Wikipedia

Arctodus

genus of mammals

Arctodus is an extinct genus of short-faced bear endemic to North America during the Pleistocene era about 2.5 million years ago to 12,800 years ago. There were two species, Arctodus pristinus and Arctodus simus.

Arctodus
Temporal range: Pleistocene 2.5–0.0128 Ma
↓
A. simus from the La Brea tar pits
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Ursidae
Subfamily: Tremarctinae
Genus: †Arctodus
Leidy, 1854
Type species
†Arctodus pristinus
Leidy, 1854
Species
  • †A. pristinus (Leidy, 1854)
  • †A. simus (Cope, 1879)
Maximum range of Arctodus simus.

The giant short-faced bear, Arctodus simus, evolved from Arctodus pristinus during the middle Pleistocene of North America, around 1.3 million years ago. Both species were omnivorous, feeding on tall vegetation and large mammals. Arctodus simus might have been the largest predatory land mammal that ever lived in North America.

Habitat change

Both species of Arctodus lived in different habitats, with Arctodus pristinus preferred dense forests in eastern North America,[1] and Arctodus simus inhabiting open forests in western North America. However, after the extinction of Arctodus pristinus, the giant short-faced bear spread east in small numbers.[2]

Arctodus pristinus was particularly common on the east coast, with the largest concentrations being in Florida.[3] Additional finds are from Pennsylvania, West Virginia, Kansas and Aguascalientes (Mexico).[4][5]

Arctodus simus lived in much of North America, ranging from Alaska to Puebla in the west,[6] to Virginia and Florida in the east.[2][5] This species is first found in California,[5][7] and was most common in the savannas and pinon-juniper woodlands of the western United States and Mexico, where many other megafauna lived.[8][9]

Fossils change

The oldest Arctodus fossils are from the Kissimmee River & Santa Fe River paleontological sites in Florida, belonging to Arctodus pristinus.[3] The first fossils of the Arctodus simus were found the Potter Creek Cave in Shasta County, California, by Edward Drinker Cope,[10] with the oldest being from Irvington, California.[5]

Paleontologists have found only one Arctodus simus skeleton in Indiana.[11] It is famous because it was the biggest most-nearly complete skeleton of a giant short-faced bear ever found in America. The original bones are in Chicago's Field Museum of Natural History.[12]

Males were much larger than females.[13] When it was standing on its back legs, Arctodus simus was 8–11 feet (2.4–3.4 m) tall.[14] A 2010 study estimated the weight of six Arctodus simus individuals, with a weight range between 317 kg (699 lb) and 957 kg (2,110 lb). In comparison, Arctodus pristinus specimens have been calculated to an average of ~133 kg (293 lb),[15] although some northern and western Arctodus pristinus were the same size as small Arctodus simus.[5]

Behavior change

Both species were omnivores, browsing on shrubs and trees, and eating browsers like deer, camels, llamas, tapirs, ground sloths, and wood bison,[16][17] Dental damage from eating carbohydrates,[18][19][20] and seeds in Arctodus simus' poop proves plants were consumed,[21][22] while bone damage on prey matches both Arctodus species' teeth.[13][23][24][25] Analyses of Arctodus simus' bone chemicals confirm that the giant short-faced bear lived in open forests and other vegetated areas, and sometimes ate other open forest inhabitants.[17][26][27][28][29][30]

 
The skeleton of Arctodus pristinus, from The Bishop Museum of Science and Nature, Florida.

Past research change

One theory was that the giant short-faced bear was an active predator, attacking herbivores directly.[31] Another theory was that it let faster predators make the kill, then bullied them off the carcass, being a scavenger.[32] Finally, anatomy led some to believe it was a herbivore.[33] Modern research establishes all three behaviors were present in Arctodus simus.[16]

Previous theories also suggested that brown bears caused the extinction of Arctodus simus, and that the giant short-faced bear prevented people from migrating into North America.[34] However, these ideas have been rejected,[35] with new dates confirming both co-existed with Arctodus simus.[36][37]

Extinction change

The replacement of hot & humid forests with open habitats, along with competition with black bears and Tremarctos floridanus, led to the extinction of Arctodus pristinus 300,000 years ago.[3] Arctodus simus went extinct around 12,800 years ago,[38][39] which was likely due to ecological collapse leading to fewer prey and quality vegetation.[34]

References change

  1. ↑ Russell, Dale A.; Rich, Fredrick J.; Schneider, Vincent; Lynch‐Stieglitz, Jean (May 2009). "A warm thermal enclave in the Late Pleistocene of the South‐eastern United States". Biological Reviews. 84 (2): 173–202. doi:10.1111/j.1469-185X.2008.00069.x. ISSN 1464-7931.
  2. ↑ 2.0 2.1 Schubert, Blaine W.; Hulbert, Richard C.; Macfadden, Bruce J.; Searle, Michael; Searle, Seina (January 2010). "Giant short-faced bears ( Arctodus simus ) in Pleistocene Florida USA, a substantial range extension". Journal of Paleontology. 84 (1): 79–87. doi:10.1666/09-113.1. ISSN 0022-3360.
  3. ↑ 3.0 3.1 3.2 Emslie, Steven D. (1995). "The fossil record of Arctodus pristinus (Ursidae: Tremarctinae) in Florida" (PDF). Bulletin of the Florida Museum of Natural History. 37: 501–514 – via Florida Museum.
  4. ↑ I. Ferrusquia-Villafranca. 1978. Bol Univ Nac Aut Mex Inst Geol 101:193-321
  5. ↑ 5.0 5.1 5.2 5.3 5.4 Richards, Ronald L.; Churcher, C.S.; Turnbull, William D. (1996-12-31), "Distribution and size variation in North American Short-faced bears, Arctodus simus", Palaeoecology and Palaeoenvironments of Late Cenozoic Mammals, University of Toronto Press, pp. 191–246, doi:10.3138/9781487574154-012, ISBN 978-1-4875-7415-4, retrieved 2023-11-30
  6. ↑ C.S. Churcher, A.V. Morgan, and L.D. Carter. 1993. Arctodus simus from the Alaskan Arctic Slope. Canadian Journal of Earth Sciences 30(5):1007-1013, collected by A.V. Morgan
  7. ↑ M.L. Cassiliano. 1999. Biostratigraphy of Blancan and Irvingtonian mammals in the Fish Creek-Vallecito Creek section, southern California, and a review of the Blancan-Irvingtonian boundary. Journal of Vertebrate Paleontology 19(1):169-186
  8. ↑ Pichardo, Mario (2003-06-13). "Overview of Central Mexican Prehistory: Morphostratigraphy, Chronostratigraphy, Biostratigraphy". Anthropologischer Anzeiger. 61 (2): 141–174. doi:10.1127/anthranz/61/2003/141. ISSN 0003-5548.
  9. ↑ Martin, Larry; Neuner, A. (1978-01-01). "The End of the Pleistocene in North America". Transactions of the Nebraska Academy of Sciences and Affiliated Societies.
  10. ↑ Cope E.D. 1879. The cave bear of California. American Naturalist, 13:791.
  11. ↑ Richards, Ronald L.; Richards, Ronald L.; Neiburger, Ellis J.; Turnbull, William D. (1995). Giant short-faced bear (Arctodus simus yukonensis) remains from Fulton County, northern Indiana. Chicago, Ill: Field Museum of Natural History.
  12. ↑ Stark, Mike (April 2022). Chasing the Ghost Bear: On the Trail of America's Lost Super Beast. U of Nebraska Press. ISBN 978-1-4962-2902-1.
  13. ↑ 13.0 13.1 "Arctodus pristinus". Florida Vertebrate Fossils. Retrieved 2023-11-30.
  14. ↑ Fisher, W. A. (2018-02-05). "How Big Was This Short-Faced Bear?". North American Bear Center. Retrieved 2023-11-30.
  15. ↑ Van Valkenburgh, Blaire; Hayward, Matthew W.; Ripple, William J.; Meloro, Carlo; Roth, V. Louise (2016-01-26). "The impact of large terrestrial carnivores on Pleistocene ecosystems". Proceedings of the National Academy of Sciences. 113 (4): 862–867. doi:10.1073/pnas.1502554112. ISSN 0027-8424. PMC 4743832. PMID 26504224.
  16. ↑ 16.0 16.1 Figueirido, Borja; Pérez-Claros, Juan A.; Torregrosa, Vanessa; Martín-Serra, Alberto; Palmqvist, Paul (2010-01-29). "Demythologizing Arctodus simus , the 'short-faced' long-legged and predaceous bear that never was". Journal of Vertebrate Paleontology. 30 (1): 262–275. doi:10.1080/02724630903416027. ISSN 0272-4634.
  17. ↑ 17.0 17.1 PéRez-Crespo, VíCtor AdriáN; Arroyo-Cabrales, JoaquíN; Morales-Puente, Pedro; Cienfuegos-Alvarado, Edith; Otero, Francisco J. (March 2018). "Diet and habitat of mesomammals and megamammals from Cedral, San Luis Potosí, México". Geological Magazine. 155 (3): 674–684. doi:10.1017/S0016756816000935. ISSN 0016-7568.
  18. ↑ Figueirido, Borja; Pérez-Ramos, Alejandro; Schubert, Blaine W.; Serrano, Francisco; Farrell, Aisling B.; Pastor, Francisco J.; Neves, Aline A.; Romero, Alejandro (2017-12-19). "Dental caries in the fossil record: a window to the evolution of dietary plasticity in an extinct bear". Scientific Reports. 7 (1). doi:10.1038/s41598-017-18116-0. ISSN 2045-2322. PMC 5736623. PMID 29259277.
  19. ↑ "Journal of Cave and Karst Studies Volume 65". legacy.caves.org. Retrieved 2023-11-30.
  20. ↑ DeSantis, Larisa; Schubert, Blaine; Schmitt-Linville, Elizabeth; Ungar, Peter; Donohue, Shelly; Haupt, Ryan (2015-01-01). "Dental Microwear Textures of Carnivorans from the La Brea Tar Pits, California, and Potential Extinction Implications". La Brea and Beyond: The Paleontology of Asphalt-Preserved Biotas: 37–52.
  21. ↑ Baryshnikov, Gennady (1994). Agenbroad, Larry D.; Mead, Jim I. (eds.). The Hot Springs Mammoth Site: A Decade of Field and Laboratory Research in Paleontology, Geology and Paleoecology. The Mammoth Site of Hot Springs, South Dakota Inc. pp. Chapter 16.
  22. ↑ Lauriol, Bernard; Gotthardt, Ruth (2016). Leduc, Heather (ed.). The Ni'iinlii Njik Caves, Northern Yukon (PDF). Government of Yukon. ISBN 978-1-55362-752-4.
  23. ↑ Schubert, Blaine W.; Wallace, Steven C. (August 2009). "Late Pleistocene giant short-faced bears, mammoths, and large carcass scavenging in the Saltville Valley of Virginia, USA". Boreas. 38 (3): 482–492. Bibcode:2009Borea..38..482S. doi:10.1111/j.1502-3885.2009.00090.x. S2CID 129612660.
  24. ↑ Gillette, David D.; Madsen, David B. (1992-03-06). "The short-faced bear Arctodus simus from the late Quaternary in the Wasatch Mountains of central Utah". Journal of Vertebrate Paleontology. 12 (1): 107–112. Bibcode:1992JVPal..12..107G. doi:10.1080/02724634.1992.10011436.
  25. ↑ Redmond, Brian G.; Tankersley, Kenneth B. (10 February 2005). "Evidence of Early Paleoindian Bone Modification and Use at the Sheriden Cave Site (33WY252), Wyandot County, Ohio". American Antiquity. 70 (3): 503–526. doi:10.2307/40035311. ISSN 0002-7316. JSTOR 40035311. S2CID 162034505.
  26. ↑ Trayler, Robin B.; Dundas, Robert G.; Fox-Dobbs, Kena; Van De Water, Peter K. (2015-11-01). "Inland California during the Pleistocene—Megafaunal stable isotope records reveal new paleoecological and paleoenvironmental insights". Palaeogeography, Palaeoclimatology, Palaeoecology. 437: 132–140. Bibcode:2015PPP...437..132T. doi:10.1016/j.palaeo.2015.07.034. ISSN 0031-0182.
  27. ↑ Bocherens, Hervé (2015-06-01). "Isotopic tracking of large carnivore palaeoecology in the mammoth steppe". Quaternary Science Reviews. 117: 42–71. Bibcode:2015QSRv..117...42B. doi:10.1016/j.quascirev.2015.03.018. ISSN 0277-3791.
  28. ↑ Steffen, Martina L.; Harington, C. R. Harington (2010-07-23). "Giant short-faced bear (Arctodus simus) from late Wisconsinan deposits at Cowichan Head, Vancouver Island, British Columbia". Canadian Journal of Earth Sciences. 47 (8): 1029–1036. Bibcode:2010CaJES..47.1029S. doi:10.1139/E10-018.
  29. ↑ Mychajliw, Alexis M.; Rick, Torben C.; Dagtas, Nihan D.; Erlandson, Jon M.; Culleton, Brendan J.; Kennett, Douglas J.; Buckley, Michael; Hofman, Courtney A. (2020-09-16). "Biogeographic problem-solving reveals the Late Pleistocene translocation of a short-faced bear to the California Channel Islands". Scientific Reports. 10 (1): 15172. doi:10.1038/s41598-020-71572-z. PMC 7494929. PMID 32938967.
  30. ↑ Smith, Felisa A.; Elliott Smith, Emma A.; Villaseñor, Amelia; Tomé, Catalina P.; Lyons, S. Kathleen; Newsome, Seth D. (2022-09-27). "Late Pleistocene megafauna extinction leads to missing pieces of ecological space in a North American mammal community". Proceedings of the National Academy of Sciences. 119 (39). doi:10.1073/pnas.2115015119. ISSN 0027-8424. PMC 9522422. PMID 36122233.
  31. ↑ In 1967 Bjorn Kurten of the University of Helsinki wrote a paper, Pleistocene Bears of North America. Kurten said that Arctodus was “…by far the most powerful predator in the Pleistocene fauna of North America”.
  32. ↑ Matheus, Paul E. (2003). Locomotor adaptations and ecomorphology of short-faced bears (Arctodus simus) in eastern Beringia. Yukon Palaeontologist, Gov't. of Yukon. OCLC 243520303.
  33. ↑ Emslie, Steven D.; Czaplewski, Nicholas J. (1985-11-15). "A new record of giant short-faced bear, Arctodus simus, from western North America with a re-evaluation of its paleobiology". Contributions in Science. 371: 1–12. doi:10.5962/p.226835. S2CID 133986793.
  34. ↑ 34.0 34.1 Steffen, Martina L.; Fulton, Tara L. (2018-02-01). "On the association of giant short-faced bear (Arctodus simus) and brown bear (Ursus arctos) in late Pleistocene North America". Geobios. 51 (1): 61–74. Bibcode:2018Geobi..51...61S. doi:10.1016/j.geobios.2017.12.001.
  35. ↑ Paul, Matheus (2001). "Pleistocene carnivores and humans in eastern Beringia: did short-faced bears really keep people out of North America?". In Gerlach, S. Craig; Murray, Maribeth S. (eds.). People and Wildlife in Northern North America: Essays in honor of R. Dale Guthrie. BAR Publishing. pp. 79–101. doi:10.30861/9781841712369. ISBN 978-1-4073-5292-3.
  36. ↑ Salis, Alexander T; Bray, Sarah C E; Lee, Michael S Y; Heiniger, Holly; Barnett, Ross; Burns, James A; Doronichev, Vladimir; Fedje, Daryl; Golovanova, Liubov; Harington, C Richard; Hockett, Bryan; Kosintsev, Pavel; Lai, Xulong; Mackie, Quentin; Vasiliev, Sergei; Weinstock, Jacobo; Yamaguchi, Nobuyuki; Meachen, Julie; Cooper, Alan; Mitchell, Kieren J (3 September 2020). "Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge". bioRxiv 10.1101/2020.09.03.279117.
  37. ↑ Pigati, Jeffrey S.; Springer, Kathleen B.; Honke, Jeffrey S.; Wahl, David; Champagne, Marie R.; Zimmerman, Susan R. H.; Gray, Harrison J.; Santucci, Vincent L.; Odess, Daniel; Bustos, David; Bennett, Matthew R. (2023-10-06). "Independent age estimates resolve the controversy of ancient human footprints at White Sands". Science. 382 (6666): 73–75. Bibcode:2023Sci...382...73P. doi:10.1126/science.adh5007. ISSN 0036-8075. PMID 37797035. S2CID 263672291.
  38. ↑ Schubert, Blaine W. (2010-04-15). "Late Quaternary chronology and extinction of North American giant short-faced bears (Arctodus simus)". Quaternary International. Faunal Dynamics and Extinction in the Quaternary: Studies in Honor of Ernest L. Lundelius, Jr. 217 (1): 188–194. Bibcode:2010QuInt.217..188S. doi:10.1016/j.quaint.2009.11.010.
  39. ↑ Stuart, Anthony John (May 2015). "Late Quaternary megafaunal extinctions on the continents: a short review: LATE QUATERNARY MEGAFAUNAL EXTINCTIONS". Geological Journal. 50 (3): 338–363. doi:10.1002/gj.2633. S2CID 128868400.
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