Vol. 5, p. 179-181. December 18, 1925. 



Occasional Papers 



OF THE 



Boston Society of Natural History. 



ON THE REPRESENTATIVES OF THE SEYMOURIAMORPHA, 



SUPPOSED PRIMITIVE REPTILES, FROM THE UPPER 



PERMIAN OF RUSSIA, AND ON THEIR 



PHYLOGENETIC RELATIONS. 



BY PETER P. SUSHKIN 



(Member Russian Academy of Sciences; Honorary Fellow American Ornithologists' Union; 



Honorary Member British Ornithologists' Union). 



The genus Conodectes, more generally known as Seymouria, is 

 one of the most remarkable generalized types known and is 

 generally considered as the most primitive Reptile. Until quite 

 recently this genus, known only from the lowermost Permian of 

 Texas, stood alone. A short time ago (1923), however, Professor 

 Broili described a new genus, Solenodonsaurus, from the Upper 

 Carboniferous of Bohemia. And somewhat earlier, the late 

 Professor Amalitzki found some specimens which he recognized as 

 related to "Seymouria," in the Upper Permian of North Dvina, 

 Russia, and described them as Kotlassia. 



Having recently reexamined his material, I have found that 

 it contains two distinct genera. One of them, for which the 

 name Kotlassia is to be retained, is very similar to Conodectes, 

 since it possesses low spinous processes (text-fig. 1), a long pre- 

 sacral column of 26 vertebrae, and only one sacral vertebra. It 

 differs, however, from that genus by having a more depressed 

 skull (text-fig. 4, 5) , a larger post-temporal foramen, and more rudi- 

 mentary intercentra. The other differs from Conodectes by 

 having a short presacral column consisting of 18 vertebrae, by 

 possessing two sacrals, by its massive and long spinous processes, 

 which are knobbed at their tips (text-fig. 2, 3), and by having a 

 narrow, slitlike otic notch. I name this genus Karpinskiosaurus, 

 after Professor Karpinski, President of the Russian Academy of 

 Sciences, and consider it as the type of a new family, Karpinski- 

 osauridae. 



Thus the Seymouriamorpha were represented not only in 

 America, but also in Europe, where they survived till the close of 

 the Permian. 



In this material I succeeded, in both Kotlassia and Karpinski- 

 osaurus, in disclosing the stapes, which was hitherto unknown for 

 that group. This bone (text-fig. 4, 5) has the form of a rod, with 

 a slightly S-shaped bend, greatly thickened at its base and taper- 

 ing distally; the tip is connected with the distal end of the par- 

 occipital bar and terminates in a facet looking toward the otic 

 notch ; probably it had a connection with the tympanic membrane. 

 But there is no connection at all with the quadrate, and the tip of 

 the stapes lies far from that bone. 



