Coelophysis

Coelophysis bauri is New Mexico's official state fossil, designated in 1981. It was a small, fast-moving predatory dinosaur that lived during the Late Triassic period, making it one of the earliest dinosaurs in the fossil record. New Mexico holds the most important Coelophysis site in the world: a quarry at Ghost Ranch near Abiquiú where hundreds of individuals were found together in a single bone bed.

Coelophysis bauri was a lightly built, bipedal dinosaur up to 9 feet long but weighing only about 40 to 50 pounds. It had a long slender neck, a narrow skull with small serrated teeth, and three-fingered hands tipped with sharp claws. Its bones were hollow — the name Coelophysis means hollow form in Greek — which kept the skeleton light for speed and agility.

Coelophysis was an active predator that chased down small lizards, fish, and insects in the tropical lowlands of Late Triassic New Mexico. It likely lived and moved in groups, based on the evidence of so many individuals preserved together at Ghost Ranch. The species died out about 200 million years ago at the end of the Triassic period.

Coelophysis bauri was first described by Edward Drinker Cope in 1887 from fragmentary bones found in northern New Mexico. The species remained poorly understood until 1947, when paleontologist Edwin Colbert of the American Museum of Natural History uncovered a quarry at Ghost Ranch containing hundreds of articulated Coelophysis skeletons — one of the largest single-species dinosaur bone beds ever found. The Ghost Ranch specimens gave scientists the first complete picture of the animal.

New Mexico designated Coelophysis bauri as its state fossil in 1981, recognizing both the scientific importance of the Ghost Ranch quarry and the state's place as the source of one of the best-documented early dinosaurs. The fossil's prominence grew further in 1998 when a Coelophysis skull was carried to the Mir space station, making it the first dinosaur fossil in space.

The Ghost Ranch quarry near Abiquiú in Rio Arriba County is the type locality and by far the richest Coelophysis site in the world. The Ruth Hall Museum of Paleontology at Ghost Ranch displays specimens recovered from the quarry and tells the story of the 1947 discovery. The site is still active and has yielded material for museums worldwide.

The New Mexico Museum of Natural History and Science in Albuquerque holds additional Coelophysis specimens and provides broader context on the state's Triassic paleoenvironment. Coelophysis fossils have also been found at Chinle Formation outcrops elsewhere in the Colorado Plateau region of New Mexico.