Microhadrosaurus_nanshiungensis
Microhadrosaurus
Extinct genus of dinosaurs
Microhadrosaurus (meaning "small sturdy lizard" in Greek) is a genus of hadrosaurid dinosaur from the Campanian or Maastrichtian-age Upper Cretaceous Yuanpu Formation (also known as the Nanxiong Formation) of Guangdong, China. Although its name identifies it as a small hadrosaur, it is based on juvenile remains, and the size of the adult hadrosaur is unknown.
| Microhadrosaurus | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Ornithopoda |
| Family: | †Hadrosauridae |
| Genus: | †Microhadrosaurus |
| Species: | †M. nanshiungensis |
| Binomial name | |
| †Microhadrosaurus nanshiungensis Dong, 1979 | |
Dong Zhiming named this genus for IVPP V4732, a partial lower jaw from a juvenile hadrosaur. This partial bone, with 18 columns of stacked teeth in a typical hadrosaur tooth battery, measures 37 centimeters long (15 inches).[1] Dong later estimated the length of the individual at 2.6 meters (8.5 feet).[2]
Dong regarded this genus as much like Edmontosaurus, albeit in tiny form.[1] However, Michael K. Brett-Surman, a hadrosaur specialist, regarded the material as showing no characteristics that would allow it to be differentiated from other duckbills.[3] The most recent review accepts Brett-Surman's position, and regards Microhadrosaurus as a dubious name.[4]
As a hadrosaurid, Microhadrosaurus would have been a bipedal/quadrupedal herbivore, eating plants with a sophisticated skull that permitted a grinding motion analogous to chewing, and was furnished with hundreds of continually-replaced teeth.[4] Because it is only known from a partial jaw from a juvenile, little more than general information can be drawn from it at this point.
Fauna and habitat
The Nanxiong Formation consists of a 2000-meter sequence of red sandstones and clays which has yielded dinosaur fossils, dinosaur footprints and abundant egg shells.[5] Microhadrosaurus shared its paleoenvironment with the sauropod Gannansaurus, the therizinosauroid Nanshiungosaurus, the tyrannosaurid Qianzhousaurus and the oviraptorids Banji, Jiangxisaurus, Corythoraptor, Ganzhousaurus, Huanansaurus, Nankangia and Tongtianlong.
- Dong Zhiming (1979). "The Cretaceous dinosaur fossils in southern China". Mesozoic and Cenozoic Red Beds of South China (in Chinese). Nanxiong, China: Science Press. pp. 342–350.
- Dong Zhiming (1987). Dinosaurs from China. Beijing: China Ocean Press. pp. 1–114. ISBN 0-565-01073-5.
- Brett-Surman, Michael K. (1989). A revision of the Hadrosauridae (Reptilia:Ornithischia) and their evolution during the Campanian and Maastrichtian. Ph.D. dissertation. Washington, D.C.: Graduate School of Arts and Sciences of The George Washington University. pp. 1–272.
- Horner, John R.; Weishampel, David B.; Forster, Catherine A (2004). "Hadrosauridae". In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 438–463. ISBN 0-520-24209-2.
- "Nanxiong Formation". Archived from the original on 10 August 2014. Retrieved 29 September 2013.