Re: Carnivore Energetics: Why Are Lions Not As Big As Elephants?

[MICHAEL HABIB <habib@jhmi.edu>]

"so my question is if that's the only reason, why couldn't mammals do the same? 
Which is to say I think there is more to it than just the metabolic rates of 
the predator, which seems to be what
everyone else is saying."


A good question and a good point.  

One item to note is that there are really multiple questions embedded in the 
"size discrepancy" issue.  The question of why extant mammalian predators are 
not larger than they are is a separate question from why theropods reached the 
sizes that they did.  

For starters, even without constraints of physiology, behavior, or life 
history, would we expect modern mammalian carnivores to reach large theropod 
sizes?  Is there any reason that we should expect that they would?  Or, to put 
it another way: what is our null hypothesis for this scenario?

Cheers,

--Mike H.