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Extinct American Lion (Panthera atrox) Fact Sheet: Reproduction & Development

extinct American Lion (Panthera atrox)

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.

Life Stages

Growth patterns

  •  Juvenile Panthera atrox have canine teeth not yet used to kill prey; they feed on adults' kills
    • The two halves of the lower jaws are not yet reinforced at the midline symphysis to withstand the force of a killing bite (Therrien 2005)
  • Growth rates for canine teeth of Panthera atrox were about 2-3 mm (.08 to 1.2 in)/month (Feranec 2004)


Mortality and extinction

  • No know predators on adult American Lions
  • Accidents, fights, hunting by Paleolithic humans
  • Extinction of Panthera atrox around 13,000 years ago

Page Citations

Feranec (2004)
Therrien (2005)

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