USGS Mesozoic D371, Round Butte (Cretaceous of the United States)

Where: Larimer County, Colorado (40.9° N, 105.1° W: paleocoordinates 47.3° N, 74.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Baculites reesidei ammonoid zone, Larimer Sandstone Member (Pierre Shale Formation), Late/Upper Campanian (83.5 - 70.6 Ma)

• Pierre Shale, from a brown-weathering sandstone concretion in the Larimer Sandstone Member.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified sandstone

Size class: macrofossils

Collected by G.R. Scott in 1955; reposited in the USNM

Primary reference: W. A. Cobban. 1987. The Upper Cretaceous ammonite Rhaeboceras Meek in the western interior of the United States. United States Geological Survey Professional Paper 1477:1-15 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 178348: authorized by Matthew Clapham, entered by Matthew Clapham on 01.05.2016

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Ammonitida - Nostoceratidae
Nostoceras larimerense n. sp. Kennedy et al. 2000 ammonite
Cirroceras conradi Morton 1841 ammonite
Anaklinoceras minutum Kennedy et al. 2000 ammonite
 Ammonitida - Baculitidae
Baculites reesidei Elias 1933 ammonite
 Ammonitida - Diplomoceratidae
Solenoceras texanum Shumard 1861 ammonite
Lewyites oronensis Lewy 1969 ammonite
 Ammonitida - Scaphitidae
Rhaeboceras subglobosum Whiteaves 1885 ammonite