Re: Reptilia

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

At 02:35 PM 12/6/98 EST, Philidor11@aol.com wrote:
>So, definitions of reptilia are based on:
>1. 4 limbs/scales/not lactating
>2. the windows (fenestra) system I was quoting from Fastovsky & Weishampel
>1996
>
>I'd appreciate it if anyone with a different definition could add it.  The
>mutability in this field is very interesting to me.
>
Ugh.  (Yes, Jim, you seem to be right... [he said, cryptically]).

First of all, #2 is NOT the definition that Fastovsky and Weishampel use.
As they say, "Reptilia refers to Anapsida and Diapsida, and to all the forms
down to their most recent common ancestor" (p. 86).

There is a BIG difference between a definition of a taxon, and the diagnosis
of a taxon.  Please refer to any of several sources on the subject (I could
recommend pp. 103-105 of Chapter 8 of Farlow & Brett-Surman's The Complete
Dinosaur, for one; or the U Cal Berkeley Museum of Paleontology website
(http://www.ucmp1.berkeley.edu/, I think).

I strongly urge anyone interested in questions as to whether dinosaurs were
reptiles or not to read some of these pieces.  It doesn't hurt to find out
how taxonomy is done.  (Here's a hint: it isn't done by polling over
email... ;-).

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