Re: T-rex as ankylosaur specialist?

["T. Michael Keesey" <keesey@gmail.com>]

On 5/30/06, Jerzy.Dyczkowski@unibas.ch <Jerzy.Dyczkowski@unibas.ch> wrote:
> Adaptation for walking instead of speed is well supported by that 
> ankylosaurids
> were even slower.

But what in that size range *isn't* slower?

Plus, young/small tyrannosaurids were probably fairly speedy.

> Combination of short arms and strong shoulder bones could be adaptation to
> wrestling with such prey. I suggest, that T-rex first grasped ankylosaurid
> avoiding both tail club and spikes. It then used arms, together with jaws and
> weight to pull ankylosaurid to the side, exposing vulnerable underbelly.

I have trouble seeing those little arms get around something as wide
as an ankylosaurid.

> Suggested sociability of carnosaurs means that armor and tail club of
> ankylosaurids was poorer defense than we think.

(Tyrannosaurids aren't carnosaurs; they're coelurosaurs.)

Also, ankylosaurids are much rarer than hadrosaurids and ceratopsians.
Not that tyrannosaurids *couldn't* have preyed on them, but why pass
up those big herds (flocks?) of unarmored duck-bills to go after a
living tank?
--
Mike Keesey
The Dinosauricon: http://dino.lm.com
Parry & Carney: http://parryandcarney.com