(Named after Othniel Charles Marsh).
Named By: Peter M. galton - 1977.
Synonyms: Nanosaurus rex.
Classification: Chordata, Reptilia, Dinosauria, Ornithischia, Neornithischia.
Species: O. rex.
Size: Uncertain but probably somewhere in the region of 1.5 to 2 meters long.
Known locations: USA.
Time period: Oxfordian/Tithonian of the Jurassic.
Fossil representation: Femur.
Othnielia was originally named as a species of Nanosaurus as N. rex back in 1877 by famed American palaeontologist Othniel Charles Marsh. This was based upon a femur (YPM 1875), but in 1977, a later palaeontologist named Peter Galton renamed the femur as well as some associated skeletal remains as the genus Othnielia, in remembrance to Othniel Charles Marsh, upon the grounds that the original femur could not be assigned to Nanosaurus. However, thirty years later Galton returned to the Othnielia genus and found that the original femur also did not match up to all of the additional fossils remains that had been described as Othnielia. Galton created another new genus for this additional fossil material named Othnielosaurus, leaving the original YPM 1875 femur as the holotype of Othnielia. The femur however is not very distinct, which is also why Othnielia has become regarded as a dubious dinosaur genus, since all of the good fossil material that was once labelled as Othnielia has gone into creating Othnielosaurus.
- Notice of new dinosaurian reptiles from the Jurassic formations. - American Journal of Sciences (Series 3) 14:514-516. - Othniel Charles Marsh - 1877.
- The ornithopod dinosaur Dryosaurus and a Laurasia-Gondwanaland connection in the Upper Jurassic. - Nature 268: 230-232. - Peter M. Galton - 1977.
- A nearly complete dentary of the ornithopod dinosaur Othnielia rex from the Morrison Formation of Wyoming - R. J. Pierce - In, Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin, 36. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 163–164. - J. R. Foster & S. G. Lucas (eds). - 2006.
- Teeth of ornithischian dinosaurs (mostly Ornithopoda) from the Morrison Formation (Upper Jurassic) of the western United States - Peter M. Galton - In, Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Indiana University Press: Bloomington - Kenneth Carpenter (ed) - 2007.
- A photo documentation of bipedal ornithischian dinosaurs from the Upper Jurassic Morrison Formation, USA. - Geology of the Intermountain West. 5: 167–207. - Kenneth Carpenter & Peter M. Galton - 2018.