Anomodontia was originally made to include animals which are allied to the Pelyco- 

 sauria, supposing that group to be well founded, it seems more; in accordance with usage 

 to class these animals with the Anomodontia than to adopt a new name like Theromorpha 

 for a well-known ordinal type. 



'There is need, however, that; the distinctness of the Pelycosamia should be estab- 

 lished. The tibiale and the centrale are said to unite! to form an astragalus which 

 has no movement on the tibia. One face of the astragalus receives the cuboid. 

 Subsequently an entire carpus was figured, which has a very mammalian aspect. It is 

 regarded as referable to Clepsydrops natalis Cope, and is classed as Pelycosauria. A 

 similar tarsus was subsequently referred with doubt to the genus Theropleura. It is dim- 

 cult to judge of its importance. Its characters appear to be more mammalian than those 

 of the Crocodilian tarsus, for the bones of the distal row an; completely ossified. The 

 tarsus is absolutely unknown in any of the Anomodontia from Africa, Europe and Asia • 

 and, therefore, there is no means of comparison with the American fossil. 



"The Pelycosauria are said to have two or three sacral vertebne, a notochonlal 

 column and intercentra usually present. With the evidence that Dinosaurs may have as 

 few as two sacral vertebrae, as well as a larger number than has been found in any Ano- 



