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

• 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

 Mollusca -
Mollusca indet.2 mollusk
molluscan shells
Osteichthyes
 Osteichthyes -
Osteichthyes indet.3 Huxley 1880 bony fish
Reptilia
 Testudinata -
Testudinata indet.2 Oppel 1811 turtle
 Testudines - Trionychidae
Trionychidae indet.1 Gray 1825 softshell turtle
shell fragments
 Testudines - Nanhsiungchelyidae
Nanhsiungchelyidae indet.1 Yeh 1966 turtle
shell fragments
 Testudines - Adocidae
Adocidae indet.1 Cope 1869 turtle
shell fragments
 Testudines - Lindholmemydidae
Lindholmemydidae indet.1 Chkhikvadze 1970 turtle
shell fragments
 Dinosauria -
Dinosauria indet. Owen 1842 dinosaur
930821 AMG, skull
 Saurischia -
Sauropoda indet. Marsh 1878 sauropod
sauropod vertebrae, ribs, teeth, femur
Theropoda indet. Marsh 1881 theropod
claw, caudal
 Ornithischia -
Ankylosauria indet. Osborn 1923 ornithischian
many fragmentary hadrosaur and ankylosaur bones. [Then later, in 2001]: ankylosaur skull and scute fragments
 Neornithischia - Pachycephalosauridae
Amtocephale gobiensis4 Watabe et al. 2011 ornithischian
pachycephalosaurian cranial case
 Neornithischia - Hadrosauridae
Hadrosauridae indet. Cope 1869 hadrosaurid
many fragmentary hadrosaur and ankylosaur bones. [Then later, in 2001]: hadrosaur bone elements (skull and postcranials)
 Crocodylia -
Crocodylia indet.3 Owen 1842 crocodilian