The Cave Lion (Panthera spelaea and Panthera fossilis)

[tigerluver]

That was really well put @GrizzlyClaws . Now we already seem to have a sense as to why Smilodon populator and P. t. soloensis got so big (when they moved in they had become the biggest feline, unlike their relatives in the north (S. fatalis to P. atrox and P. t. acutidens to P. spelaea). That leaves the question as to why was the lion lineage so large early. Remember the P. shawi humerus? That was as bigger, if not bigger, than the largest P. atrox we have on record. Add to that, the sample size of P. shawi pales in comparison to that of P. atrox, so probability says P. shawi may have been gigantic. What exactly happened between the migration of the lion lineage all the across Asia into Africa that triggered the gigantism that would stay in the lineage for over two million years? 

What we need is to find the missing links across the huge migration route of the lion lineage. We know that the lions that are popular today all can be traced back to Africa. Did the lineage experience gigantism then? Or perhaps, the size started increase on the way to Africa while still in Asia. Many scenarios, yet not really any fossils to refer to unfortunately. Reply