Dinosaur ancestor Postosuchus tooth
Very nice Postosuchus tooth fossilized on top of a second tooth of a Postosuchus. Postosuchus was one of the largest carnivorous reptiles during the late Triassic. It was a member of the family of the archosaurs, the ancestors of modern crocodilians as well as the lineage that includes non-avian dinosaurs. Postosuchus lived in what is now North America during the Late Triassic. Where Postosuchus was a closer relative to crocodilians, he had very short forelimbs relative to the hind limbs, which suggest that he may have been committed to bipedal locomotion like later bipedal dinosaurs. Very interesting fossil.
Upper Triassic (227 208 mil y)
Chinle Formation, North Arizona, USA
42 mm - 1.7" (total height)