260-million-year-old fossil reveals the evolution of turtle shells
Turtle shells are truly remarkable structures. As embryos, turtles’ bones begin to fuse, as ribs, shoulder bones, and vertebrae merge together to form the hard outer shell. That’s an incredible evolutionary adaptation, and the Permian fossil Eunotosaurus helps explain how turtles got their shells. Tyler Lyson, a researcher at Yale University and the Smithsonian, has…
