Thrinaxodon, cynodont (therapsid) Pteranodon about the time that dinosaurs

about the time that dinosaurs began to appear

Their tails were relatively stiff and probably used for balance

This 2 plus inch long fossil shark tooth comes from the extinct fossil shark Otodus obliquus

5 million years ago: Homo habilis

Thrinaxodon, cynodont (therapsid) Pteranodon about the time that dinosaursThrinaxodon (pronounced thrin AX ah DON) was a cat sized cynodont, an ancestor of the mammals, but not a mammal itself. Thrinaxodon was not a dinosaur. This therapsid lived during the late Triassic period, roughly 240 million years ago. Small holes in the snout bones suggest that it may have had whiskers, a mammalian characteristic. Its teeth were also similar to those of mammals. The skull was about 1. 5 inches long. Fossils have been found in South