Everyone thought the first real turtles came around in the late Cretaceous period. But they were wrong. In 2008 two major discoveries were found. The first was western European Eileanchelys, touted by researchers as the
earliest marine turtle yet identified. Unfortunately, only a few weeks later,
Chinese paleontologists announced the discovery of Odontochelys, which lived a whopping 50 million years earlier. Crucially, this soft-shelled marine turtle possessed a full set of teeth, which subsequent turtles gradually shed over tens of millions of years of evolution. ; another important prehistoric turtle, Proganochelys, pops up in the western European fossil record about 10 million years later. This much bigger turtle had fewer teeth than Odontochelys, and the prominent spikes on its neck meant that it couldn't fully retract its head under its shell (it also had an ankylosaur-like clubbed tail). Most important, the carapace of Proganochelys was "fully baked": hard, snug and pretty much impervious to hungry predators.
earliest marine turtle yet identified. Unfortunately, only a few weeks later,
Chinese paleontologists announced the discovery of Odontochelys, which lived a whopping 50 million years earlier. Crucially, this soft-shelled marine turtle possessed a full set of teeth, which subsequent turtles gradually shed over tens of millions of years of evolution. ; another important prehistoric turtle, Proganochelys, pops up in the western European fossil record about 10 million years later. This much bigger turtle had fewer teeth than Odontochelys, and the prominent spikes on its neck meant that it couldn't fully retract its head under its shell (it also had an ankylosaur-like clubbed tail). Most important, the carapace of Proganochelys was "fully baked": hard, snug and pretty much impervious to hungry predators.