How certain are we that the extinct North American was a "lion" and not a "tiger"?  It has always seemed strange to me given that tigers are found right over in Siberia and lions are a little further away in terms of distribution and I am assuming that it would be tough to tell the difference between the two from fossil material (as even us casual observers can tell that both species show a wide range of variation and are capable of interbreeding).  Thanks in advance.

Hi Felipe,

the terms "lion" and "tiger" can be used quite loosely - "Sabre-toothed tigers" for instance are not tigers in any real sense of the word, they're just big felids so "tiger" is used to describe them.

In the case of the American lion however, there is genetic evidence to suggest that it is actually closer to a lion:
http://www.uni-mainz.de/FB/Biologie/Ant … 202004.pdf

Lions have/had a much greater range than tigers, possibly because they are/were less tied to forests. In the Pleistocence it would have been difficult for forest restricted tigers to spread into America, but the more adaptable lions would be better able to cross over the Bering Land Bridge.

In the case of the American lion however, there is genetic evidence to suggest that it is actually closer to a lion

This study (Burger et al. 2004) looked at genetic materials from the European cave lion, Panthera leo spelaea and not the North American lion Panthera leo atrox. According to their study, the European cave lion comes out as the sister taxon to all modern lion (Panthera leo) subspecies. The tiger (Panthera tigris) on the other hand split off from the (jaguar P. onca + leopard P. pardus+ lion P. leo) clade first. Thus, at least with the European cave lion, it is much closer to the lion than it is to the tiger. Morphological taxonomy seems to suggest a closer affinity of the American lion with the lion than with the tiger.

However, having said that, I'm not sure if these fossil "lions" can be confidently assigned as subspecies of P. leo. As you may know, the biological species concept is extremely difficult to apply to fossil taxa. As a palaeontologist, I would be inclined to treat both the European cave lion and American lion as separate species for now, i.e. P. spelaea and P. atrox respectively. In other words, the American lion would be another big cat that's probably quite closely related to the lion.

Last edited by Manabu Sakamoto (1st Apr 2008 01:12:20)

Ah yes, thanks Manabu - I clearly lost the plot there!

I would also agree that from a morphological perspective there are real problems with assigning sub-species based on skeletal material - even telling a tiger from a lion can be difficult (as Manabu and I well know).

Manabu,

Lions are more closely related to leopards and jaguars than to tigers?  Really?

This isn't an April 1 post, is it?

>Mike,

This isn't an April 1 post, is it?

Hehehe, actually no. It depends on whose phylogeny you trust, but Johnson et al.'s (2006) molecular phylogeny is as follows:

{{Panthera leo (lion) + Panthera onca (jaguar)} + Panthera pardus (leopard)} + {Panthera tigris (tiger) + Panthera (Uncia) uncia (snow leopard)}

So, lion is sister to jaguar, leopard is sister to (lion+jaguar), (lion+jaguar+leopard) clade is sister to (tiger+snow leopard) clade. Further, the clouded leopard Neofelis is sister to this Panthera clade.

Burger et al. (2004) didn't include the jaguar in their study but their result is in agreement that the lion is closer to the leopard than it is to the tiger. Their phylogeny is pretty much (((lion+European cave lion)+leopard)+tiger). I've never seen a phylogenetic analysis including the North American cave lion P. atrox but I think the consensus is that it is closer to the modern lion than it is to the tiger, and presumably even closer to the lion than the leopard or the jaguar...


>Paolo - yes, it was fun trying to work out the differences between lion and tiger skulls and I'm happy we eventually figured it out!

Last edited by Manabu Sakamoto (2nd Apr 2008 16:40:44)