ABT. 7 NEW FOSSIL REPTILE — GILMORE 7 



swollen transversely are a combination of characters in which 

 Hypsognathus seems to show cotylosaiirian affinities. On the other 

 hand, as Dr. E. C. Case has pointed out to me, the relatively narrow 

 and high neural arches of the vertebrae seem to be opposed to such a 

 relationship. After an examination of a cast of the type specimen he 

 says : 



The neural arches of all cotylosaurs are low and very broad ; this is high. 

 I know of no exception to this rule, low broad neural arches in the Cotylosauria. 

 Broili's Solenodonsaurus is reported by him to have narrow neural arches, but 

 others who have seen the specimen say this is obviously due to compression. 



Perusal of the literature shows the above generalizations to be cor- 

 rect, though it seems to me they do not fully apply to certain of the 

 cotylosaurians from the European Triassic described by Huene.^ 

 Reference is made to the vertebrae of Koiloskioscmrus, which appears 

 to have a neural arch equally as high and narrow as the vertebrae of 

 Hypsognatlius. The spinous processes are likewise of nearly equal 

 height. Furthermore, the lower jaw of Kiolosk'iosaurus in its con- 

 siderable height with receding anterior end, and rapidly reducing 

 height of the end posterior to the coronoid processes are features held 

 in common with the mandible of Hypsognathus. If correct in my 

 identification of a portion of a limb bone as being the proximal end of 

 the humerus, this end is shown to be much expanded as in other coty- 

 losaurian reptiles. The few metapodials preserved are also in accord 

 with such relationships. While the evidence thus briefly reviewed is 

 insufficient to certainly determine the affinities of the present speci- 

 men to lie within the Cotylosauria, it nevertheless strongly suggests 

 such relationship. 



Of the few known elements of the Upper Triassic fauna of North 

 America Stegomosuchus longipes (Emerson and Loomis) is the 

 only form that need be compared with the present specimen. The 

 larger size of Hypsognathus, the absence of dermal armor, the deeper 

 heavier mandible, and the short and stout metapodials are a group 

 of features that seem quite sufficient to show its distinctness from 

 that species. In size and general proportions it closely approxi- 

 mates KoilosMosaurus cohurgiensis Huene, and in general appear- 

 ance it would probably not be greatly unlike Huene's restoration 

 of that animal. 



On account of the several resemblances to certain Triassic coty- 

 losaurians discussed above I propose to provisionally refer Hypsog- 

 nathus fenneri to the Order Cotylosauria in the hope that the 

 discovery of better preserved and more diagnostic specimens will 

 either confirm this tentative reference or reveal its true rela- 

 tionships. 



*Die Cotylosauria dcr Trias, ralaeoatolo.^raphica, vol. 59, 1912, pp. 69 to lOli. 



