Dromomeron Temporal range: Late Triassic, 220–211.9 Ma |
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Hypothetical reconstruction of Dromomeron romeri | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Ornithodira |
Clade: | Dinosauromorpha |
Family: | †Lagerpetidae |
Genus: |
†Dromomeron Irmis et al., 2007 |
Species | |
Dromomeron (meaning "running femur") is a genus of lagerpetonid dinosauromorph archosaur that lived around 220 to 211.9 ± 0.7 million years ago. The genus containing species known from Late Triassic-age rocks of the southwestern United States and northwestern Argentina. 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.
Based on the study of the overlapping material of Dromomeron and Tawa hallae, Christopher Bennett proposed that the two taxa were conspecific, forming a single growth series of Dromomeron.
It is known from partial remains, largely from the hindlimbs, which indicate an animal with an overall length of 1 meters (3.3 ft).
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.
Cladogram simplified after Kammerer, Nesbitt & Shubin (2012):
Dromomeron gregorii
Dromomeron romeri
The species name romeri honors influential 20th-century vertebrate paleontologist Alfred Sherwood Romer.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. Other specimens from the Chinle Formation of Arizona and a roughly contemporaneous part of the Dockum Group of Texas also have been assigned to this genus. These have been assigned to second species D. gregorii, named in 2009.