Re: The absurdity, the absurdity (was: Cooperating theropods?)

[Jack <jconrad@lib.drury.edu>]

On Sat, 4 Apr 1998, Larry Dunn wrote:

> As to entertaining the possibilities: it's also possible that 
> dromaeosaurs ate only each other, isn't it?  Isn't there in fact better 
> evidence to indicate that theropods preyed upon each other than that 
> they preyed upon herbivores?  I mean, these *were* animals so different 
> from what's around today and all.  So are you willing to entertain that 
> hypothesis?

Certainly.  Theropods are known to have attacked each other, there 
are bones with wounds etc.  However, we have *evidence* suggesting that
theropods (many theropods, excuse me) ate other animals (hadrosaur and
ceratopsian bones with theropod tooth marks or broken theropod teeth in
them).  Dromie teeth are found with tenontosaur skeletons.  There, the
hypothesis has been entertained and solid evidence presented to contradict
it.  

This differs from the dromie killing the tenontosaur scenario where we
have no conclusive evidence either way.  Therefore, the idea of dromies
*possibly* hunting tenontosaurs should be entertained.  

> My point being that, upon hearing this, many would rush to say that 
> vertebrate predators don't make a living eating each other and then fill 
> in all the perfectly good reasons why they don't.  We can't analogize to 
> extant vertebrate behavior when it's convenient and then ignore it when 
> it keeps hundred pound Deinonychus off of one-ton Tenontosaurus's back.

As I described above, there is no reason to analogize behavior in this
scenario.  We already know that dromies ate other animals.  

> I'm trying to understand how you can see the premise being the same.  
> Evidence that animal A ate animal B does not in any way indicate or even 
> suggest that animal A first killed animal B.

The original premise was that because we have evidence that future
paleontologists will have no evidence that owls killed the small mammals
discovered in their coprolites, just as we have no way to prove if
_Deinonychus_ killed tenontosaurs.  There will be no evidence that lions
killed cape buffalo or elephants, but still owls kill small mammals and
lions kill buffalo.  Will future paleontologists entertain these
possibilities?

> And then the one that weighs the most should be accepted as the most 
> likely hypothesis (not the sexiest but pretty improbable one).

Likely as compared to bobcats, lions, bears, tigers, or no extant
predator?

jc