Eighty million years ago, in what is now Brazil, a small snake lived and died in darkness beneath the soil — and in 2020, its intact skull emerged from a quarry to settle one of paleontology's most enduring arguments. The fossil, named Tametara mirim, carries within its stone-preserved braincase the evidence that snakes did not arise from a single ancestral way of life, but from many simultaneous experiments in living. Compared against the Argentine Cretaceous snake Dinilysia patagonica — a surface dweller with an entirely different sensory world — Tametara mirim reveals that diversity, far fr