Fossils of Ghost Ranch

by AMNH on

From the Collections posts

In this episode of Shelf Life, we get a tour of Ghost Ranch, a noted New Mexico fossil bed, which produced specimens like the Coelophysis bauri specimen recreated in the 81st Street subway station. While Coelophysis is among the most notable fossils found at Ghost Ranch, the site is rich with examples of many different species of dinosaurs and crocodilians. Here are some of the other specimens researchers have found during their decades of work at this famed fossil bed.

Effigia okeefeae

Color rendering of an Effigia okeefeae dinosaur, with a beak-like mouth and long neck.
More closely related to crocodiles than dinosaurs, Effigia okeefeae was notable for its beak-like mouth.
Courtesy of N. Tamura

Named for painter Georgia O’Keefe, who spent many years living at Ghost Ranch, this animal was not a dinosaur, but was more closely related to crocodiles. It certainly doesn’t look much like modern crocodilians, though. A bipedal creature with huge eyes, Effigia okeefeae is also notable for its beak-like mouth. 

“It definitely shows a side of early crocodilian relatives that we’ve never really seen before,” says paleontologist Sterling Nesbitt, who discovered and named the species in 2006 while he was a graduate student working with Macaulay Curator of Paleontology Mark Norell.

Tawa hallae

Color rendering of a tawa hallae dinosaur, an early theropod with short claw-like arms and furry skin.
Tawa hallae was an early theropod dinosaur, and thus a distant relative of T. rex.
© J. Gonzalez

This ferocious looking dinosaur, which likely measured about 12 feet from nose to tail in adulthood, dates from the Triassic period, around 215 million years ago. It’s an early example of a theropod dinosaur, the group of dinosaurs that includes Tyrannosaurus rex.

Dromomeron romeri 

A fossil specimen of Dromomeron romeri.
A specimen of Dromomeron romeri from the Ghost Ranch fossil site.
© D. Braginetz

Dromomeron romeri is an example of an archosaur, the group of animals that includes dinosaurs, birds, and crocodiles, among other, less well-known animals. The 2006 discovery of this small archosaur alongside dinosaurs like Coelophysis bauri and Tawa hallae disproved the long held notion that dinosaurs quickly replaced the species that preceded them, with finds from Ghost Ranch suggesting that both dinosaurs and more primitive archosaurs lived alongside one another for tens of millions of years.