Denson site, locality 41220 (Eocene of the United States)

Where: Colorado (39.5° N, 108.0° W: paleocoordinates 42.2° N, 97.0° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Parachute Creek Member (Green River Formation), Uintan (46.2 - 40.4 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: lacustrine - large; lithified lime mudstone

• Laramide-style block faulting

Size class: macrofossils

Preservation: adpression

Collected by D. Kohls in 1996; reposited in the USNM

Primary reference: G. M. Dlussky and A. P. Rasnitsyn. 2002. Ants (Hymenoptera: Formicidae) of Formation Green River and some other middle Eocene deposits of North America. Russian Entomological Journal 11:411-436 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 138683: authorized by Matthew Clapham, entered by Matthew Clapham on 25.01.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

 Orthoptera - Eumastacidae
Eoerianthus eocaenicus Gorochov 2012 monkey grasshopper
USNM Kohls 50476, 50457, 50484
 Orthoptera - Tetrigidae
Eotetrix unicornis Gorochov 2012 pygmy grasshopper
USNM Kohls 50466
 Orthoptera - Gryllidae
Eozacla arachnomorpha Gorochov 2012 spider cricket
USNM Kohls 50450-AB
Trigonidiinae indet. Saussure 1874 true crickets
USNM Kohls 50454
Gryllinae indet. Laicharting 1781 field cricket
USNM Kohls 50485-AB, 50482-AB
Eogryllus unicolor Gorochov 2012 field cricket
USNM Kohls 50479, 50483
 Orthoptera - Mogoplistidae
Pteromogoplistes ? smithii Scudder 1890 scaly cricket
USNM Kohls 50460
 Hymenoptera - Formicidae
Archimyrmex rostratus Cockerell 1923 bulldog ant
USNM 495989