Eunotosaurus (Greek for "original noded lizard"); pronounced YOU-note-oh-SORE-us
Swamps of southern Africa
Late Permian (260-255 million years ago)
Size and Weight:
About one foot long and a few pounds
Small size; wide, shell-like ribs
The ultimate origin of turtles and tortoises is still shrouded in mystery, but many paleontologists believe that these shelled reptiles can trace their ancestry all the way back to the late Permian Eunotosaurus. The striking thing about this small reptile is that it possessed wide, elongated ribs that curved around its back, a kind of "proto-shell" that one can easily imagine evolving (over the course of tens of millions of years) into the giant carapaces of Protostega and Meiolania. As to what kind of reptile Eunotosaurus itself was, that's a matter of debate; some experts think it was a "pareiasaur," a family of ancient reptiles best represented by Scutosaurus.