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Extinct American Lion (Panthera atrox) Fact Sheet: Physical Characteristics

extinct American Lion (Panthera atrox)

How Do We Know This?

Study of fossil bone and tooth anatomy yields much exact information about placement and strength of muscles, tendons, ligaments, nerves, and blood vessels. In rare cases, skin and hair impressions or actual skin or hair is preserved. Body weight is more difficult to gauge because fat leaves no impression on the skeleton. A few extinct Pleistocene lions were painted by observant paleolithic artists.

Physical Characteristics

Body measurements

Weight* large male up to 235 kg (518 lb) large female up to 175 kg (386 lb)
Length 1.6 - 2.5 m (5.3 - 8.2 ft)
Tail Length 0.5 - 0.8 m (1.7 - 2.7 ft)

*estimated to be 25% larger than modern lions

Sources: Anderson (1984), Shaw (2005)

General Appearance

General Description

  • Very similar to modern lions, but larger, with relatively longer and stronger legs
  • Larger brain, relative to size, than seen in the Smilodon that lived at the same time


  • Used exclusively for meat-eating
  • Males' canine teeth 20% larger than females' (Kurtén 1985)
  • Strength of bite focused at canines (Therrien 2005)


  • Cro-Magnon people in France painted detailed portraits of lions on cave walls around 30,000 years ago.
    • Lions were depicted without manes (Clottes 2003)
    • Observant artists even drew black dots at base of the lions' whiskers (Turner 1997)
  • Manned lions may have replaced earlier mane-less lions at the end of the Pleistocene (Yamaguchi 2004)
  • Not known whether the American Lions were spotted (leopard-like) or more uniform in color

Sexual Dimorphism

  • Males consistently larger than females; males have larger canine teeth than females (Yamaguichi 2003)
  • Not known with certainty whether extinct lions had manes, which in modern lions is an important sexual signal (Yamaguichi 2003)
  • Level of sexual dimorphism similar to or slightly greater than in modern P. leo (Meachen-Samuels & Binder 2009)

Other Physical and Physiological Characteristics

  • Flexible and powerful front limbs
    • Bending strength of Panthera atrox forelimbs much greater than modern lion's and similar to a brown bear's (Anyonge 1996)
    • These traits helped them to subdue their prey before inflicting a powerful canine killing bite
    • To some degree all cats have these traits, but they are extreme in several large Pleistocene felids
  • Like all cats, retractable claws

Extinct American Lion

female Extinct American Lion

Artist's representation of an extinct American lion.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Page Citations

Anderson (1984)
Anyonge (1993)
Clottes (2003)
Kurtén (1985)
Kurtén and Anderson (1980)
Macdonald (2001)
Meachen-Samuels and Binder (2009)
Owen (2002)
Shaw (2005)
Therrien (2005)
Yamaguchi (2004)

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