A centuries-old debate on how reptiles keep evolving skin bones is finally settled

Our bones did not begin deep inside the body. They started in the skin, not long after the first complex animals took shape.

Ever since, skin bones have remained a recurring motif in evolution. Yet we still know surprisingly little about them. Why do they keep reappearing in groups as varied as turtles, crocodiles, lizards, snakes and even dinosaurs? And was there a single ancestor with skin bones that gave rise to them all?

In a…

© La Conversation - lundi 12 janvier 2026