[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Dromeosaurid behavior........Pack hunting! (long)



I like this discussion.

My interest in the dromeosaur kill sites is in what it says about how
advanced dinosaurs were in terms we usually apply to modern predators.
Pack hunting implies fairly advanced neuroanatomy, probably even
methods of signaling. (Maybe the wagging of feathered tails!)

In the end years of the 20th c. we have mental images of dinosaur
behavior based on our modern footage of  lions, hyenas, etc.

In the end years of the 19th c. we might have based our mental images
on observations of lizards.

In the 21st c. we may learn (I think we will) that we should base
our mental images of dinosaurs more on observations of eagles
and secretary birds, modified by considerations of prey mass that
we take from lions, etc. I have been very impressed by the
the work of Irene Pepperberg on bird intelligence in African Grey
parrots and by recent  observations and tests of intelligence in crows.
Social interaction appears to be more important than brain mass
in driving intelligence.

We have to test these theories against the fossil sites with a critical eye,
but not avoid theorizing because the data is incomplete.

I also agree that "fighting over someone else's prey" is an anthropomorphism.
Food is food. Who caught it is immaterial. The questions are: can
it be eaten and who gets to eat it?

Also note:
 If we count ants raising aphids, domestication may have occured in
the Cretaceous.
.............................................................
Thomas R. Holtz, Jr. wrote:

> At 12:16 AM 4/29/99 -0700, Joe Cooley wrote:
>
> >>In a message dated 4/28/99 6:54:20 PM EST, gderkits@lucent.com writes:
> >>
> >><< Presumably the Deinonychus were
> >> killed by the Tenontosaurus during their attack on it. >>
> >>
> >>Why couldn't they have been killed fighting over the carcass? Just
> >curious...
> >
> >Principle of Uniformitarianism.  This means what is happening now happened
> >way back when too.  Since pack hunting goes on now, it seems relatively safe
> >to assume that it occurred back in the Mesozoic as well.
>
> Yikes!!!  No!  Flag called on account of misue of the Principle of
> Uniformitarianism!
>
> (That principle is normally used in conjunction with geologic processes, and
> not biological ones, anyway).
>
> It is NOT safe to assume that all behaviors found in the modern world were
> present in earlier times.  Heck, you could then argue "domestication occurs
> in the Holocene, therefor Late Cretaceous coelurosaurs domesticated Late K
> Asian protot-ungulates".
>
> For complex behaviors, or behaviors currently restricted to a single clade,
> you cannot just assume they were present at any earlier time.  If you are
> proposing unusual (derived or complex) behaviors for some fossil form, you
> should back it up with some sort of testable or supporting evidence
> (morphological structures which correlate with that behavoir; phylogenetic
> bracketing; good old fashioned taphomony (can't be beat!); etc.).
>
> >Also fighting over
> >food is a waste of energy.  Especially when a carcass the size of a
> >Tenotosaur most likely could have fed quite a few Deinonychus.
>
> Ummm..., I suggest you watch footage of carnivores at a kill site.
> Squabbling is quite common, and in some taxa (Komodo dragons, for instance)
> very serious wounds can be inflicted as a result.
>
> Thomas R. Holtz, Jr.
> Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
> Dept. of Geology              Email:tholtz@geol.umd.edu
> University of Maryland        Phone:301-405-4084
> College Park, MD  20742       Fax:  301-314-9661