Re: Tyrannosaurus rex was a fast runner

[kyle robert brudvik <krbrudvi@midway.uchicago.edu>]

On Thu, 7 Mar 2002 Buckaroobwana@aol.com wrote:

> Even crocodilians are 
> capable of bursts of speed when ambushing prey at the waterline. Also, 
> doesn't the fact that bears can gallop quickly totally invalidate Horner's 
> femur/tibia argument? What exactly are the leg proportions of bears? As I 
> understand it, they have very short lower legs, but I'm not 100%certain as to 
> exact measurements. In spite of this, bears can move quickly when they need 
> to. If anyone can name a terrestrial carnivore that is always restricted to 
> slow movement, please let me know. It seems to me that Hutchinsons' work on 
> musculature indicates slow speed, while studies of the leg bones indicate the 
> opposite. 

Be careful here, you are comparing obligate quadrupeds with obligate
bipeds.  Especially in your bear example, the spinal column plays a large
role in energy storage and transfer to the legs during running that it
would not play in bipedally dinosaurs.

Kyle Brudvik