[Taxacom] Reptilia

Kenneth Kinman kennethkinman at webtv.net
Sun Mar 15 16:09:08 CDT 2009


Dear All,
     As David noted, Reptilia is "real".  I have often wondered if such
taxa would become more acceptable if we stopped calling them
"paraphyletic" and instead called them truncated clades.  I see no
problem in separating off Class Aves, as long as I put an {{Aves}}
marker in Class Reptilia next to its sister group (and the same with
Class Mammalia).     
      The study of tetrapod vertebrates has long been separated into
three (Herpetology, Ornithology, and Mammalogy).  The latter two study
clades (Aves and Mammalia), while Herpetology studies a truncated clade
(Tetrapods minus birds and mammals).  Is there any good reason not to
continue doing so?  Likewise, the study of Ichthyology also studies a
truncated clade (Vertebrates minus tetrapods).  Seems like a pretty
useful concept to me, whether you call them paraphyletic taxa or
truncated clades.  
         --------Ken Kinman                                   
P.S.  Why is the phrase "Birds are dinosaurs" any more correct or useful
than "Birds are dinosaur descendants".   The latter actually seems more
precise and preferable (except to those who forbid a truncated clade
like the traditional Dinosauria).

-------------------------------------------------------------      
David Campbell wrote: 
"Real" is of course a problematic term. Reptilia is a paraphyletic group
of organisms with certain similarities that provide or exclude certain
ecological options, so in one sense it is "real"; however, almost all
phylogenetic analyses do not support it as monophyletic, and those that
have can readily be explained as being misled by plesiomorphic or
convergent features. 





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