New Mexico Geological Society Annual Spring Meeting — Abstracts

One of us (PLS) collected a partial skeleton of a snake from the lower part of the Camp Rice Formation in the southern Palomas basin near Hatch, Dona Ana County, New Mexico. Associated fossil mammals indicate a Blancan (Pliocene) age. The snake fossil consists of an incomplete skull, 9 cervical vertebrae, 44 trunk vertebrae, 27 ribs (3 complete), various fragments and some skin impressions. The trunk vertebrae lack hypapophyses, have long and thin neural spines, vertebrae that are much longer than wide, thin and distinct hemal keels and vaulted neural arches. These features identify the snake as a colubrine, and its strong subcentral ridges and long and thick accessory processes on the vertebrae identify it as Rhinocheilus, a long-nosed snake. Osteologically, it cannot be distinguished from R. lecontei, the extant eastern long-nosed snake, which has a distribution from northern California-Nevada through Arizona-New Mexico-northern Mexico into Texas-Oklahoma. Fossil R. lecontei has also been reported from the Blancan Beck Ranch local fauna of Texas. The R. lecontei from the Camp Rice Formation is thus the first published documentation of a fossil snake from the Santa Fe Group.