12 AMERICAN PERMIAN VERTEBRATES 



ASPIDOSAURUS 

 Broili, Paleontographica, LI, 1904. 



Aspidosaurus novomexicanus, n. sp. Plate XXXVIII, Fig. i. Rio 

 Arriba County, New Mexico. Specimen No. 810, Yale 

 Museum. 



The type specimen of this species is inclosed in a hard, rather 

 fine-grained, dark-red, weather-worn sandstone nodule, which is 

 worked with some difficulty. The front extremities, most of the 

 pectoral girdle, save the left scapula and the upper end of the right 

 one, the hind girdles and hind extremities, and the tail had been 

 eroded away before the specimen was discovered by Mr. Baldwin. 

 The specimen was sent in with specimen No. 809 of Limnoscelis 

 paludis Will., and probably had been picked up in the wash among 

 the fragments of that specimen. 



As much as is prudent has been removed of the matrix covering 

 the bones, as shown in the photograph. The skull was attached to 

 the vertebral column at an angle dorsalward of nearly ninety 

 degrees; it has been separated and placed in the plane of the 

 remainder of the specimen; it has lost the nasal portion and much 

 of the mandibles. The upper surface of the skull is markedly 

 concave; its tabular angles are moderately produced into a rounded 

 extremity, but are not turned downward to meet the quadrate, 

 as in Cacops and Dissorophus. The temporal region has a deep 

 emargination not unlike that of Cacops, though not inclosed 

 behind by the tabulare. As this whole region was covered by the 

 sandstone matrix, the absence of the posterior bar cannot be 

 attributed to erosion, nor is there any indication that such a 

 prolongation of the tabularia was present in the living animal and 

 lost in fossilization, especially so as the region is alike on the two 

 sides. Of course, this emargination was for the ear, confirming 

 my views as to the nature of the temporal opening in Trematops, 

 Cacops, and Dissorophus. There are only seven dorsal spinous 

 shields, the first of which, as in Dissorophus, is more than twice 

 the length of the following ones; it is rounded in front. The last 

 shield, also, is much broader antero-posteriorly than from side to 

 side. The shields show little evidence of imbrication. About 



