Discovery Site (Eocene of the United States)

Also known as SC-29

Where: Park County, Wyoming (44.8° N, 109.0° W: paleocoordinates 49.4° N, 92.3° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Willwood Formation, Early/Lower Eocene (55.8 - 48.6 Ma)

• said to be both late Clarkforkian and Eocene

• group of beds-level stratigraphic resolution

Environment/lithology: wet floodplain; lithified, lenticular, brown wackestone

• the "distribution of limestone lenses and the fauna of lens J suggest accumulation in a hollow tree trunk" on a floodplain, not in a lacustrine context, while "the Ectocion limestone [at SC-29] involved slow burial in current winnowed quartz and carbonate sand [in moving water]"
• lens J "is a mottled micritic muddy limestone (wackestone) including gastropod shell fragments, plant debris, and vertebrate bone" that is "brown in unweathered hand specimens"

Size classes: macrofossils, mesofossils

Preservation: replaced with calcite, bone collector

Collected by P. D. Gingerich in 1975; reposited in the UMMP

Collection methods: bulk, quarrying, chemical,

• "The entire lens J fauna [at SC-29] was recovered from a mass of freshwater limestone occupying a volume of approximately 2,000 c3 and weighing an estimated 5 kg" and vertebrates fossil were recovered by "dissolution of the limestone in dilute formic acid (10%)"

Primary reference: P. D. Gingerich. 1987. Early Eocene bats (Mammalia, Chiroptera) and other vertebrates in freshwater limestones of the Willlwood Formation, Clark's Fork Basin, Wyoming. Contributions from the Museum of Paleontology, University of Michigan 27(11):275-320 [J. Alroy/J. Alroy/J. Alroy]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 15081: authorized by John Alroy, entered by John Alroy on 18.02.1993, edited by Will Clyde and Patricia Holroyd

Creative Commons license: CC BY (attribution)

Taxonomic list

• the entire original list applies only to lens J
unclassified
  -
Amphibia
 Caudata - Urodela
Urodela indet. salamander
isolated vertebrae
 Salientia -
Anura indet. frog
distal humerus
Mammalia
 Tribosphenida - Peradectidae
Peradectes protinnominatus4 McKenna 1960 marsupial
 Chiroptera - Icaronycteridae
cf. Icaronycteris sp. Jepsen 1966 bat
a bat
 Soricomorpha - Nyctitheriidae
Limaconyssus habrus n. gen. n. sp. Gingerich 1987 placental
Plagioctenodon thewisseni5 Manz and Bloch 2015 placental
"Leptacodon rosei" = Plagioctenodon rosei Gingerich 1987 placental
Wyonycteris chalix n. gen. n. sp. Gingerich 1987 placental
thought by Gingerich to be a bat, but by Hand et al. 1994 to be a non-chiropteran archontan of unclear affinities
cf. Leptacodon sp. Matthew and Granger 1921 placental
 Ferae - Viverravidae
Viverravus laytoni1 Gingerich and Winkler 1985 placental
Didymictis proteus6 Polly 1997 placental
 Primates - Micromomyidae
Tinimomys graybulliensis Szalay 1974 primate
 Primates - Carpolestidae
Carpolestes simpsoni n. sp.3 Bloch and Gingerich 1998 primate
 Dermoptera -
cf. Worlandia sp. Bown and Rose 1979 colugo
 Multituberculata - Neoplagiaulacidae
Ectypodus powelli Jepsen 1940 multituberculate
Aves
 Telluraves -
Calcardea junnei n. gen. n. sp.
Calcardea junnei n. gen. n. sp. Gingerich 1987 bird
Reptilia
 Squamata -
Varanoidea indet. Gray 1827 squamates
 Testudines - Pantrionychidae
Plastomenus sp.2 Cope 1873 turtle
Gastropoda
 Stylommatophora - Oreohelicidae
Oreohelix megarche Cockerell and Henderson 1912 mountain snail
 Stylommatophora - Pyramidulidae
"Discus ralstonensis" = Pyramidula ralstonensis
"Discus ralstonensis" = Pyramidula ralstonensis Cockerell 1914 slug
 Stylommatophora - Pupillidae
cf. Albertanella minuta Russell 1931 slug
 Stylommatophora - Sagdidae
cf. Microphysula sp. Cockerell 1926 slug
 Stylommatophora - Helicidae
"Hendersonia evanstonensis" = Helix evanstonensis, "Grangerella sinclairi" = Gastrodonta evanstonensis sinclairi
"Hendersonia evanstonensis" = Helix evanstonensis White 1878 slug
"Grangerella sinclairi" = Gastrodonta evanstonensis sinclairi Cockerell 1912 slug
 Heterostropha - Acteonidae
"cf. Pupilla sp." = Pupa (Pupilla)
"cf. Pupilla sp." = Pupa (Pupilla) Leach 1828 snail
Boysia
  -
"cf. Grangerella phenacodorum" = Boysia phenacodorum
"cf. Grangerella phenacodorum" = Boysia phenacodorum Cockerell 1914