Re: Dinosaur success tied to atmospheric oxygen levels?

[jbois@verizon.net]

Quote from article at:
http://www.sciencedaily.com/releases/2006/10/061023193630.htm


>"Dinosaurs thrived and nothing else did. There's an explanation for that, and 
>it is that the air sac breathing system in dinosaurs and their descendants, 
>modern birds, is more efficient than systems used by other organisms," Ward 
>said.
>He and his colleagues tested that hypothesis by examining the breathing system 
>used by birds. They found that at sea level birds breathe 30 percent more 
>efficiently than mammals and at 5,000 feet in elevation birds are 200 percent 
>more efficient.

If oxygen utilization-efficiency is the sine qua non of niche dominance (as the 
article claims), why then do mammals dominate the large animal niche?





From: Guy Leahy <xrciseguy@sbcglobal.net>
Date: 2006/10/24 Tue PM 02:36:17 CDT
To: dinosaur@usc.edu
Subject: Dinosaur success tied to atmospheric oxygen levels?