. Carnegie Institution of Washington publication. 3° JERMO-CARBONIFEROUS VERTEBRATES FROM NEW MEXICO. The third vertebra * has lost the neural spine, but judging from the base the spine was broadly diamond-shaped in section with the anterior and posterior edges somewhat extended as in the succeeding vertebras of the presacral series. The neural arch is slightly convex, beginning to assume the form of the neural arch in all the Cotylosauria, but is still much narrower than those of the dorsal series. The anterior zygapophyses are injured, but were evidently of good size. The neural canal is, as
. Carnegie Institution of Washington publication. 3° JERMO-CARBONIFEROUS VERTEBRATES FROM NEW MEXICO. The third vertebra * has lost the neural spine, but judging from the base the spine was broadly diamond-shaped in section with the anterior and posterior edges somewhat extended as in the succeeding vertebras of the presacral series. The neural arch is slightly convex, beginning to assume the form of the neural arch in all the Cotylosauria, but is still much narrower than those of the dorsal series. The anterior zygapophyses are injured, but were evidently of good size. The neural canal is, as the specimen is prepared, of relatively enormous size, having a diameter greater than that of the centrum; this is apparently natural, but if so is a most sur- prising feature. The sides and the bottom of the centrum are concealed by the matrix, but it is apparent that the centrum retains the small size seen in the axis and that there was a large intercentrum. It is a notable fact that throughout the presacral series the accommodation for the intercentrum is largely made by the beveling of the anterior face of each centrum and that there is a much smaller face on the posterior end. The transverse process starts from the side of the anterior zygapophysis near the anterior end and runs downward and forward nearly or quite to the anterior face of the centrum at the lower edge; this is somewhat obscured in the third vertebra, but is very apparent in those immediately following. The upper end of the transverse process stands well out beyond a line connecting the outer edges of the anterior and posterior zygapophyses; in this and the rest of the cervicals the characteristic shortening of the trans- verse process does not appear; it begins at the first of the dorsal vertebrae. The fourth to the seventh vertebrce have lost the neural spines, but the bases show that they were all rather slender, with the diamond-shaped section de- scribed above. The neural arches become gradually wide
Size: 1756px × 1423px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1910, bookyear1913
