Eoraptor

Eoraptor is one of the earliest known dinosaur. This very small theropod dinosaur lived during the late Triassic period in South America. Eoraptor was a small bipedal carnivore that probably reached about 1 meter long. Its size was estimated at 10 kilograms. It had light, hollow bones, a long head with dozens of small, sharp teeth, and five fingers on its grasping hands. 

It was a sprinter that cought a prey and teared it with itsteeth and claws. Eoraptor means "dawn thief." It was first found by Ricardo Martinez in 1991 in Argentina, South America, in the Ischigualasto Basin. This area was a river valley during the late Triassic period but is a dry, eroding desert badlands today. Eoraptor was found in the same rock formation that yielded Herrerasaurus, another very early theropod. Three specimens have been found, all in the Ischigualasto Basin. Eoraptor was named by paleontologists P. Sereno, Forster, Rogers, and Monetta in 1993.