[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Troodon again



At 06:12 PM 9/22/97 +0100, you wrote:
>Dear everybody,
>
>If you don't mind I would like to continue arguing about the intelligence of 
>dinosaurs.
>I have now the concrete data. The Troodon had 0.1% brain to body mass ratio,
>( the ratio is the important thing not the absolute size )
>and if we do not count it's tail ( since we want to compare to mammals that 
>usually do not have a heavy tail ) than it is 0.13%

But the tail IS part of the body mass (and a fraction of the brain would be
involved in running the tail), so you cannot dismissis it, any more than you
can dismiss the arm or leg of a gorilla.

>The primates have about 1% to 0.15% brain to body mass ratios. The adult male
>gorillas have something like 0.2-0.15%
>And the Homo Sapiens have something like 2%

Ah...,  I see where you might be misled.  Don't forget to scale you
brain/body ratios to the *total body size*.  If you don't, you wind up with
nonsense like kittens of _Felis cattus_ having four or five the brain/body
size as adult _Panthera leo_ (with no apparently stupidity in lions compared
to kittens), or rodents having greater brain/body sizes than humans!

See the work of Hopson or various others on brain/body size and
encephalization quotients (referenced in most dinosaur books, such as
Fastovsky &  Weishampel's The Evolution and Extinction of Dinosaurs).

>So the Troodon ( and probably other coelosaurs if I know it's group name well )
>are not so bad.

That's "coelurosaur".

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661