Early snakes had hind legs, according to Yale palaeontologists who have analysed snake genomes and new fossil records.
“We generated the first comprehensive reconstruction of what the ancestral snake was like,” said Allison Hsiang, lead author the study published in the journal BMC Evolutionary Biology.
“We infer that the most recent common ancestor of all snakes was a nocturnal, stealth-hunting predator targeting relatively large prey, and most likely would have lived in forested ecosystems in the Southern Hemisphere,” she said.
The scientists concluded that the most recent common ancestor of all 3,400 species of living snakes would have already lost its forelimbs, but would still have had tiny hind limbs, with complete ankles and toes.
“It would have first evolved on land, instead of in the sea,” said co-author Daniel Field. “Both of those insights resolve longstanding debates on the origin of snakes.”
The ancestral snakes originated about 128.5 million years ago, during the middle Early Cretaceous period, the study suggests. They were non-constricting, wide-ranging foragers that seized their prey with needle-like hooked teeth and swallowed them whole.
“Primate brains, including those of humans, are hard-wired to attend to serpents, and with good reason,” said Jacques Gauthier, senior author of the study.