"PACK-HUNTING" THEROPODS

[franczak@ntplx.net (Brian Franczak)]

Larry Dunn wrote:

> I assume that the predation hypothesis suggests a struggle to kill the
> Tenontosaur, with several Deinonychus dying in the process.
>
> Isn't the patent absurdity of this obvious?
>
> How often to pack-hunting vertebrates attack a prey animal and lose
> *three* of their number in the process?  They may lose one but that
> would be a fluke.  In the *highly* unlikely event that they accidentally
> attack an animal that is too tough for them (hunting vertebrates tend to
> very carefully choose their prey), they'd certainly back away and cut
> their losses.  The object of the game is to survive, not just to kill.
> Pack hunters just do not attack an animal that will kill multiple pack
> members.
>
> This hypothesis seems to remove dinosaurs from the realm of reality and
> surrender them to the fantasy of antediluvian "savage monsters" which we
> now know that they certainly were not.
>
> So unless the Tenontosaur went postal (upset with comments about his
> "big tail") and started hunting Deinonychus, the whole scenario just
> seems counterintuitive to me.
>
> The only other rational explanation I can see is that there was a fight
> at the found carcass (theropods certainly seem to have been rough with
> each other) leading to the deaths of certain animals.

What he said.

Remember when sauropods were pretty much restricted to having to live in
the water because they couldn't support their weight on dry land, and
needed the water to buoy up their massive bodies? As ludicrous as that
sounds in the light of modern knowledge, so too will we someday look at the
notion of "pack-hunting" theropods.

Let's address a couple of the issues that have been raised:

1) Cooperative hunting in extant birds...
In a word: irrelevant. Modern birds exhibit a wide variety of social
behaviors (some of which may be applicable in theorizing about theropod
behavior), but they do *not* band together to bring down prey *larger than
themselves*. The behavior seen in Bay-Winged (Harris) Hawks is therefore
not applicable to this argument. Bay-Winged Hawks do not take down prey as
large as javelinas or small deer. Likewise, pelicans performing an act of
group foraging on a school of fish is not the equivalent of a flock of
dromaeosaurs attacking a tenontosaur.

2) Bird intelligence...
Several species of extant birds are indisputably intelligent (for birds).
Precisely which theropods are their prehistoric equivalent? And why? To
which theropods do we assign this exalted level of intelligence?
Generalizing that theropods were intelligent or that theropods hunted in
"packs" simply because we see these traits in *some* modern birds is simply
illogical. Undoubtedly, some theropods were probably fairly "intelligent"
(for theropods), but it's hard to gauge just how intelligent. Using
*extreme* modern examples is bad science.

3) Slashing claws...
The "killer claw" of _Deinonychus_ is *rounded* on its underside, hardly a
shape conducive to the "razor edge" of the purported "killer claw", since
the keratin would conform to the shape of the bone. In fact, it resembles
nothing so much as a raptor claw, and was just-as-likely used in the same
manner, to hold down prey while the prey was being dispatched. Ken
Carpenter, with whom I had a long discussion about this subject at SVP in
New York in '96, agrees with this assessment.

All the evidence for "pack hunting" in theropods is marginal at best, and
*can* (as Larry Dunn so aptly illustrated) be interpreted in other ways. I
know it's "cool" for theropods to be "pack-hunters", but "cool" isn't what
dictates scientific thought.


Brian (franczak@ntplx.net)
http://www.geocities.com/CapeCanaveral/Launchpad/2045/