American Lion (Panthera atrox)

[tigerluver]

Whenever estimating mass, I prefer bones and body length over shoulder height. Shoulder height is often deceptive, tall quadrupeds could have shorter bodies and thus shoulder would skew mass estimation. This applies intraspecifically as it does interspecifically. 

Another fact on the prehistoric lions is that they are much more robust. For instance, artifically scaling these humeri to the same length shows the robusticity difference:

*This image is copyright of its original author

Unfortunately the photo of P. atrox is a diagram (accurate one nonetheless) and there are even more robust specimens on record. 

Another fact about anterposterior robusticity, especially at the humeral and femoral sockets, is that it brings reason to say the specimen was proportionately longer for its height. If the head of these bones is anteroposteriorly wider, then the girdles should be anteroposteriorly longer, and thus the entire animal should be longer. These lions had some wide, wide femoral and humeral heads and thus my predicted body lengths. Reply