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

[Chris Campbell <sankarah@ou.edu>]

Larry Dunn wrote:
> 
> From: Wile E 81 <WileE81@aol.com>
> 
> > No, not all It is healthy and educating to argue the possibilities.
> > Im simply saying that  since there is no possible way at present to 
> > prove either hypothesis, it makes sense to optimistically approach 
> > all possibilities and accept the fact that there is no conclusion 
> > that can be made as of yet and that  your opinions are as fabricated 
> > as any other .
> 
> In the face of this lack of knowledge, how shold we proceed?  Optimism
> or pessimism should not be relevant.  Likely or unlikely should.
> 
> We know that, in all likelyhood, deinonychus was much less intelligent
> than modern pack hunters.  We know that only the most intelligent
> animals hunt in cooperation with each other.  So what can we safely
> surmise about the hunting techniques of theropods?

Larry, we don't know any of this.  Modern avian studies show that what
we thought we knew about intelligence isn't really true at all, which in
turn shows that dinos might (emphasis on the might, here) have been much
more intelligent than their brain mass might indicate.  Though they were
still probably less intelligent than modern mammalian carnivorous pack
hunters, they may well have had the brains needed to act in social
groups.  

Second, we know flat out that even such simple things as spiders can
engage in coordinated, pack tactics in an effort to bring down prey;
this shows quite conclusively that having the smarts of a dog or lion
isn't necessary for pack coordination.  All that's needed is some means
of communication (which most animals have) and some means of
coordination, which would require very simple neural hardware.

None of which says anything about Deinonychus, of course; it may have
hunted in packs, it may not have.  The statistics say it probably
didn't, but if any predatory dino is a good candidate it's Deinonychus.
 
> If your answer is "nothing, because dinosaurs were not like any animals
> that exist today, etc." then we need to stop discussing their behavior
> at all, because we have no other references at all except the fossil
> record and, as you've seen, people disagree even about the Tugrugeen
> fossil -- and good luck finding a more thorough fossil example of
> interspecies conflict than THAT!

It's a beautiful example of conflict; who was attacking whom, and for
what reason, is highly debatable.
 
> >  Unless you have evidence that weighs so heavily that It would stifle
> >the debate for all time,, then your  "Dimwitted Deinonychus as a solitary
> >small game hunter"   hypothesis Is as you said ... A Fantasy .
> 
> Why, I've never said any such thing.  Both "dimwitted" and "small game
> hunter" are relative terms.  I've never passed *judgment* on the
> animals; I'm just trying to find the most reasonable interpretation of
> their lifestyle based on the fossil record and on modern cognates.

Then stick with things not easy contradicted by modern fauna.  Examples
can be found of modern fauna coordinating their activities with very
little brain matter, so arguing they're (Deinonychus) not bright enough
to hunt like this won't work.  Examples can be found of modern fauna
taking animals up to ten times their size, so that goes out the window. 
Arguments can be made either way based on physical capabilities.  Fact
is, there's no reason Deinonychus couldn't hunt as a pack predator. 
There's no reason to think it did, no evidence whatsoever to support it
-- but the argument claiming it didn't have the mental and/or physical
capabilities to do it is false.
 
> >Your saying that deinonychus could not take down a Tenontosaur based on
> >the fact that that you could not assertain this from looking at the fossil
> >record.  And I agree there is nothing to point toward D preying upon T, 
> >but It also does not show that it didnt.
> 
> But "prove it isn't" can't be a valid argument here.  Otherwise you
> could propose that Tyrannosaurs were actually around in the Triassic.
> It'd be hard to prove they weren't.

It's true that the burden of proof is on those making a case for pack
hunting, but note that's it's impossible to prove predation of any sort,
by any extinct animal, at any time.  The only thing we can do with any
reliability is determine what seems reasonable in light of the weaponry
a given animal possessed.  Deinonychus certainly had the weaponry needed
to bring down juvenile Tenontosaurs.  It probably could do quite well
alone, actually, though if (big if) it hunted in packs is could take
larger prey.  

Now, the question's been asked, "why would they hunt in packs if they
could hunt by themselves just as well?"  This is a good question, and
I'd direct the reader's attention to India in response.  Here you'll
find lions and tigers with diets which overlap a fair amount, with one
hunting in prides and the other hunting alone.  They live, however, in
different environments, and conduct themselves accordingly.  My point is
that if (again, big if) Deinonychus hunted in packs it might have done
so so that it could move into a different environment.  There are many
other possible reasons, of course; I just give the above as one
possibility.
 
> >You use its small brain size to support your view
> >fairly frequently, which we all know Is not always an accurate measure
> >of intelligence.  Many of the claims you make are severely unfounded 
> >and highly questionable.
> 
> Well, there tends to be a direct correlation between intelligence and
> relative size of the brain, right?  

No, not right.  If shark studies indicate they might be as bright as
some birds (and they do) and bird studies indicate they might be as
bright as some mammals (presumably not the same birds being used, here;
lots of variety in aves), they the correlation becomes quite suspect. 
How does one respond to an African Grey Parrot who's a bright as a chimp
and has a brain the size of a grape (maybe plum?).  That correlation
works within a given group, not between them.  Even within a group it's
suspect; see dolphins.  The brain can be constructed in various ways,
and that impacts how intelligent a species may be.

>Why make an exception for dromaeosaurs because it would tend to discourage 
>notions of a certain exciting proposed behavior?

See above.  There are dozens of exceptions running around already.  We
shouldn't condemn on the basis of a generalization.
 
> I've attempted to base my discussion on fairly commonly known dinosaur
> science and on observation of animal behavior.  

Ammend that to "mammal behavior."  Actually, "common assumptions about
wolf and lion behavior" might be most accurate.  What you're arguing
isn't consistent in extant animals; no reason to think it would be in
dinosaurs.

>I don't think I've strayed from that path.  What are the claims of the 
>pack-hunting enthusiasts based on?  So far, all I've seen is the creation of
>increasingly elaborate scenarios utterly alien to our understanding of
>animal behavior.

No, they're not.  They might be alien to your understanding of animal
behavior, but don't generalize your assumptions to include all the
arachnologists and icthyologists and ornithologists out there who see it
as quite feasible.  There is nothing to support the theory of pack
hunting in dromaeosaurs -- however, that doesn't mean by any stretch of
the imagination that it's not possible.  So why bother with it?  Because
if any dino did engage in pack hunting, dromies would be it.  They're
the right size (relative to other dinos), fairly bright (relative to
other dinos), and armed in such a manner that they could conceivably
take prey much larger than they would need alone.  This makes pack
hunting very possible with these animals, whereas it's much less so with
other therapods.  This, then, is why I think the notion is so popular. 
Social animals attract attention, so the notion of social dinos is a
very appealing one.  A notion without support, but so is most anything
behavior related among dinos.
 
Chris