Breugnathair elgolensis — a four-legged Jurassic reptile from Scotland described in Nature in 2025 — has emerged as a possible early snake or close snake relative.
Jaw and skull traits give the fossil some distinctly snakelike features, but its overall body still looks lizardlike, leaving researchers split over whether it is a true snake ancestor or a false lead.
That debate matters because the fossil record has not yet pinned down what the first snakes looked like, even though scientists estimate the lineage began about 160 million years ago.
Other evidence suggests snakes later underwent a major evolutionary shift around 125 million years ago, rapidly changing their skulls, diets and spines before diversifying into more than 4,000 living species.
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