Researchers have identified a 3D fragment of fossilized skin that is at least 21 million years than previously described skin fossils. The skin, which belonged to an early species of Paleozoic reptile, has a pebbled surface and most closely resembles crocodile skin. It's the oldest example of preserved epidermis, the outermost layer of skin in terrestrial reptiles, birds, and mammals, which was an important evolutionary adaptation in the transition to life on land. The fossil is described on January 11 in the journal Current Biology along with several other specimens that were collected from the Richards Spur limestone cave system...