Earth:Öösh Formation

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Short description: Geological formation in Mongolia
Öösh Formation
Stratigraphic range: Berriasian-Barremian
~141–125 Ma
TypeGeological formation
Sub-unitsCannonball beds
UnderliesBasalt
OverliesBasement
Thickness600 m (2,000 ft)
Lithology
PrimarySandstone, claystone, shale
OtherSiltstone
Location
Coordinates [ ⚑ ] : 44°12′N 102°42′E / 44.2°N 102.7°E / 44.2; 102.7
Paleocoordinates [ ⚑ ] 45°00′N 103°18′E / 45.0°N 103.3°E / 45.0; 103.3
RegionOvorkhangai
Country Mongolia
Öösh Formation is located in Mongolia
Öösh Formation
Öösh Formation (Mongolia)

The Öösh Formation, also known as the Tevsh Formation is a geological formation of Lower Cretaceous strata in Mongolia. Dinosaur remains are among the fossils that have been recovered from the formation.[1] It overlies folded and metamorphosed basement strata of the Gobi region, and is capped by basalt. The succession is around 600 metres thick and consists of red claystones and sandstones, along with black thinly laminated shales. The claystones and sandstones were deposited as part of an alluvial fan system, while the shales were deposited in lakes present in the foot of the fan.[2] Many of the fossils come from the "Cannonball beds", which comprise the lowest 60 metres of the unit and consist of green siltstone.[2]

Vertebrate paleofauna

Dinosaurs

Dinosaurs of the Öösh Formation
Genus Species Location Stratigraphic position Material Notes Images
Asiatosaurus A. mongoliensis Teeth Indeterminate sauropod
Prodeinodon P. mongoliensis Several teeth, fragmentary tibia, fragmentary fibula Indeterminate theropod
Protiguanodon P. mongoliensis Reclassified as a species of Psittacosaurus, Psittacosaurus protiguanodonensis
Psittacosaurus P. mongoliensis
Psittacosaurus fossil from the Hühteeg Svita with gastroliths in its stomach region, American Museum of Natural History
P. protiguanodonensis Junior synonym of P. mongoliensis
Shanag[3] S. ashile[3]

Mammals

Mammals of the Öösh Formation
Genus Species Location Stratigraphic position Material Notes Images
Gobiconodon[4] G. hopsoni[4] Cannonball Member of Öösh Formation, possibly equivalent of Tevsh Formation Two upper and lower jaws (PSS-MAE 140 (Holotype) & PSS-MAE 139)
GobiconodonDB15.jpg

Pterosaurs

Pterosaurs of the Öösh Formation
Genus Species Location Stratigraphic position Material Notes Images
Indeterminate tapejaroid[2][5] "Single cervical vertebra (IGM 100/1321)"[2]

Squamates

Squamates of the Öösh Formation
Genus Species Location Stratigraphic position Material Notes Images
Norellius[6] N. nyctisaurops "Nearly complete skull with mandibles and partial hyoid" Gekkonomorph

See also

  • List of dinosaur-bearing rock formations

References

  1. Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. ISBN:0-520-24209-2.
  2. 2.0 2.1 2.2 2.3 Andres, B. and Norell, M.A. 2005. The first record of a pterosaur from the Early Cretaceous strata of Öösh (Övörkhangai; Mongolia). American Museum Novitates 3472: 1–6. [1]
  3. 3.0 3.1 Turner, A.S.; Hwang, S.H.; Norell, M.A. (2007). "A small derived theropod from Öösh, Early Cretaceous, Baykhangor Mongolia". American Museum Novitates (3557): 1–27. doi:10.1206/0003-0082(2007)3557[1:ASDTFS2.0.CO;2]. http://digitallibrary.amnh.org/dspace/bitstream/2246/5845/1/N3557.pdf. Retrieved 2007-03-29. 
  4. 4.0 4.1 Kielan-Jaworowska, Z., Dashzeveg, D. (1998). "Early Cretaceous amphilestid ("triconodont") mammals from Mongolia". Acta Palaeontologica Polonica 43 (3): 413–438. http://app.pan.pl/archive/published/app43/app43-413.pdf. 
  5. "Tapejaroidea indet.". Fossilworks. http://www.paleofile.com/Pterosaurs/Tapejarincertae.asp. 
  6. Conrad, Jack L.; Daza, Juan D. (2015-08-28). "Naming and rediagnosing the Cretaceous gekkonomorph (Reptilia, Squamata) from Öösh (Övörkhangai, Mongolia)" (in en). Journal of Vertebrate Paleontology 35 (5): e980891. doi:10.1080/02724634.2015.980891. ISSN 0272-4634.