Re: Warm-Blooded debate

[Jeffrey Martz <martz@holly.ColoState.EDU>]

> I thought that Komodo dragons 'get by without starving' because there is a
> lack of large warm-blooded predators to compete with in their environment.
> They can lie in wait for food to walk by, and then run very fast for a short
> period of time.

     If all or most theropods were ectotherms, they would not have had to
compete with warm blooded predators either.  The point I was trying to
make is that the ectothermic Komodo dragons are effective at taking down
supposedly much more active, and frequently very large, endothermic prey.
     In regards to Utahraptor being designed to be active, keep in mind
the claws and teeth and "agility" is only needed for those very brief
periods of attacking and killing.  I doubt they had reason to spend 90% of
thier day running around doing flips and kung-fu kicks anymore then modern
predators, endotherms or ectotherms.  
      As far as sprawling being linked to ectothermy and vertical gait
being linked to endothemy, I find it interesing that no one (as far as I
know) has suggested upright stance may actually be linked to bipedality.
It may be more convenient to have the legs positioned underneath the body
if you are only going to support your weight on two legs.  Yes, I am aware
of the "Jesus Christ" lizard, as well as many other lizards that can run
around with sprawled back legs, but early dinosaurs may have had more to
worry about stance-wise since they were relatively large (by lizard
standards) animals.  Yes, I am also aware that quadrapedal dinosaurs had
had at least vertical limbs, but this may have been a feature inherited
from upright posture/bipedal ancestral dinosaurs, and may have allowed
them thier large size (the "pillars" of sauropod legs for example).
Upright posture may be more closely liked to bipedality &/or relatively
large size then to endothermy.  Any comments?    

LN Jeff
O-