48 AMERICAN PERMIAN VERTEBRATES 



Family Seymouriidae 



Williston, Journal of Geology, XIX, 237, May, 1911. 



Skull triangular, depressed, tuberculate. A deep and narrow 

 otic notch in the temporal region. Teeth slender, conical, not 

 elongated in front. No cleithrum. Arches of presacral vertebrae 

 greatly expanded and with vestigial spines; ribs double-headed 

 throughout; a single sacral vertebra; tail short; no ventral ribs. 

 Legs short and stout; carpus and tarsus fully ossified; ungual 

 phalanges not dilated; tibiale and fibulare small. Digital fossa 

 extending to midway of femur, the adductor crest prominent. 

 Occipital condyle not flattened. An intertemporal bone in skull. 



SEYMOURIA 



Broili, Paleontographica, LI, 81, 1904; Desmospondylus Williston, Bull. Geol. 

 Soc. Amer., XXI, 280, 1910; Conodectes (?) Cope, Amer. Nat., XXX, 

 398, 1896; Proc. Amer. Phil. Soc., XXXV, 129, 1896. 



Seymouria baylorensis Broili, Paleontographica, loc. cit., PI. XIII, 

 ff. 1-3; Williston Jour, of Geol., XIX, 232, May, 1911. Pis. 

 XXVI-XXIX. 



Desmospondylus anomalus Williston, Bull. Geol. Soc. Amer., XXI, 280, 

 PL XVI. 



There are few Permian vertebrates of more interest than that 

 to which the name Seymouria baylorensis has been given. The 

 genus and species were originally described by Dr. Broili from two 

 imperfect skulls, a clavicular girdle and a few anterior vertebrae, 

 discovered on West Coffee Creek, in Baylor County, Texas, not 

 far from the town of Seymour. The characters, as given by Dr. 

 Broili, were most remarkable, almost incredible for a reptile, 

 including a deep otic notch, previously known only among amphib- 

 ians, and the presence of all the dermal temporal elements of the 

 skull known among the Stegocephala, that is the "epiotic," dermoc- 

 cipital, supra temporal, intertemporal, squamosal, and quadratoju- 

 gal. And there was nothing whatever in the specimen as described by 

 Broili to distinguish the creature from an amphibian, save the single 

 occipital condyle and the structure of the palate. These two type 



