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.
Description
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]
History
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]
Paleobiology
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.
Paleoecology
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.
