Freak Felids - A Discussion of History's Largest Felines

[tigerluver]

Cranially, P. leo is very similar to the cave lions. Mandible:skull length ratio and nasal aperture structure are nearly identical. P. spelaea (the form present in the late Pleistocene) has a wider skull and P. fossilis (the form present in the early-middle Pleistocene) a thinner one (tentatively, P. fossilis has a uniquely shaped cranium thus its skull proportions don't exactly compare perfectly), however. The mandible shapes in the cave lion are also distinct from P. leo. There are dentition proportion and shape differences as well across P. leo, P. fossilis, and P. spelaea. P. atrox is closest to P. fossilis in its cranial characteristics buts still has some advanced differences. 

The split probably occurred once the African stem group that migrated to Eurasia was isolated, either by geographic distance or rising of sea levels I assume. Perhaps the lion went into Europe the same way homonids did. 

From Muttoni et al. (2010):

*This image is copyright of its original author

Human migration into Europe during the late Early Pleistocene climate transition Reply