Hell's Half Acre (Lower) (Paleocene of the United States)

Also known as UCM 78009; Kladder M

Where: Mesa County, Colorado (39.3° N, 108.2° W: paleocoordinates 44.6° N, 90.8° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Atwell Gulch Member (DeBeque Formation), Clarkforkian (56.8 - 55.8 Ma)

• "lower part of Atwell Gulch Member"; said to be Clarkforkian

• group of beds-level stratigraphic resolution

Environment/lithology: terrestrial; lithology not reported

Size classes: macrofossils, mesofossils

Primary reference: B. Patterson and R. M. West. 1973. A new late Paleocene phenacodont (Mammalia; condylarthra) from western Colorado. Breviora 403:1-7 [J. Alroy/J. Alroy/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 15252: authorized by John Alroy, entered by John Alroy on 15.05.2002, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Loricata -
Leidyosuchus riggsi n. sp.4 Schmidt 1938 crocodilian
from "Debeque" according to Schmidt, but "Hell's Half Acre" according Bruner 1991
Mammalia
 Cimolesta - Barylambdidae
Barylambda faberi3 Patterson 1933 pantodont
 Cimolesta - Titanoideidae
Titanoides primaevus3 Gidley 1917 pantodont
 Theriamorpha - Stylinodontidae
Ectoganus lobdelli1 Simpson 1929 taeniodont
 Macroscelidea - Apheliscidae
Aletodon cf. gunnelli3 Gingerich 1977 elephant shrew
 Theriamorpha - Viverravidae
Didymictis cf. proteus1 Polly 1997 placental
 Theriamorpha - Phenacodontidae
Phenacodus sp.1 Cope 1873 condylarth
Phenacodus cf. vortmani3 Cope 1880 condylarth
Ectocion osbornianus3 Cope 1882 condylarth
Ectocion parvus3 Granger 1915 condylarth
Ectocion major1 Patterson and West 1973 condylarth
 Procreodi - Arctocyonidae
Thryptacodon cf. australis3 Simpson 1935 condylarth
Lambertocyon ischyrus n. sp.3 Gingerich 1978 condylarth
 Primates - Plesiadapidae
Plesiadapis dubius3 Matthew 1915 primate
Chiromyoides caesor2 Gingerich 1973 primate
 Multituberculata - Ptilodontidae
Ptilodus sp.3 Cope 1881 multituberculate
 Dinocerata - Prodinoceratidae
Probathyopsis harrisorum1 Patterson 1939 uintathere