Temporal range: Late Cretaceous, Maastrichtian
Microhadrosaurus (meaning "small sturdy lizard" in Greek) is a genus of duckbill 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 duckbill, it is based on juvenile remains, and the size of the adult hadrosaur is unknown.
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). Dong later estimated the length of the individual at 2.6 meters (8.5 feet).
Dong regarded this genus as much like Edmontosaurus, albeit in tiny form. 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. The most recent review accepts Brett-Surman's position, and regards Microhadrosaurus as a dubious name.
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. 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. Microhadrosaurus shared its paleoenvironment with the sauropod Gannansaurus, the therizinosauroid Nanshiungosaurus, the tyrannosaurid Qianzhousaurus and the oviraptorids, Banji and Jiangxisaurus.
- Dong Zhiming (1979). "The Cretaceous dinosaur fossils in southern China". In Institute of Vertebrate Paleontology and Paleoanthropology and Nanjing Institute of Paleontology (eds.). 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. The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 438–463. ISBN 0-520-24209-2.
- "Nanxiong Formation". Retrieved 29 September 2013.