Upper Miocene Snakes (Reptilia, Serpentes) from Southeastern Nebraska

An upper Miocene snake fauna from the Myers Farm Fauna of Webster County, Nebraska, consists of two henophidian and nine caenophidian snakes. It is believed that these snakes lived in a subtropical climate. None of the snakes represent new forms, but some previously described forms are represented by much more complete fossil material. The henophidians are two specialized erycinine boids, previously reported only from the early and middle Miocene. The caenophidians include one heterodontine, three natricine, and three colubrine colubrids; an elapid and a viperid. The dominance of caenophidian over henophidian snakes is a typical situation in North American upper Miocene faunas. Two of the natricines represent the earliest North American Natricinae with well-developed hypapophyses on the trunk vertebrae. The Micrurus is the earliest recorded North American elapid. The presence of modern natricines and elapids in the Myers Farm Fauna and the absence of these forms from the upper Miocene faunas of northcenteral Nebraska may indicate a slightly later age for the Myers Farm fauna.