Re: Emus a Model for Dinosaurs?

[dinoboygraphics@aol.com]

In all fairness, "quite different" is relative.  Neornithes limb 
mechanics are very similar to dinosaurs in their articular contacts 
(even accounting for fusion of the metapodia and the tibiotarsus).  
Limb excursion (as Tim and Jim and Jim noted) is generated somewhat 
differently (shifting from the primitive acetabulum based locomotion to 
the more derived knee-based limb excursion), but the maximum and 
minimum ranges of motion are very similar, including off-axis motion 
(which is important).  And the actual plantar surface of the feet (and 
the internal bones, tendons, and ligaments that create it) of modern 
cursorial dinosaurs are almost identical in how they function to their 
Mesozoic brethren.  Certainly much better than using most extant 
placental feet to understand the biomechanics of Mesozoic mammal 
trackways.

Scott

Scott Hartman
Science Director
Wyoming Dinosaur Center
110 Carter Ranch Rd.
Thermopolis, WY 82443
(800) 455-3466 ext. 230
Cell: (307) 921-8333

www.skeletaldrawing.com

-----Original Message-----
From: jrccea@bellsouth.net
To: andreasj@gmail.com; dinosaur@usc.edu
Sent: Fri, 27 Oct 2006 8:41 AM
Subject: Re: Emus a Model for Dinosaurs?

They are.
JimC

Andreas Johansson wrote:

> Aren't neornithine leg mechanics quite different from those of
> "classical" theropods?


________________________________________________________________________
Check out the new AOL.  Most comprehensive set of free safety and 
security tools, free access to millions of high-quality videos from 
across the web, free AOL Mail and more.