PBDB Collection

Amtgai [HMNS-GIN] (Cretaceous to of Mongolia)

Also known as Amtgai Khuduk, Amtgay

Where: Omnogov, Mongolia (43.6° N, 107.9° E: paleocoordinates 45.5° N, 98.3° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Baynshire Formation, Cenomanian to Cenomanian (100.5 - 83.6 Ma)

• Bayn Shire

•

•Kurumada et al. 2020: Two meaningful calcite U–Pb ages were obtained; 95.9 ± 6.0 and 89.6 ± 4.0 Ma, which are consistent with published ages from the Bayn Shire Formation.

• bed-level stratigraphic resolution

Environment/lithology: fluvial; lithified, fine-grained, white, blue sandstone and gray mudstone

• "...alternation of sandstone and mudstone layers with gray to bluish white color...Paleocurrent direction on trough cross-stratification on hard fine-grained sandstone layer is 239 degree."

Size class: macrofossils

Collected by HMNS-GIN in 1993-1994, 2001

Collection methods: surface (in situ),

• HMNS-Hayashibara Museum of Natural Sciences

Primary reference: M. Watabe and S. Suzuki. 2000. Report on the Japan–Mongolia Joint Paleontological Expedition to the Gobi desert, 1993. Hayashibara Museum of Natural Sciences Research Bulletin 1:17-29 [R. Benson/R. Benson/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 127666: authorized by Roger Benson, entered by Roger Benson on 21.05.2012, edited by Matthew Carrano

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names

Osteichthyes
Osteichthyes -	Osteichthyes indet.⁶ Osteichthyes indet.⁶ Huxley 1880 bony fish
Reptilia
Testudinata -	Testudinata indet.⁵ Testudinata indet.⁵ Oppel 1811 turtle
Testudines - Trionychidae	Trionychidae indet.³ Trionychidae indet.³ Gray 1825 softshell turtle shell fragments
Testudines - Adocidae	Adocidae indet.³ Adocidae indet.³ Cope 1869 turtle shell fragments
Testudines - Nanhsiungchelyidae	Nanhsiungchelyidae indet.³ Nanhsiungchelyidae indet.³ Yeh 1966 turtle shell fragments
Testudines - Lindholmemydidae	Lindholmemydidae indet.³ Lindholmemydidae indet.³ Chkhikvadze 1970 turtle shell fragments
Dinosauria -	Dinosauria indet. Dinosauria indet. Owen 1842 dinosaur 930821 AMG, skull
Theropoda -	Theropoda indet. Theropoda indet. Marsh 1881 theropod claw, caudal; postcranium, 040802 AMT-N Tsui
Ornithischia - Ankylosauridae	Ankylosauridae indet.² Ankylosauridae indet.² Brown 1908 ankylosaurid many fragmentary hadrosaur and ankylosaur bones. [Then later, in 2001]: ankylosaur skull and scute fragments
Ornithischia -	Hadrosauroidea indet.⁴ Hadrosauroidea indet.⁴ Huene 1954 ornithopod many fragmentary hadrosaur and ankylosaur bones. [Then later, in 2001]: hadrosaur bone elements (skull and postcranials)
Ornithischia - Pachycephalosauridae	Amtocephale gobiensis⁷ Amtocephale gobiensis⁷ Watabe et al. 2011 ornithischian pachycephalosaurian cranial case
Saurischia -	Sauropoda indet., ? Sauropoda indet.¹ Sauropoda indet. Marsh 1878 sauropod sauropod vertebrae, ribs, teeth, femur ? Sauropoda indet.¹ Marsh 1878 sauropod partial tibia?; 930821 AMG
Crocodylia -	Crocodylia indet.⁶ Crocodylia indet.⁶ Owen 1842 crocodilian

Mollusca -	Mollusca indet.⁵ Mollusca indet.⁵ mollusk molluscan shells

¹Matsumoto et al. 2000; ²Matsumoto et al. 2010; ³Suzuki and Narmandakh 2004; ⁴Tsogtbaatar and Chinzorig 2007; ⁵Watabe and Suzuki 2000; ⁶Watabe et al. 2004; ⁷Watabe et al. 2011