Fossils That Made Dinosaur History: Coelophysis (1947)

Although Coelophysis was named in 1889 (by the famous paleontologist Edward Drinker Cope), this early theropod didn't make a splash in the popular imagination until 1947, when Edwin H. Colbert found innumerable Coelophysis skeletons tangled together at the Ghost Ranch fossil site in New Mexico. This showed that some genera of small theropods, just like hadrosaurs and ornithopods, traveled in herds--and that large populations of dinosaurs, meat-eaters and plant-eaters alike, were regularly caught unawares by flash floods.