The Bayan Mandahu Formation (also known as Wulansuhai Formation or Wuliangsuhai Formation) is a geological unit of "redbeds" located near the village of Bayan Mandahu in Inner Mongolia, China, in the Gobi Desert. It dates from the late Cretaceous Period. Laid down in the Campanian, it is dated somewhat uncertainly to between 75 and 71 mya (million years ago).
Description
The paleoenvironment it preserves was semi-arid and characterized by alluvial (stream-deposited) and eolian (wind-deposited) sediments. The formation is known for its vertebrate fossils, most of which are preserved in unstructured sandstone, indicating burial by wind-blown sandstorms.
Paleofauna of the Bayan Mandahu Formation
The fauna of the Bayan Mandahu is very similar in composition to the nearby Djadochta Formation, and the two may have been deposited at roughly the same time. These two formations share many of the same genera, but differ in the makeup of species. For example, the most common mammal in the Djadochta is Kryptobaatar dashzevegi, while in the Bayan Mandahu, it is the closely related Kryptobaatar mandahuensis. Similarly, the dinosaur fauna of the Djadochta includes Protoceratops andrewsi and Velociraptor mongoliensis, while the Bayan Mandahu contains Protoceratops hellenikorhinus and Velociraptor osmolskae.
Crocodylomorphs
Lizards
An amphisbaenian species is known from the formation. An iguanian species is known from the formation.
Turtles
Mammals
A taeniolabidoidea multituberculate is known from the formation.
Dinosaurs
Alvarezsaurs
Ankylosaurs
Birds
Ceratopsians
Dromaeosaurs
Hadrosaurs
Oviraptorosaurs
Sauropods
Troodontids
Tyrannosaurs
See also
- Barun Goyot Formation
- List of fossil sites (with link directory)
- Nemegt Formation
- List of dinosaur-bearing rock formations
References
Bibliography
- Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2, retrieved 2019-02-21
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