Where: Nei Mongol, China (43.7° N, 112.0° E: paleocoordinates 45.2° N, 105.7° E)

• coordinate based on nearby landmark

When: Arshanto Formation, Arshantan (56.0 - 37.7 Ma)

• "Upper Eocene" from the "Irdin Manha beds" and presumably Irdinmanhan, but Radinsky 1964 shows that correlation to the type section of the Irdin Manha Formation is unfounded

•

•Meng et al. 2007: The upper beds, called ‘‘Houldjin’’ by Granger, are most likely equivalent to bed 12 of Meng et al. (2004), which they considered typical of the Irdin Manha Formation. These strata are now known to form the lower part of the middle beds according to our terminology. The ‘‘Eudinoceras’’ in Granger’s sketch were de- scribed as Gobiatherium mirificum (Osborn and Granger, 1932). This species is the dominant taxon in terms of abundance at this site (appendix 3), and it is regarded as one of the index taxa for the Arshantan (Lucas, 2001). We think that the bed that contains Gobiatherium mirificum (‘‘Eudinoceras’’) in Granger’s section is roughly correlative with the beds that yielded Litolophus, Gobiatherium, and Metacoryphodon within the middle beds of the NHA sequence.

• group of beds-level stratigraphic resolution

Environment/lithology: terrestrial; gray, red claystone

Size class: macrofossils

Collected by Central Asiatic Expedition in 1930; reposited in the AMNH

Primary reference: H. F. Osborn and W. Granger. 1932. Coryphodonts and uintatheres from the Mongolian expedition of 1930. American Museum Novitates 552:1-16 [J. Alroy/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 72184: authorized by John Alroy, entered by John Alroy on 26.05.2007, edited by Philip Mannion

Creative Commons license: CC BY (attribution)