Museum explorers uncovered these Coelophysis specimens in a "death assemblage," in which a group of the same animal is found preserved. It is thought that these sites are the results of flooding, when carcasses were washed into a muddy pond and covered with silt.

Coelophysis was an agile, 8- to 10-foot-long dinosaur that weighed about 100 pounds. Its hands and feet were armed with lethal, curved claws to help catch and hold its prey, and the dinosaur's jaws were studded with sharp, serrated teeth to slice through its prey's flesh.