Eunotosaurus

Eunotosaurus is a genus of reptile, possibly a close relative of turtles, from the late Middle Permian (Capitanian stage) Karoo Supergroup of South Africa. It is often considered as a possible "missing link" between turtles and their prehistoric ancestors. Its ribs were wide and flat, forming broad plates similar to a primitive turtle shell, and the vertebrae were nearly identical to those of some turtles. It is possible that these turtle-like features evolved independently of the same features in turtles, though some studies suggest Eunotosaurus is a genuine, primitive turtle relative. Other anatomical studies and phylogenetic analysis suggest that Eunotosaurus is a parareptile and not a basal turtle.[1][2]