Named By: Lucas - 1904.
Classification: Chordata, Synapsida, Therapsida, Dicynodontia, Kannemeyeriidae.
Species: P. gigas, P. gigus, P. hesternus.
Size: Up to 3.5 meters long.
Known locations: USA, Arizona.
Time period: Carnian to Norian of the Triassic.
Fossil representation: Remains of many individuals.
One of the dicynodonts, Placerias was a low browsing herbivore that had a strong beak and a pair of downwards pointing tusks. With a three and a half meter barrel of a body it was the largest known herbivore of its time. Fossils of forty Placerias discovered in Arizona suggest a herding lifestyle.
- A new batrachian and a new reptile from the Trias of Arizona. Proceedings of the United States National Museum 27:193-195 - F. A. Lucas - 1904.
- Taphonomy and Depositional Setting of the Placerias Quarry (Chinle Formation: Late Triassic, Arizona). - Palaios 15(5):373-386 - Anthony R. Fiorillo, Kevin Padian & Chayanin Musikasinthorn - 2000.
- Skull of the dicynodont Placerias from the Upper Triassic of Arizona - New Mexico Museum of Natural History and Science Bulletin 21, p. 77-85. A. B. Heckert - S. G. Lucas - 2002.
- Limb bone histology and growth in Placerias hesternus (Therapsida: Anomodontia) from the Upper Triassic of North America. - Palaeontology Vol 53, Issue 2, p347–364, March Jeremy L. Green, Mary H. Schweitzer & Ellen-Therese Lamm - 2010.