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Re: [Re: Cheekless and lipless dinosaurs...]

owner-dinosaur@usc.edu wrote:
> Ralph Miller III 1/3 wrote:


> <One problem with the lipless model is that the tyrannosaurid would

> lack the means to seal out bacteria, and disease and infection could

> find easy entry into the animal. On the other hand, monitor lizards

> make good use of oral bacteria when they bite into their prey,

> infecting the bitten animal with bacteria which will kill the prey if

> the wound itself does not.>


>   This is a perfect example of a symbiotic relationship: the bacteria

> feed on whatever the monitor feeds on, and the monitor gets a quicker

> meal. Also good example for a poikilothermic reptile adapting to

> homeothermic meals -- faster killing method for a slow animal

> (relatively speaking -- monitors can move very quickly when all warmed

> up).


> <So a tyrannosaur might have developed similar immunities (to the

> monitor's).>


>  Why would a theoretically tachymetabolic warm-blood like a

> tyrannosaur need to use bacteria to facilitate a kill? Certainly the

> size of the prospective meal (a trike, say) would have a body mass so

> great that any bacteria delivered in a bite would have a real hard

> time of causing enough infection to injure (much less kill) breakfast.


> ==

> Jaime A. Headden


It makes perfect sense. What predator wouldn't want a little extra insurance
in the event the prey animal gets away. 

And think about it, a T.rex is not going to make a couple of little
lacerations. We are talking large chunks being ripped out. Regardless of mouth
bacteria, the size of the wound would cause enough trauma to do the trick.

Oh and on a side note, can we please refrain from the warm-blood = good
cold-blood = bad belief.

An adult nile monitor is more active than an adult lion. And it has nothing to
do with endothermy/ectothermy.

Oh and please note, I realized that you stated that monitors are fast, but the
point is always getting implied. And not just this post, but many others on
this list.

I mean once in awhile it's is stated that there are advantages to ectothermy,
but the unanimous ideal is that deinosaurs cannot be ectotherms.

Sorry I usually don't get all worked up over these things.

Archosaur J


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