American Lion, Panthera atrox
November 2008

SDZ Global Logo

©San Diego Zoo Global, all rights reserved

*How Do We Know This? Like living animals, fossil remains of once-living animals are
classified and grouped according to their relationships to each other and to their ancestors.

(Barry 1987) (Burger et al 2004) (Leidy 1853) (Turner 1987 & 1997)
(Wozencraft 2005)

Describer (Date): Leidy 1853 for Panthera atrox. American Philosophical Society Transactions 10:319-321

Kingdom: Animalia
    Phylum: Chordata
        Class: Mammalia
             Order: Carnivora
                Suborder: Feliformia (True cats plus hyenas, mongooses, civets)
                    Family: Felidae (Lion, tiger, jaguar, leopard, cougar, cheetah, lynx, caracal, domestic cat and many fossil taxa)
                          Subfamily: Machairodontinae (extinct saber-toothed cats)
                          Subfamily: Felinae (cheetah, lynx, bobcat, caracal, puma, fishing cat, ocelot, margay, jaguarundi, serval, domestic cat)
                          Subfamily: Pantherinae (leopard, lion, tiger, jaguar, snow leopard, clouded leopard)
                                 Genus: Panthera
                                         Species: Panthera atrox (extinct)

Taxonomic History and Nomenclature

*How Do We Know This? Paleontologists use knowledge of the earth's rocks, global
plate tectonic movements, ancient ecosystems, and the chemical process of fossilization
to make sense of fossil distribution patterns and ancient habitats.

(Barry 1987) (Cerling et al 1998) (Gilbert & Martin 1984) (Jefferson2001) (Kurtén 1968)


*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.

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

Estimated Body Weight: Large male up to 235 kg (518 lbs); large female up to 175 kg (386 lbs); estimated to be 25 % larger than modern lions. (Anderson 1984)
Head and Body Length: 1.6 - 2.5 m (5.3 - 8.2 ft) (Shaw 2005)
Tail Length: .5 - .8 m (1.7 - 2.7 ft) (Shaw 2005)

General Description
Teeth Pelage Sexual Dimorphism Other Physical Characteristics

*How Do We Know This? Since direct observation of a fossil animal's behavior isn't
possible, paleontologists use comparison and contrast with living animals for guidance.
Tracks can sometimes reveal further clues to behavior. At a fossil site, the mix of plant and animal
species gives clues to the ecosystem of that time and place.

(Jefferson 1992, 2001) (Van Valkenburgh & Hertel 1993)
(Yamaguchi et al 2004)

Social Life
  Interspecies Interaction

*How Do We Know This? Clues to fossil mammals' diets come from teeth,
skull shape and the positions and strength of major jaw muscles, from fossilized
dung and guts, from oxygen isotopes in bone and teeth, and from diets of similar
modern animals.

(Guthrie 1990) (Martin & Klein 1984) (Owen 2002) (Therrien 2005) (Van Valkenburgh and Hertel 1993)

*How do We Know This? Clues to stages of development in a growing animal come
from tooth replacement patterns and timing of suture closure in skull and limb bones.

(Feranec 2004) (Therrien 2005)

Life Stages/Growth Patterns
Mortality and Extinction

*How do We Know This? Abnormalities in fossil bones may show
evidence of arthritis, cancer, nutritional stress, fractures and more.

(Beebe & Hulland 1988) (Van Valkenburgh & Hertel 1993) (Whitmore & Foster 1967)

Important Web Resources (including where to view fossils in museums):

©2009 San Diego Zoo Global. Disclaimer: Although San Diego Zoo Global makes every attempt to provide accurate information, some of the facts may become outdated or replaced by new research findings. Questions and comments may be addressed to

Return to the Fact Sheet Index