Related Biomes
American Lion
American lion, Panthera atrox
Commonly known as the American lion, the relationship between Panthera atrox and other big cats around the world has been difficult to classify. Scientists have identified similarities between this cat and modern lions, tigers and jaguars, as well as close similarities with the extinct European cave lion. Recent studies comparing the physical attributes of P. atrox with those of the other big cats have indicated that it may have been a giant jaguar rather than a New World lion (Christiansen 2008; Christiansen and Harris 2009). However, a new ancient DNA study (Barnett et al. 2009) indicates that P. atrox was closely related to both the cave lion (Panthera spelaea) and the modern lion (Panthera leo) and suggests that they were less closely related to jaguars.
Mounted skeleton of an american lion, Panthera atrox, on display at the George C. Page museum at the La Brea Tar Pits in Los Angeles. Photo by Ed Bierman, and used by permission under the Creative Commons Attribution 2.0 Generic License.
Length: 1.6-2.5 m (5-8 ft); Martin 1984
Weight: males: 200-300 kg (440-660 lbs); females: 125-175 kg (275-385 lbs); Christiansen and Harris 2009, Wheeler and Jefferson 2009
Physical Description:
Panthera atrox was one of the largest true cats (the family Felidae) to ever live. Compared to other North American Ice Age cats, P. atrox had relatively long, slender limbs. Indeed, this cat looked very similar to the modern lion, only bigger and with longer legs. Significant sexual dimorphism has been established for this species and males were up to 1.40 times larger than females, on average (Wheeler and Jefferson 2009). As with all modern cats, the extinct American lion was a conical-toothed cat. Its upper canines were round in cross-section forming a slightly curved cone. They fit behind the lower canines rather than protruding out of its closed mouth (Martin 1980). P. atrox also had retractable claws.
American lion remains are often recovered in association with animals that preferred open habitats, such as steppe tundra and mountain grasslands (Gilbert and Martin 1984). In addition, researchers have pointed to the length of their legs as evidence that they were well-suited to running and hunting over open terrain, and thus would prefer open habitats over forested ones. Of course, this interpretation is based, in part, on the idea that P. atrox was a lion and shared behavioral traits with modern lions (Christiansen and Harris 2009; e.g., Kurtén and Anderson 1980, Wheeler and Jefferson 2009). The recovery of numerous P. atrox remains from the Rancho La Brea tar pits, which were located within a woodland setting, raises questions about this animal's habitat preference (Christiansen and Harris 2009).
As with other cats, the American lion was an obligate carnivore, which means that it only ate meat. According to a recent bone chemistry study, this cat probably preferred larger mammals, such as bison, American horse, or juvenile mammoths and mastodons (Coltrain et al. 2004).
There has been some disagreement about the sociality of the American lion. Researchers who believe that this animal fits within the lineage of extant lions argue that this animal had the African lion's social propensity and therefore lived in groups (e.g., Wheeler and Jefferson 2009). On the other hand, researchers who place the American lion within other big cat lineages argue that it was a solitary animal (e.g., Christiansen and Harris 2009). Unlike other some other large cats where family groups are preserved in the fossil record (e.g., Homotherium serum, Friesenhahn Cave, Texas), multiple individuals of P. atrox from a single locality is an extremely rare occurrence.
The American lion was widely distributed in North America during the late Pleistocene and has been recovered from sites ranging from southern Mexico (Montellano-Ballesteros and Carbot-Chanona 2009) to southern Canada (Barnett et al. 2009). It should be noted that until recently the Panthera remains recovered from the Yukon and Alaska were classified as P. atrox (e.g., Kurtén and Anderson 1980); however, ancient DNA studies have demonstrated that these animals were genetically different from their cousins south of the ice sheets, and they have been reclassified as cave lions (P. spelaea; e.g., Barnett et al. 2009).
The American lion went extinct towards the end of the late Pleistocene, along with many other large mammals in North America. A recent radiocarbon date of 11,355 +/- 55 (13,100-13,300 cal BP) was obtained on bone collagen from a specimen recovered from a site in Edmonton, Canada, providing the youngest direct date for this species, and a good estimate of when it went extinct (Barnett et al. 2009).
Although no positively identified American lion remains have been recovered from late Pleistocene-aged localities within the Midwest, we would expect to find these animals in the more open habitats of the western parts of the region, particularly at sites in western Iowa or northwestern Missouri. Fossilized cat tracks recorded at Berome Moore Cave and Cat Track cave in eastern Missouri have been tentatively identified as American lion tracks.
- "Atrox" means cruel or frightful in Latin
- Panthera atrox is estimated to have been 25% larger than the modern lion (P. leo) on average, and the largest specimens of P. atrox may have been the largest conical-tooth cats ever
Barnett, R., Shapiro, B., Barnes, I., Ho, S., Burger, J., Yamaguchi, N., Higham, T., Wheeler, H. T., Rosendahl, W. Sher, A., Sotnikova, M., Kuznetsova, T., Baryshnikov, G. F., Martin, L. D., Harington, C. R., Burns, J., Cooper. 2009. Phylogeography of lions (Panthera leo ssp.) reveals three distinct taxa and a late Pleistocene reduction in genetic diversity. Molecular Ecology 18: 1668–1677.
Christiansen, P., Harris, J. 2009. Craniomandibular Morphology and Phylogenetic Affinities of Panthera atrox: Implications for the Evolution and Paleobiology of the Lion Lineage. Journal of Vertebrate Paleontology 29(3):934-945.
Christiansen, P. 2008. Phylogeny of the great cats (Felidae: Pantherinae), and the influence of fossil taxa and missing characters. Cladistics, 24, 1–16.
Coltrain, J. B., J. M. Harris, T. E. Cerling, J. R. Ehleringer, M. Dearing, J. Ward, and J. Allen. 2004. Trophic level relationships among Rancho La Brea fauna and their implications for the paleoecology of the late Pleistocene based on bone collagen stable carbon and nitrogen isotope chemistry. Palaeogeography, Palaeoclimatology, Palaeoecology 205:199–219
Gilbert, B., Martin, L. 1984. Late Pleistocene fossils of Natural Trap Cave, Wyoming, and the climatic model of extinction. In P. Martin, and R. Klein, eds, Quaternary Extinctions: A Prehistoric Revolution. University of Arizona Press, Tucson pp. 138 -147.
Kurtén, B, Anderson, E. 1980. Pleistocene Mammals of North America. Columbia University Press, New York.
Martin, L. D. 1980. Functional Morphology and the Evolution of Cats. Transactions of the Nebraska Academy of Sciences 9: 141-154.
Martin, Paul S. 1984.Quaternary Extinctions. Tucson, Arizona: University of Arizona Press.
Montellano-Ballesteros, Marisol and Gerardo Carbot-Chanona. 2009. Panthera leo atrox (Mammalia: Carnivora: Felidae) in Chiapas, Mexico. The Southwestern Naturalist 54(2):217-222.
Wheeler, H. T., Jefferson, G. T. 2009. Panthera Atrox: Body Proportions, Size, Sexual Dimorphism, and Behavior of the Cursorial Lion of the North American Plains. In Papers on Geology, Vertebrate Paleontology,a nd Biostratigraphy in Honor of Michael O. Woodburne, edtied by Albright, L.B. III, pp. 423-444. Museum of Northern Arizona Bulletin 65, Flagstaff, AZ.
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