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Re: Sapeornis and other Mesozoic Birds

On 9/13/06, Dino Guy Ralph <dinoguy@sbcglobal.net> wrote:
Thanks for the info, Mike!  Of course, even this correction is not
technically ideal in that it's not considered altogether legitimate to use
the term in question as a critical piece of the definition.  On the other
hand, the general public understands the concept "extant birds" (once you
explain to them what "extant" means), so perhaps we can overlook the issue
this time.  Would it be fair to say that cladistic definitions have less
stringent standards as compared to dictionary definitions when it comes to

Depends. If following the PhyloCode (a code for naming phylogenetic taxa which is currently in development; the current draft is at http://phylocode.org), then there are more stringent standards. Anchoring something on "extant birds" is not allowed. All specifiers must be specimens or species (or characters, in the case of apomorphy-based definitions).

I only know of two definitions of Aves which satisfy PhyloCode rules:

- Gauthier and de Queiroz, 2001: "The crown clade stemming from the
most recent common ancestor of Ratitae (Struthio camelus Linnaeus
1758), Tinamidae (Tetrao [Tinamus] major Gmelin 1789), and Neognathae
(Vultur gryphus Linnaeus 1758)."

- Sereno 2005: "The least inclusive clade containing Archaeopteryx
lithographica Meyer 1861 and Passer domesticus (Linnaeus 1758)."

There has been some discussion recently on the ISPN's forum:
(The ISPN is the organization associated with the PhyloCode: the
International Society for Phylogenetic Nomenclature.)
T. Michael Keesey
The Dinosauricon: http://dino.lm.com
Parry & Carney: http://parryandcarney.com