An enigmatic aquatic snake from the Cenomanian of Northern South America.

Adriana Albino,Jorge D Carrillo-Briceño,James M Neenan

doi:10.7717/peerj.2027

Abstract

We report the first record of a snake from the Cretaceous of northern South America. The remains come from the La Luna Formation (La Aguada Member, Cenomanian of Venezuela) and consist of several vertebrae, which belong to the precloacal region of the vertebral column. Comparisons to extant and extinct snakes show that the remains represent a new taxon, Lunaophis aquaticus gen. et sp nov. An aquatic mode of life is supported by the ventral position of the ribs, indicating a laterally compressed body. The systematic relationships of this new taxon are difficult to determine due to the scarcity of fossil material; it is, however, a representative of an early lineage of snakes that exploited tropical marine pelagic environments, as reflected by the depositional conditions of the La Aguada Member. Lunaophis is also the first aquatic snake from the Cenomanian found outside of the African and European Tethyan and Boreal Zones.

Highlights

Until recently, the oldest record of snakes has been from the Albian of Algeria (Cuny et al, 1990) and the Albian–Cenomanian of North America (Gardner & Cifelli, 1999), whereas a supposed snake from the Barremian of Spain (Rage & Richter, 1994) was recently excluded from the group (Rage & Escuillié, 2003)
We report the first record of a snake from the Cretaceous of northern South America
The remains come from the La Luna Formation (La Aguada Member, Cenomanian of Venezuela) and consist of several vertebrae, which belong to the precloacal region of the vertebral column

Summary

Introduction

The oldest record of snakes has been from the Albian of Algeria (Cuny et al, 1990) and the Albian–Cenomanian of North America (Gardner & Cifelli, 1999), whereas a supposed snake from the Barremian of Spain (Rage & Richter, 1994) was recently excluded from the group (Rage & Escuillié, 2003). These records have few phylogenetically informative characters and add little to the knowledge of the origin and early evolution of snakes.

Methods

Results

Discussion

Conclusion