harteri) based on a more elongated vertebral shape; longer, lower neural spine; a more depressed neural arch; and in having a shorter, more posteriorly directed hypapophysis
. Moreover, the hypapophysis
is not truncated as in Regina (Holman 1972).
Nonetheless, the hypapophysis of Thamnophis is similar to N.
indet., in that it is rather short and wide, the zygosphene is thick, and the hypapophysis base is thick like a viperid.
1A-B) is placed in the genus Nerodia rather than Thamnophis or Regina based on the short and wide dorsal neural arch region (Brattstrom, 1967), vaulted neural arch, higher neural spine, and the wide, ventrally directed hypapophysis
. The fossil has a higher neural spine than specimens of N.