RE: REPTILES

["Stewart, Dwight" <Dwight.Stewart@VLSI.com>]

> -----Original Message-----
> From: Tetanurae@aol.com [SMTP:Tetanurae@aol.com]
> Sent: Wednesday, December 16, 1998 6:58 PM
> To:   Dwight.Stewart@VLSI.com; th81@umail.umd.edu; padron@online.no
> Cc:   dinosaur@usc.edu
> Subject:      REPTILES
> 
> Dwight Stewert wrote:
> <<....with reptiles and amphibians ranked only above insects, IF that.
> The
> facts simply don't bare that out; it's a kind of prejudice (IMHO!).
> Reptiles
> are better suited for certain niches.  The shear endurance of reptiles
> throughout vertebrate history amply proves that.>>
> 
> Indeed our mammal-ocentric views bely the fact that the 2nd or 3rd class
> animals in fact out number mammals in diversity and biomass increadibly.
> 
> <<Correct me if I'm wrong (really asking for it here!), but aren't both
> birds
> and mammals evolved from reptiles?>>
> 
> Well...  it all depends on what you think is a reptile....  If you mean,
> as
> according to the old-fashioned definition, diagnosed as any tetrapod that
> doesn't have fir or feathers, yet does lay eggs on land, then yes, both
> mammals and birds evolved from reptiles.
> 
> In point of fact however, according to rigourous phylogenetic definitions,
> Reptilia is now defined to exclude mammals and their ancestors, and to
> INclude
> birds and their ancestors (dinosaurs).
> 
> Peter Buchholz
> Tetanurae@aol.com
        [Stewart, Dwight]  
        #####################################

           I see what you mean.  But, at some more distant point, mammals &
reptiles would share a common ancestor.
        Which brings up a point about so-called "mammal-like" reptiles like
Dimetrodon.  Is that term still applicable?
        If so, were these animals an "evolutionary dead-end"?  I frankly
wonder if non-avian dinosaurs had not become
        extinct, if we would even be here to discuss this?  :-)

        Dwight