56 



A REVISION OF THE COTYLOSAURIA OF NORTH AMERICA 



Genus PHANEROSAURUS H. v. Meyer. 

 Phanerosaurus naumanni, Paleontographica, i860, Bd. vn, pp. 248-252, Taf. xxvii. 



H. V. Meyer described a specimen consisting of four pos- — <C^^^ — .,.,^^ 



terior dorsals, the first sacral, and a fragment of the second 

 sacral, from the Rothliegende near Zwickau. 



The vertebrae figured by v. Meyer are typically Cotylo- 

 saurian. The neural arch is low and broad, with swollen sides 

 and short, stout neural spines. The centrum is much less in 

 width than the neural arches; a keel on the bottom line of the 

 centrum gives it a triangular section at the middle. There 

 are transverse processes on all the presacrals preserved, though 

 that on the last is very small. The anterior sacral vertebra is 

 not smaller than the last presacral and carries a large strong 

 rib. The second was smaller and was closely connected with 

 the first one. The figure shows the similarity to the vertebrae of Diadectes. 



Genus STEPHANOSPONDYLUS G. and D. 



Phanerosaurus pugnax Geinitz and Deichinuller, Paleontographica, Bd. xxix, 1882, s. 1-46, pis. l-ix. 

 Suphanospondylus pugnax Stappenbeck, Zeitschrift deutsch. geol. Gesell., Bd. 57, 1905, s. 380-437, 



fig- 35. Taf. XIX. 

 Skull rounded, triangular, with rounded snout. Parietal foramen very large. 

 Orbits large and elongate oval in outline. Tabulare little developed. Teeth 



V 



I'iG. 15. — Outline of a dorsal 

 vertebra of Phanerosaurus, 

 After von Meyer. 



Fic. 16. — ^Views of Slephanospondylui. After Stappenbeck. 

 A, top view of tkull; B, lateral view of skull. Lettering as in former figures. 

 C, anterior riew of a dorsal vertebra; D, posterior view of a dorsal vertebra. 



conical, narrowed at base, with labyrinthine arrangement of the enamel. Greatest 

 length of tooth across the axis of the jaw. Acrodont. Incisors simple cones, 

 inclined a little forward. A large canine present. Two rows of cheek teeth in upper 

 jaw. Palate with the curved outer border covered with teeth. Prevomers small, 

 co-ossified. Quadrate plate-like. Vertebrae deeply biconcave, strongly compressed 



