A primitive snake from the Cretaceous of Utah

Recently discovered vertebrae of the anilioid-grade snake Coniophis from the Cretaceous (uppermost Albian/lowermost Cenomanian) upper Cedar Mountain Formation of Utah, USA, are among the oldest known snake fossils and extend the record of snakes in the New World back by at least 10 My. The vertebrae from Utah and other occurrences of Albian to Cenomanian snake fossils support suggestions that Alethinophidia and its inferred sister-taxon, Scolecophidia, originated before the Late Cretaceous, and indicate that 'anilioids' were widely distributed (Laurasia, Gondwana) by the early Late Cretaceous. If 'anilioids' emigrated from South to North America, as is widely believed, the fossils from Utah demonstrate that this must have occurred before the latest Cretaceous emigration event previously hypothesized. The broad distribution of 'anilioids' in the Late Cretaceous, coupled with the possibility that snakes may have first appeared in the Jurassic, suggests that snakes may have been present in North America prior to its separation from Gondwana.