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Microhadrosaurus

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Microhadrosaurus
Temporal range: Late Cretaceous, 66.7–66 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Ornithischia
Clade: Neornithischia
Clade: Ornithopoda
Family: Hadrosauridae
Genus: Microhadrosaurus
Species:
M. nanshiungensis
Binomial name
Microhadrosaurus nanshiungensis
Dong, 1979

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

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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

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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

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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

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Fauna and habitat

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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.

See also

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References

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  1. ^ a b 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.
  2. ^ Dong Zhiming (1987). Dinosaurs from China. Beijing: China Ocean Press. pp. 1–114. ISBN 0-565-01073-5.
  3. ^ 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.
  4. ^ a b 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.
  5. ^ "Nanxiong Formation". Archived from the original on 10 August 2014. Retrieved 29 September 2013.