Where: Custer County, South Dakota (43.8° N, 102.8° W: paleocoordinates 45.1° N, 93.9° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Chadron Formation, Chadronian (37.2 - 33.9 Ma)

• ""Lower Oligocene, upper levels of Titanotherium beds"

• group of beds-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; siliciclastic sediments

Size class: macrofossils

Collected by E. S. Riggs in 1898; reposited in the FMNH

Primary reference: B. Patterson. 1931. Occurrence of the alligatoroid genus Allognathosuchus in the Lower Oligocene. Field Museum of Natural History Geological Series 4(6):223-226 [J. Alroy/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 99708: authorized by John Alroy, entered by John Alroy on 19.11.2010

Creative Commons license: CC BY (attribution)