Dromomeron

Dromomeron (meaning "running femur") is a genus of lagerpetonid dinosauromorph archosaur containing species known from Late Triassic-age rocks of the southwestern United States and northwestern Argentina. It is known from partial remains, largely from the hindlimbs, which indicate an animal with an overall length of less than 1.0 meters (3.3 ft). It is described as most closely related to the earlier Lagerpeton of Argentina, but was found among remains of true dinosaurs like Chindesaurus, indicating that the first dinosaurs did not immediately replace related groups.

Discovery and history

Dromomeron and type species D. romeri is based on GR 218, a complete left thigh bone from the Hayden Quarry at Ghost Ranch, New Mexico. The rocks there are in the lower portion of the Petrified Forest Member of the Chinle Formation, and are Norian in age. Additional hindlimb bones, some probably from the same individual, are also known, and a partial skeleton has been recovered from Hayden Quarry, but has not yet been fully prepared. A few other specimens have been recovered from nearby localities, including the Snyder Quarry. The bones of Dromomeron are most similar to those of the older dinosauromorph Lagerpeton, and the two animals have been classified together in a clade Lagerpetonidae. The species name romeri honors influential 20th century vertebrate paleontologist Alfred Sherwood Romer.