Bayan Mandahu Formation

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The Bayan Mandahu Formation (or Wuliangsuhai Formation) is a geological unit of "redbeds" located near the village of Bayan Mandahu in Inner Mongolia, China Asia (Gobi Desert) and dates from the late Cretaceous Period. Laid down in the Campanian, it is dated somewhat uncertainly to between 75-71 mya (million years ago).[1]

Bayan Mandahu Formation
Stratigraphic range: Campanian, 75–71 Ma
TypeGeological formation
Unit ofGobi Desert
Lithology
PrimarySandstone
Location
RegionInner Mongolia
Country China
Type section
Named forBayan Mandahu, Inner Mongolia

DescriptionEdit

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.[2]

FaunaEdit

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.[1]

CrocodylomorphsEdit

Crocodylomorphs of the Bayan Mandahu Formation
Genus Species Location Stratigraphic position Abundance Notes

Shamosuchus[2]

A mesoeucrocodylian.

LizardsEdit

An amphisbaenian species is known from the formation.[2] An iguanian species is known from the formation.[2]

Lizards of the Bayan Mandahu Formation
Genus Species Location Stratigraphic position Abundance Notes

Adamisaurus[2]

A. magnidentatus[2]

An agamid

Bainguis[2]

A diploglossan

Telmasaurus[2]

A monitor lizard

MammalsEdit

A taeniolabidoidea multituberculate is known from the formation.[2]

Mammals of the Bayan Mandahu Formation
Genus Species Location Stratigraphic position Abundance Notes

Kennalestes[2]

K. gobiensis[2]

A placental. Also present in the Djadochta Formation.

Kryptobaatar

K. mandahuensis

The most common mammal in this formation.[1]

A multituberculate.

OrnithischiansEdit

Ornithischian dinosaurs of the Bayan Mandahu Formation
Genus Species Location Abundance Notes Images

Hadrosauridae indet.[3]

Indeterminate[3]

  • Bayan Mandahu[3]

A hadrosaurid.

Magnirostris[1]

M. dodsoni[1]

  • Bayan Mandahu[3]

A ceratopsian

Pinacosaurus[1]

P. mephistocephalus[1]

  • Bayan Mandahu[3]

"Skull, postcranial skeleton, osteoderms."[4]

An ankylosaur

Protoceratops[1]

P. hellenikorhinus[1]

  • Bayan Mandahu[3]

"Complete skull."[5]

A ceratopsian

?Udanoceratops[2]

Indeterminate[2]

  • Bayan Mandahu[3]

A giant ceratopsian

SaurischiansEdit

Saurischian dinosaurs of the Bayan Mandahu Formation
Genus Species Location Abundance Notes Images

cf. Gobipteryx[2]

Indeterminate

Eggs similar to those attributed to Gobipteryx minuta from the Djadochta Formation.

Linheraptor[6]

L. exquisitus[6]

  • Wuliangsuhai[3]

A dromaeosaurid

Linhevenator[7]

L. tani[7]

  • Wuliangsuhai[7]

A troodontid

Linhenykus

L. monodactylus

  • Wuliangsuhai

An alvarezsaurid

Machairasaurus

M. leptonychus

  • Bayan Mandahu[3]

An oviraptorid

Philovenator

P. curriei

  • Wuliangsuhai

A troodontid

Sinornithomimus

S. dongi

  • Wuliangsuhai

An ornithomimid

Velociraptor[2]

V. mongoliensis[2]

Misclassified, only present in the Djadochta Formation.

V. osmolskae

  • Bayan Mandahu[3]

A dromaeosaurid

Wulatelong

W. gobiensis

  • Wuliangsuhai

An oviraptorosaur

Oviraptoridae indet.[3]

Indeterminate[3]

  • Bayan Mandahu[3]

An oviraptorid

Sauropoda indet.[3]

Indeterminate[3]

  • Bayan Mandahu[3]

A sauropod.

Tyrannosauridae indet.[3]

Indeterminate[3]

  • Bayan Mandahu[3]

A tyrannosaurid.

TurtlesEdit

Turtles of the Bayan Mandahu Formation
Genus Species Location Stratigraphic position Abundance Notes

Basilemys[2]

A softshell turtle

See alsoEdit

ReferencesEdit

  1. ^ a b c d e f g h i Godefroit, Pascal; Currie, Philip J.; Li Hong; Shang Chang Yong; Dong Zhi-ming (2008). "A new species of Velociraptor (Dinosauria: Dromaeosauridae) from the Upper Cretaceous of northern China". Journal of Vertebrate Paleontology. 28 (2): 432–438. doi:10.1671/0272-4634(2008)28[432:ANSOVD]2.0.CO;2.
  2. ^ a b c d e f g h i j k l m n o p q Jerzykiewicz, T.; Currie, P.J.; Eberth, D.A.; Johnston, P.A.; Koster, E.H.; Zheng J. (1993). "Djadokhta correlative strata in Chinese Inner Mongolia: An overview of the stratigraphy, sedimentary geology, and paleontology and comparisons with the type locality in the pre-Altai Gobi". Canadian Journal of Earth Sciences. 30: 2180–2195. doi:10.1139/e93-190. [printed early 1994]
  3. ^ a b c d e f g h i j k l m n o p q r s Nicholas R. Longrich; Philip J. Currie; Dong Zhi-Ming (2010). "A new oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of Bayan Mandahu, Inner Mongolia". Palaeontology. 53 (5): 945–960. doi:10.1111/j.1475-4983.2010.00968.x.
  4. ^ "Table 17.1," in Weishampel, et al. (2004). Page 364.
  5. ^ "Table 22.1," in Weishampel, et al. (2004). Page 480.
  6. ^ a b Xu, X., Choinere, J., Pittman, M., Tan, Q., Xiao, D., Li, Z., Tan, L., Clark, J., Norell, M., Hone, D.W.E. and Sullivan, C. (In press). "A new dromaeosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Wuliangsuhai Formation of Inner Mongolia, China." Zootaxa, in press.
  7. ^ a b c Xu X., Tan Q., Sullivan, C., Han F., Xiao D. (2011) A Short-Armed Troodontid Dinosaur from the Upper Cretaceous of Inner Mongolia and Its Implications for Troodontid Evolution. PLoS ONE 6(9): e22916. doi:10.1371/journal.pone.0022916 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0022916