RE: Pack-hunting behavior ( was RE: No K grasslands (was RE: Cretaceous angiosperms) )

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Jean-michel BENOIT
>
> HP Tom Holtz wrote :
> >SNIP<
> 1) The evidence for pack-hunting in dromaeosaurids is, at present,
> restricted to the species _Deinonychus antirrhopus_.
> Extrapolation of this
> behavior to all members of this clade, regardless of size, environment,
> etc.
> is as inappropriate as extrapolating pack hunting to all canids because of
> dholes, wolves, and Cape hunting dogs; to all hyaenids because of the
> spotted hyena; or to all felids becaues of lions.
> <SNIP>
>
> What evidence do we have that _D. antirrhopus_ had a pack-hunting behavior
> and what evidence ( or lack of evidence ) do we have that other
> dromaeosaurids didn't?

Remember that pack-hunting does not have a particular set of
ecomorphological traits: that is, there isn't a body type that is present in
pack hunting that is not found in close relatives which are solitary or pair
hunters.  If you want to test this, try telling a tiger from lioness from
its skeleton.

So the evidence, such as it is, for pack-hunting in dromaeosaurids is
taphonomic associations of multiple individuals of _Deinonychus_ with the
much-larger _Tenontosaurus_, but not with other Cloverly herbivores (e.g.,
_Sauropelta_).  The primary work on this was Maxwell, W. D., and Ostrom, J.
H., 1995, Taphonomy and paleobiological implications of
_Tenontosaurus_-_Deinonychus_ associations, J. Vert. Paleontol. 15:707-712.

Note that this particular topic has been discussed ad nauseum before on the
list, so it might be very useful if people consulted the Dinosaur List
Archives (http://www.cmnh.org/fun/dinosaur-archive/index.html) to review the
material presented there.

Back to work...

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796