Arctodus pristinus
Arctodus is an extinct genus of short-faced bears that inhabited North America during the Pleistocene. The two recognized species are the lesser short-faced bear and the giant short-faced bear. Of these species, A. simus was larger, is known from more complete remains, and is considered one of the best-known members of North America's extinct Ice Age megafauna. A. pristinus was largely restricted to the Early Pleistocene of the eastern United States, whereas A. simus had a broader range, with most finds being from the Late Pleistocene of the United States, Mexico and Canada. A. simus evolved from A. pristinus, but both species likely overlapped in the Middle Pleistocene. Both species are relatively rare in the fossil record.

Jonathan Chen · CC BY-SA 4.0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.
On record
Recorded, not inferred- Sits inside
- ArctodusPBDB
- Diet
- herbivore, carnivorePBDB, for Ursidae
- Life habit
- ground dwellingPBDB, for Ursidae
- Motility
- actively mobilePBDB, for Osteichthyes
- Environment
- terrestrialPBDB, for Eutheria
Time the record covers
At least 1.6 million years on record.
The record covers at least 1.8 Mya to 129 ka. No occurrence read is dated outside 4.7 Mya to 11.7 ka.
27 occurrences of Arctodus pristinus on record, most of them in the Pleistocene. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.
When
27 occurrences- Pliocene5%
- Pleistocene95%
These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.
Found in
8 formations
- Bermont Formation5
- Wando Formation2
- Tamiami Formation1
- Tacubaya Formation1
- Chapala Formation1
- Ladson Formation1
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The named rock units Arctodus pristinus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 14 occurrences have no formation on record, which is common for older literature.
Arctodus pristinus and its relatives
PleistoceneWhere Arctodus pristinus and its relatives were recorded in the Pleistocene.
Found in the same rock
515 taxa- Equus16 sites
- Odocoileus virginianus13 sites
- Tapirus (Helicotapirus) haysii11 sites
- Dasypus bellus10 sites
- Holmesina floridanus9 sites
- Canis armbrusteri8 sites
- Hemiauchenia macrocephala8 sites
- Paramylodon harlani8 sites
- Pachyarmatherium leiseyi7 sites
- Smilodon gracilis7 sites
- Castoroides dilophidus6 sites
- Cuvieronius tropicus6 sites
- Erethizon dorsatum6 sites
- Lepus6 sites
- Lontra canadensis6 sites
- Panthera onca6 sites
- Blarina carolinensis5 sites
- Eremotherium eomigrans5 sites
- Gopherus polyphemus5 sites
- Homotherium5 sites
- Lynx rufus5 sites
- Mammut americanum5 sites
- Megalonyx wheatleyi5 sites
- Neochoerus aesopi5 sites
The Paleobiology Database records 25 sites for Arctodus pristinus, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.
This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.
Entered from
15 references- Overview of the geology and vertebrate biochronology of the Leisey Shell Pit Local Fauna, Hillsborough County, Florida6
- The fossil record of Arctodus pristinus (Ursidae: Tremarctinae) in Florida4
- Additions to the Pleistocene Mammal Faunas of South Carolina, North Carolina, and Georgia3
- Stratigraphy, paleoecology, and vertebrate fauna of the Leisey Shell Pit Local Fauna, early Pleistocene (Irvingtonian) of southwestern Florida3
- Cenozoic vertebrate biostratigraphy of South Carolina, U.S.A. and additions to the fauna1
- Geology and biostratigraphy of the Potomac River Cliffs at Stratford Hall, Westmoreland County, Virginia1
- Late Pliocene (late Blancan) vertebrates from the St. Petersburg Times site, Pinellas County, Florida, with a brief review of Florida Blancan faunas1
- Historical Biogeography of Florida Pleistocene Mammals1
- Arctodus pristinus Leidy in the Pleistocene of Aguascalientes, Mexico1
- Distribution of Cenozoic vertebrate faunas in Middle America and problems of migration between North and South America1
- Fossil mammals from the Coleman IIA fauna, Sumter County1
- The Pleistocene history of the Appalachian mammal fauna1
Each of the 27 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. 3 further references are not listed. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.
Media and terms
Media content2
Picture of Arctodus pristinus
- Source
- Wikipedia/Commons
- Credit
- Jonathan Chen
- Licence
- CC BY-SA 4.0
- Commercial use
- the licence allows it

Photogrammetry
- Source
- MorphoSource
- Licence
- not stated by the source
- Commercial use
- cannot be read from the licence given — check the record
- Specimen
- Arctodus pristinus · UF:VP:322971
Smithsonian Open Access was not reached for this taxon, so this list is what the others held rather than everything there is.
The description on this site
- Source
- Wikipedia, “Arctodus”
- Licence
- CC BY-SA 4.0
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itArctodus through timeFormations of the PleistoceneThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Leidy 1854