Tetrapodophis

Tetrapodophis (Greek meaning "four-footed snake") is an extinct genus of lizard from the Early Cretaceous (Aptian) aged Crato Formation of Brazil. It has an elongated snake-like body, with four disproportionately short limbs. The species is known from one fossil specimen.

Tetrapodophis has been considered by some researchers to be one of the oldest members of Ophidia, which is the taxonomic group which includes snakes and some of their closest extinct relatives. However, this classification has been disputed by some other authors, who recovered Tetrapodophis as a dolichosaurid, though the exact phylogenetic placement of Dolichosauridae is also disputed; Dolichosaurids may be related to Ophidia, which would mean that Tetrapodophis is indeed related to snakes, albeit more distantly than previously thought. Alternatively, dolichosaurids could be more closely related to mosasaurs, which may also be the closest relative of snakes.