The genus Conophis Peters, 1860, contains four species. Three are monotypic and the fourth has three subspecies, making a total of six taxa.
The genus is characterized by maxillary teeth of equal size followed by a diastema and two enlarged grooved fangs. The scales are smooth, in 19 rows at mid-body, and 17 nearer the tail. The anal is divided, apical pits are lacking, the head shields are normal for a colubrid, and the hemipenis is bilobed having many large basal spines.
The six taxa are separated primarily on the basis of color pattern, but characters of scutellation, including numbers of dorsals, ventrals, caudals, and places of reduction of the number of dorsal scale-rows, were analyzed.
Snakes of this genus are distributed throughout semi-arid environments from southern México southward into Costa Rica. They feed upon lizards, primarily of the genus Cnemidophorus; in addition they are known to eat small rodents and other snakes.
Conophis is a member of the subfamily Xenodontinae and, as presently understood, has no known living close relatives. A single specimen of Dryinoides from the Miocene of Montana has been compared with this genus. The genus Conophis is thought to have evolved in Middle America. The present distribution and differentiation probably are primarily the result of climatic fluctuations in Middle America, which produced the areas of subhumid environment where Conophis presently lives.
Auffenberg, W.
1958. A new genus of colubrid snake from the Upper Miocene of North America. Amer. Mus. Novitates, 1874:1-16. February 27.
Cope, E. D.
1861. Contributions to the ophiology of Lower California, México and Central America. Proc. Acad. Nat. Sci. Philadelphia, 13:292-306. December 28.