Re: thoughts on which nodes to name

["Mickey_Mortimer11" <Mickey_Mortimer11@email.msn.com>]

Patrick Mellor wrote-

>      Is there any rigorous and non arbitrary reason to retain terms like
> 'reptilia' and continue to try to squeeze old Linnean concepts into
> phylogenies, e.g. 'reptilia' is now basically defined as any non-synapsid
> amniote, this does not fit with the vernacular definition of the word
> reptile, and is misleading, to say the least, to non-specialists. Why not
> just scrap it as a term? Why, apart from an attempt to keep to tradition,
is
> the node including all non synapsid amniotes except mesosaurs so
important,
> and is there any non arbitrary way to decide which nodes to name without
the
> lunacy of naming every node on every cladogram with slight variations of
> group names? Sorry for the slight rant :) Am writing an essay 'What is a
> Reptile' for a tutor and it is giving me a slight headache.

Short answer for this well beaten topic.....
The reason Reptilia is retained is because it has historical priority (being
named in the archaic days of yore) and phylogenetic definitional priority
(being defined as all descendants of testudines, squamates, Sphenodon and
crocodilians, and their common ancestor; Gauthier et al. 1988).  The
vernacular definition of reptile includes those taxa listed in the
definition, the definition just assures it is monophyletic.  So it's not
defined the way it is to be a group of organisms containing every
non-synapsid except mesosaurs.  Everything in Reptilia has always been
viewed as a reptile for at least the last century, besides avians.
Including birds in the Reptilia is surely less confusing than scrapping the
term and using some new term for the group (words do change in definition
over time), when reptile is so intrenched in both the public and scientific
communities.  If centipedes were suddenly found to be deeply nested in the
Mammalia, would you suggest renaming Mammalia?  I think not.  There's no
objective way to decide which clades to name, but I recommend at least
waiting for a majority consensus that the topology is real.

Micket Mortimer