Bayan Shireh Formation
| Bayan Shireh Formation Stratigraphic range: Late Cretaceous (Cenomanian-Santonian?) |
|
|---|---|
| Type | Geological formation |
| Sub-units | "Sheeregeen Gashoon" beds (upper Bayan Shireh) |
| Location | |
| Region | Asia |
| Country | Mongolia |
The Bayan Shireh Formation (also known as Bayanshiree Svita or the Baynshirenskaya Formation) is a geological formation in Burkhant, Mongolia, that dates to the late Cretaceous period. The exact age is uncertain, with two competing hypotheses; based on comparisons with other formations, the Bayan Shireh fauna seems to correspond best with the Turonian through early Campanian stages of the Late Cretaceous, about 93 to 80 million years ago.[1] However, examination of the magnetostratigraphy of the formation seems to confirm that the entire Bayan Shireh lies within the Cretaceous Long Normal, which lasted only until the end of the Santonian stage, giving a possible Cenomanian through Santonian age, or between 98 and 83 million years ago.[2] The fauna of this formation is similar to the nearby Iren Dabasu Formation.
Fauna
Theropod dinosaurs
| Theropods reported from the Bayan Shireh Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic Position | Material | Notes | Images |
|
"Partial skull and fragmentary postcrania."[3] |
a giant dromaeosaur |
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|
a tyrannosaur. Also present in the Iren Dabasu Formation |
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|
"Incompletely preserved pelvis."[4] |
a therizinosaur |
|||||
|
"Skull, pes, [and a] fragmentary postcranium."[4] |
a therizinosaur |
|||||
|
"Skull with associated incomplete postcranium."[5] |
an ornithomimosaur |
|||||
|
"[Three] specimens, including mandible pelvis, hindlimb, scapulocoracoid, incomplete forelimb, [and] fragmentary vertebrae."[4] |
a therizinosaur |
|||||
Ornithischian dinosaurs
| Ornithischians reported from the Bayan Shireh Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic Position | Material | Notes | Images |
|
A. magnus |
"Fragmentary skull."[6] |
|||||
|
Sheeregeen Gashoon beds |
"Partial skull, skeleton."[7] |
A primitive ceratopsian, also present in the Minhe Formation |
||||
|
Sheeregeen Gashoon beds |
an ankylosaur |
|||||
|
Sheeregeen Gashoon beds |
A primitive ceratopsian, also present in the Minhe Formation |
|||||
|
"More than [five] specimens, including [two] partial skulls, nearly complete skeleton, osteoderms."[8] |
an ankylosaur |
|||||
|
"Skull."[8] |
an ankylosaur |
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See also
References
- ↑ Jerzykiewicz, T. and Russell, D.A. (1991). "Late Mesozoic stratigraphy and vertebrates of the Gobi Basin." Cretaceous Research, 12(4): 345-377.
- ↑ Hicks, J.F., Brinkman, D.L., Nichols, D.J., and Watabe, M. (1999). "Paleomagnetic and palynological analyses of Albian to Santonian strata at Bayn Shireh, Burkhant, and Khuren Dukh, eastern Gobi Desert, Mongolia." Cretaceous Research, 20(6): 829-850.
- ↑ "Table 10.1," in Weishampel, et al. (2004). Page 198.
- ↑ 4.0 4.1 4.2 "Table 7.1," in Weishampel, et al. (2004). Page 152.
- ↑ "Table 6.1," in Weishampel, et al. (2004). Page 138.
- ↑ "Table 17.1," in Weishampel, et al. (2004). Page 367.
- ↑ "Table 22.1," in Weishampel, et al. (2004). Page 480.
- ↑ 8.0 8.1 "Table 17.1," in Weishampel, et al. (2004). Page 364.
