Mississippi Lime and Material Company Plant No. 2 (Pleistocene of the United States)

Also known as Alton

Where: Illinois (38.9° N, 90.2° W: paleocoordinates 38.9° N, 90.2° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Late/Upper Pleistocene (0.1 - 0.0 Ma)

• age of loess is thought to be either "Sangamon" or (younger and therefore) "Peorian"

• bed-level stratigraphic resolution

Environment/lithology: pond; concretionary conglomerate

• the "loess" is "doubtless aeolian in origin" but the fossils are thought to have been entrapped in "ponds" formed in "a gentle depression at the top of the limestone," which makes sense only if the sequence was glaciation followed by pond formation/fossilization followed by loess deposition
• "In the contact zone between the [glacial, 1-3 feet thick] till and the [reddish] loess" in the local section; the loess has "no notable quantity of sand or suggestion of stratification" while the till is "reddish [and] contains many erratic pebbles of granite, dolerite, greenstone, quartzite, and other Canadian rocks, and also some local rocks"; the glacial till lies immediately over a limestone

Size class: macrofossils

Preservation: concretion

Collected by W. McAdams; reposited in the USNM

• McAdams collection was made "Some time previous to 1883"

Primary reference: M. M. Leighton. 1921. The Pleistocene succession near Alton, Illinois, and the age of the mammalian fossil fauna. Journal of Geology 29(6):505-514 [J. Alroy/J. Alroy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 93486: authorized by John Alroy, entered by John Alroy on 19.01.2010

Creative Commons license: CC BY (attribution)

Taxonomic list

• mammal identifications were made by O. P. Hay (may the buyer beware)

•Polygyra prounda pleistocenica Baker (new ssp.) Polygyra multilineata altonensis Baker (n. ssp.) are both found throughout the lower loess overlying the fossiliferous zone

 Rodentia - Sciuridae
Marmota monax Linnaeus 1758 groundhog
 Rodentia - Geomyidae
Geomys bursarius Shaw 1800 plains pocket gopher
 Rodentia - Castoridae
Castor canadensis Kuhl 1820 American beaver
Castoroides ohioensis Foster 1838 giant beaver
 Perissodactyla - Equidae
Equus sp. Linnaeus 1758 horse
 Carnivora - Ursidae
Ursus americanus Pallas 1780 black bear
 Xenarthra - Megalonychidae
Megalonyx jeffersonii Desmarest 1822 Jefferson's ground sloth
 Proboscidea - Mammutidae
Mammut americanum Kerr 1792 American mastodon
 Ungulata - Tayassuidae
Platygonus ? cumberlandensis Gidley 1920 peccary
 Ungulata - Bovidae
"Symbos promptus" = Bootherium bombifrons, "Taurotragus americanus" = Euceratherium americanum
"Symbos promptus" = Bootherium bombifrons Harlan 1825 antelope
"Taurotragus americanus" = Euceratherium americanum Gidley 1913 shrub-ox
 Ungulata - Cervidae
"Rangifer muscatinensis" = Rangifer tarandus, "Cervalces ? roosevelti" = Cervalces latifrons, Sangamona fugitiva
"Rangifer muscatinensis" = Rangifer tarandus Linnaeus 1758 reindeer
"Cervalces ? roosevelti" = Cervalces latifrons Johnson 1874 stag moose
Sangamona fugitiva Hay 1921 deer