Eoraptor

The Valley of the Moon in north-western Argentina consists of dusty outcrops of sandstone and mudstone laid down in lushly forested river valleys in late Triassic times. These river banks were prowled by the first dinosaurs, including fox-sized Eoraptor, and various other reptiles that it hunted for food.

Features
Eoraptor is known from a complete skeleton that is lacking only the tail, and in shape and size Eoraptor conforms to every idea of the primitive dinosaur. Its lower jaw lacks the bone joint behind the tooth row that is seen in every other meat-eater, and there is more than one kind of tooth, something unusual in a meat-eating dinosaur. However, all other skeletal features such as the shape of the hips, the upright stance and a reduction of the numbers of fingers on the hand show that this dinosaur was defintely an early theropod.