fossil material that included the first evidence of dinosaurs and less-advanced dinosauromorphs from the same time period. The discovery indicates that the two groups lived together during the early Triassic period 235 million years ago. Therrien and Fastovsky (2001) examined the paleoenvironment of Coelophysis and other early theropods from Petrified Forest National Park in Arizona, and determined that this genus lived in an environment that consisted of floodplains marked by distinct dry and wet seasons. There was a great deal of competition during drier times when animals struggled for water in riverbeds that were drying up. In the upper sections of the Chinle Formation where Coelophysis is found, dinosaurs were rare; so far only Chindesaurus and Daemonosaurus are known, the terrestrial fauna being dominated instead by other reptiles like the rhynchocephalian Whitakersaurus; the pseudosuchian Revueltosaurus; the aetosaurs Desmatosuchus, Typothorax and Heliocanthus; the crocodilomorph Hesperosuchus; the "rauisuchians" Shuvosaurus, Effigia and Vivaron; along other rare components like the dinosauriform Eucoelophysis, and the amniote Kraterokheirodon. In the waterways there are the phytosaur Machaeroprosopus; the archosauromorph Vancleavea; the amphibians Apachesaurus and Koskinonodon; and the fishes Reticulodus, Arganodus and Lasalichthyes. Taphonomy The multitude of specimens deposited so closely together at Ghost Ranch was probably the result of a flash flood, which swept away a large number of Coelophysis and buried them quickly and simultaneously. In fact, it seems that such flooding was commonplace during this period of the Earth's history and, indeed, the Petrified Forest of nearby Arizona is the result of a preserved log jam of tree trunks that were caught in one such flood. Whitaker quarry at Ghost Ranch is considered a monotaxic site because it features multiple individuals of a single taxon. The quality of preservation and the ontogenic (age) range of the specimens helped make Coelophysis one of the best known of all genera. In 2009, Rinehart et al. noted that in one case the Coelophysis specimens were "washed into a topographic low containing a small pond, where they probably drowned and were buried by a sheet flood event from a nearby river." The 30 specimens of C. rhodesiensis found together in Zimbabwe was also probably the result of a flash flood, which swept away a large number of Coelophysis and buried them quickly and simultaneously as well. Cultural significance Coelophysis was the second dinosaur in space, following Maiasaura (STS-51-F). A Coelophysis skull from the Carnegie Museum of Natural History was