Group hunting (was Killer whales and theropods/ Longest Animal)

["Ralph Miller III" <gbabcock@best.com>]

Berislav Krzic <veselinka.stanisavac@siol.net> writes:
> I wonder if there is any material proof that hints the
> ability of complex group hunting techniques in predatory dinosaurs - the
> feature that many dinosaur artists paint and draw extensively.

As Karen Chin relates on pages 373-374 of _The Complete Dinosaur_, Maxwell
and Ostrom have described 15 different Lower Cretaceous sites in Montana
with _Deinonychus_ teeth and _Tenontosaurus_ bones together, but few if any
sites associating _Deinonychus_ teeth with the remains of other prey
genera.  The implication is that _Deinonychus_ fed preferentially on the
much, much larger _Tenontosaurus_, an animal which would presumably be too
large for only one of these dromaeosaurs to subdue on its own, and so,
assuming the dromaeosaurs weren't merely scavenging at all of these sites,
these assemblages suggest group hunting on the part of _Deinonychus_.  The
most famous evidence is the Yale _Deinonychus_ quarry (YPM 64-75) which
includes skeletal elements from four _Deinonychus_ specimens in association
with the remains of a _Tenontosaurus_ individual, in a deposit that does
not suggest any water transport.  _The Complete Dinosaur_ shows a full-page
diagram of the site on page 375, and gives the following reference:

Maxwell, W.D., and J.H. Ostrom. 1995. Taphonomic and paleobiological
implications of _Tenontosaurus_--_Deinonychus_ associations.  _Journal of
Vertebrate Paleontology_ 15: 707-712.

I also recall mention of a trackway suggesting that a group of sauropods
was pursued by a group of large theropods (possibly something like
_Allosaurus_), but I have no ref., so we'll have to see if someone else can
come up with more information... 

-- Ralph Miller III     gbabcock@best.com