Othnielia

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iOthnielia
Fossil range: Late Jurassic

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Ornithischia
Suborder:	Ornithopoda
Family:	Hypsilophodontidae
Genus:	Othnielia

Binomial name

Othnielia rex
Galton, 1977

See also Othnielosaurus for more information.

Othnielia is a hypsilophodont dinosaur, named after its describer, Professor Othniel Charles Marsh, an American paleontologist of the 19th century. The taxon, Othnielia rex, was named by Peter Galton in 1977 from a species Marsh (1877) called Nanosaurus rex.

Remains referred to Othnielia have been found in Wyoming, Utah, and Colorado in rocks of the Late Jurassic age (Oxfordian-Tithonian) Morrison Formation, but with Galton's 2006 revision of Morrison ornithischians, the only definite remains are YPM 1875 (the holotype femur of "Nanosaurus" 'rex') and possibly some other associated postcranial bits.

Galton (2006) considered the femur undiagnostic and referred the remaining "Othnielia" material to a new genus, Othnielosaurus. It remains to be seen if this will be widely accepted, but this sort of taxonomic decision has much precedent (for example, Marasuchus versus Lagosuchus).

Without the remains now included in Othnielosaurus, this animal is a nomen dubium, and can only be described in generalities based on similar animals: small (~ 1.5-2 m [4.5-6 ft] long, ~10 kg [22 lb] in mass), agile bipedal herbivore with proportionally small arms and long legs.

[edit] References

Galton, P.M. 1977. The ornithopod dinosaur Dryosaurus and a Laurasia-Gondwanaland connection in the Upper Jurassic. Nature 268: 230-232.
Galton, P.M. 2006. Teeth of ornithischian dinosaurs (mostly Ornithopoda) from the Morrison Formation (Upper Jurassic) of the western United States. in: Carpenter, K. (ed), Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Indiana University Press: Bloomington and Indianapolis, pp. 17-47.
Marsh, O.C. 1877. Notice of new dinosaurian reptiles from the Jurassic formations. American Journal of Sciences (Series 3) 14:514-516.