In 80 million BCE, an ancient reptile left behind a crucial fossil showing how limbs disappeared. 80 million years later, scientists found it suggested early snakes may have evolved across both land and water

An 80-million-year-old fossil discovered in Brazil is offering a new glimpse into how early snakes evolved from lizard-like ancestors. The tiny fossil belongs to a previously unknown species called Tametara mirim . Its unusual brain anatomy suggests that the earliest snakes may have occupied very different environments, rather than following one simple evolutionary path.

The fossil and its significance are detailed in a study published July 22, 2026, in Nature, titled “Exceptional brain and ecological diversity in the earliest snakes.” [Simões, T.R., Sobral, G., Macrì, S. et al.Exceptional brain and ecological diversity in the earliest snakes.Nature(2026)]