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Re: T. rex & predatory behavior (was: Jurassic Park 4: Electric Boogaloo)

 1.) On Monday, February 07, 2005 12:05 AM
 "Jordan Mallon" <jordan.mallon@gmail.com> wrote:

 > You don't have to look as far as the Carcharodontosauridae to see
> packing behaviour in theropods if you consider Barnum Brown's original
> Albertosaurus bonebed in Dry Island, AB as evidence of gregariousness.

 Yes. Thanks. In the discusion of the predatory/scavenging behavior
 in T. rex I first taught of that TV programme because they mentioned
 the animal in it.

 2.) On the
started here on the list.

 Here's something on predatory behavior of T. rex:

 James O. Farlow and Thomas R. Holtz, JR. 2002.
 Paleontological Society Papers, v.8:251-266.

> "Predation vs. scavenging.âPerhaps the best
> known predatory dinosaur, Tyrannosaurus, has
> been suggested to have been an obligate scavenger
> (Horner, 1994; Horner and Lessem, 1993; Horner
> and Dobb, 1997). Horner (1994) argues that several
> morphological features of Tyrannosaurus would
> have precluded a predatory lifestyle: 1) relatively
> small size of the eye that would have prohibited
> spotting prey at a distance; 2) limb proportions
> indicative of slow top running speeds, which would
> have prevented Tyrannosaurus from chasing and
> capturing prey; 3) disproportionately tiny forelimbs
> that would have been useless for holding prey; 4)
> relatively broad teeth that depart from the expected
> blade-like configuration for teeth of a predator.
> We do not find these arguments persuasive. The
> size of the orbit of Tyrannosaurus relative to its skull
> size is in fact rather large for a reptile of its size
> (Fig. 3). Furthermore, the dimensions of the orbit
> suggest that Tyrannosaurus had a big eye in absolute
> terms, which would have increased its lightgathering
> capacity and thus its acuity (Walls, 1942;
> Dusenberry, 1992)."
> [...]
> "...metatarsus/femur or tibia/femur length ratios
> indicate that it was likely as fleet, or faster, than
> other big theropods, and certainly faster than the
> herbivorous dinosaurs that were its likely prey
> (Gatesy, 1991; Holtz, 1995).
> Hornerâs last two arguments strike us as begging
> the question. Without explicitly saying so, he is
> hypothesizing that grasping forelimbs are a necessity
> for killing prey (which will be news to wolves,
> seriemas, and secretary birds), and that animals with
> broad-based teeth are unable to kill prey with them
> (which orcas and crocodiles will find surprising).
> Because the morphology of Tyrannosaurus matches
> the predictions of his hypotheses, Horner concludes
> that Tyrannosaurus could not have been a predator,
> without first testing those hypotheses.
> The brain of Tyrannosaurus had respectably
> large olfactory bulbs (Brochu, 2000), suggesting
> that the sense of smell was quite acute in this
> dinosaur...
> ...a keen
> sense of smell would have been useful for picking
> up the scent of live prey"
> [...]
> "In short,
> we suspect that Tyrannosaurus and other
> carnivorous theropods were, like most extant
> predators, opportunistic carnivores, eagerly
> searching for carrion (in which activity the large
> body sizes of many theropods may have been an
> advantage; Farlow, 1994), but also killing prey
> whenever possible."