Ancient snake fossil shows early reptiles inhabited land, sea and underground

An exceptionally intact snake fossil from southeastern Brazil, dated to about 80 million years ago, has been digitally scanned to produce a detailed brain endocast. Lead author Tiago Simões and collaborators determined that the species, named Tametara mirim, possessed cranial features consistent with a fossorial (burrowing) way of life. When contrasted with the Argentine snake Dinilysia patagonica, whose brain morphology indicates a terrestrial habit, the findings highlight divergent ecological strategies among early snakes.

Marine sediment evidence further points to early experiments in aquatic niches. The research, published in Nature, concludes that snake evolution was marked by repeated transitions among underground, surface and marine realms, producing a wide range of sensory adaptations well before the Late Cretaceous. This challenges the long-standing view of a single origin scenario for limbless reptiles.