Barun Goyot Formation

Barun Goyot Formation Stratigraphic range: Late Cretaceous approximately 71 million years old.
Type	Geological formation
Thickness	over 100 meters
Location
Region	Asia
Country	Mongolia

The Barun Goyot Formation (West Goyot Formation) is a geological formation dating to the Late Cretaceous Period. It is located within and is widely represented in the Gobi Desert basin, in the Ömnögovi Province of Mongolia.

It was previously known as the "Lower Nemegt Beds" occurring beneath the Nemegt Formation and above the Djadokhta Formation. It has been suggested that the Djadokhta and Barun Goyot formations are lower and upper parts, respectively, of the same lithological unit and the boundary between the two doesn't exist. The stratotype of the Barun Goyot formation is the Khulsan locality, east of Nemegt. At Nemegt, only the uppermost barungoyotian beds are visible. The Red Beds of Khermeen Tsav are also considered part of the Barun Goyot formation. It is approximately 110m in thickness^[1] and was laid down roughly 72-71 million years ago. Given the new date for the start of the Maastrichtian (72.1 MYA) a basal Maastrichtian age seems probable. The Barun Goyot Formation preserves an environment of sand dunes, created from wind-eroded rocks (aeolian dunes).

Vertebrate paleofauna

Saurischians

Genus	Species	Location	Material	Notes	Images
Ajancingenia	A. yanshini	Hermin Tsav[2]		An oviraptorid
Avimimus	Indeterminate	Khulsan[2]		An avimimid similar to Avimimus portentosus from the Nemegt Formation.	Ceratonykus
Ceratonykus	C. oculatus	Hermin Tsav		An alvarezsaurid
Conchoraptor	C. gracilis	Hermin Tsav[2]		An oviraptorid
Gobipteryx	G. minuta		"Embryonic skulls and skeletons."[3]	An enantiornithine
Hollanda	H. luceria			An ornithuromorph
Hulsanpes	H. perlei		"Partial foot."[4]	A maniraptoran of uncertain classification
?Mononykus	Indeterminate	Khulsan[2]		An alvarezsaurid.
Oviraptorinae indet.[2]	Indeterminate	Khulsan[2]		An oviraptorid.
Parvicursor	P. remotus	Khulsan[2]	"Partial postcranial skeleton."[5]	An alvarezsaurid
Sauropoda indet.	Indeterminate	Khulsan[2]
Tarbosaurus?[6]	T. bataar?[6]			A tyrannosaurid, may actually be from the Nemegt Formation.[6]
Velociraptorinae indet.[2]	Indeterminate	Hermin Tsav[2] Khulsan[2]		A dromaeosaurid.

Lizards

Genus	Species	Location	Stratigraphic Position	Abundance	Notes	Images
Estesia	Estesia mongoliensis				An anguimorph.
Ovoo	Ovoo gurvel				A Monitor lizard.
Proplatynotia	Proplatynotia longirostrata
Gobiderma	Gobiderma pulchrum				A Monstersaur.

Mammals

Genus	Species	Location	Stratigraphic Position	Abundance	Notes	Images
Asiatherium	Asiatherium reshetovi				A marsupial.
Asioryctes	Asioryctes nemegetensis				A placental.
Barunlestes	Barunlestes butleri				A placental.
Catopsbaatar	Catopsbaatar catopsaloides				A multituberculate.
Chulsanbaatar	Chulsanbaatar vulgaris				A multituberculate.
Deltatheridium	Deltatheridium pretrituberculare				A marsupial.
Nemegtbaatar	Nemegtbaatar gobiensis				A multituberculate.

Ornithischians

Genus	Species	Location	Material	Notes	Images
Bagaceratops	B. rozhdestvenskyi	Hermin Tsav[2] Khulsan[2]	"[Five] complete skulls, [twenty] fragmentary skulls, postcranial skeletons, juvenile to adult."[7]	A ceratopsian.	Bagaceratops Saichania
Breviceratops	Breviceratops kozlowskii			A ceratopsian.
Lamaceratops	Lamaceratops tereschenkoi			A ceratopsian.
Platyceratops	Platyceratops tatarinovi			A ceratopsian.
Saichania	S. chulsanensis	Hermin Tsav[2] Khulsan[2]	"."[8]	An ankylosaur.
Tarchia	T. kielanae	Khulsan[2]		An ankylosaur.
Tylocephale	T. gilmorei	Khulsan[2]		A pachycephalosaur.
Zaraapelta[9]	Z. nomadis	Hermiin Tsav[9]		An ankylosaur.

Eggs

Oogenus	Oospecies	Location	Material	Notes
Styloolithus[10]	S. sabathi	Khulsan[10]		Probably avian
Faveoloolithus[11]	F. ningxiaensis	Ikh-Shunkht[11]		Possibly sauropod eggs.

See also

• List of fossil sites (with link directory)
• List of dinosaur-bearing rock formations

References

1. Gradzinski, R. Y. S. Z. A. R. D., & Jerzykiewicz, T. O. M. A. S. Z. (1974). Sedimentation of the Barun Goyot formation. Palaeontologica Polonica, 30, 111-146.
2. 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.
3. "Table 11.1," in Weishampel, et al. (2004). Page 213.
4. "Table 10.1," in Weishampel, et al. (2004). Page 199.
5. "Table 11.1," in Weishampel, et al. (2004). Page 211.
6. Mortimer, M (2004). "Tyrannosauroidea". The Theropod Database. Retrieved 2007-08-21.
7. "Table 22.1," in Weishampel, et al. (2004). Page 479.
8. "Table 17.1," in Weishampel, et al. (2004). Page 364.
9. Arbour, V. M., Currie, P. J. and Badamgarav, D. (2014), "The ankylosaurid dinosaurs of the Upper Cretaceous Baruungoyot and Nemegt formations of Mongolia". Zoological Journal of the Linnean Society, 172: 631–652. doi: 10.1111/zoj.12185
10. Varricchio, D.J. and D.E. Barta (2015). "Revisiting Sabath's "Larger Avian Eggs" from the Gobi Cretaceous" Acta Palaeontologica Polonica 60(1):11-25.
11. K. Mikhailov, K. Sabath, and S. Kurzanov. 1994. Eggs and nests from the Cretaceous of Mongolia. In K. Carpenter, K. F. Hirsch, and J. R. Horner (eds.), Dinosaur Eggs and Babies, Cambridge University Press, Cambridge 88-115.