Re: birds are reptiles?!

[Tom Holtz <tholtz@geochange.er.usgs.gov>]

>So what exactly is a reptile?  Phylogentically, either nothing, or all
>amniotes.  So reptile = amniote.  Of the two words, the latter is far
>more precise in definition and usage.  So can we please forget the former,
>or at least remember it as an old but inaccurate (phylogenetically speaking)
>description of some amniotic tetrapods, and not use it in day to day
>parlance amongst people who understand perfectly well what an amniote is?

In Gauthier's terms:

Reptilia = the most recent common ancestor of turtles, lepidosaurs, and
archosaurs, and all of that ancestor's descendants.

If mammals are closer to diapsids (lepidosaurs and archosaurs), than
Amniota = Reptilia.

If mammals are outside of a diapsid-turtle clade, than Amniota contains
Reptilia.

                                
                 Thomas R. Holtz, Jr.                  Phone: 703-648-5280      
                 Vertebrate Paleontologist         Fax:    703-648-5420
tholtz@geochange.er.usgs.gov ------------>       th81@umail.umd.edu
U.S. Geological Survey          ------------->       University of Maryland
Branch of Paleontology & Stratigraphy ---->       Department of Geology
MS 970 National Center
Reston, VA  22092               ------------->        College Park, MD  20742
                                                          U.S.A.