Named By: Othniel Charles Marsh - 1877.
Classification: Chordata, Reptilia, Dinosauria, Ornithischia, Nanosauridae.
Species: N. agilis (type).
Size: Uncertain due to lack of good fossil remains, but possibly somewhere between 1 and 2 meters long.
Known locations: USA, Colorado - Morrison Formation. Maybe also Wyoming.
Time period: Late Jurassic.
Fossil representation: Based upon partial dentary and fragmentary remains of the skull and post cranial skeleton.
Nanosaurus is an uncertain and some would say dubious genus of ornithopod dinosaur. In the past three species have been named for Nanosaurus, N. agilis, N. rex and N. Victor. The holotype of N. rex was used to create the genus Othnielia in 1977, while N. victor was later realised to be based upon crocodilian remains. This means that the only valid species of Nanosaurus remaining is the type species, N. agilis, but because this is based upon such fragmentary remains, it is very difficult to ascertain genus specific features for this dinosaur.
- Notice of some new vertebrate fossils. - American Journal of Science (Series 3) 14:249-256. - Othniel Charles Marsh - 1877a.
- Notice of new dinosaurian reptiles from the Jurassic formations. - American Journal of Science (Series 3) 14:514-516. - Othniel Charles Marsh - 1877b.
- Principal characters of American Jurassic dinosaurs. Part V. - American Journal of Science 21: 418–423. - Othniel Charles Marsh - 1881.
- The ornithopod dinosaur Dryosaurus and a Laurasia-Gondwanaland connection in the Upper Jurassic. - Nature 268: 230-232. - Peter M. Galton - 1977.
- 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.