Re: Taxon Search

["Jaime A. Headden" <qilongia@yahoo.com>]

Mickey Mortimer (mickey_mortimer111@msn.com) wrote:

<Except that he uses uncertain content as a reason to make some clades
inactive, like Galton and Upchurch's (2004) Anchisauria.  So it's a
double-standard.>

  How clear _is_ "Anchisaurus, Ammosaurus, Riojasaurus, Melanorosaurus,
Camelotia, and Lessemsaurus" ? Or any clade that uses "Neornithes" as a
specifier, or refers to "all dinosaurs closer to [name] than to [name]" type
formulations? Sereno (2005) details how these are ambiguous, uncertain, or
should be formulated clearly, basing these on specific wordings to erase
ambiguity. This is likely why it's inactive. 

<I have it.  I haven't read it yet, but I doubt I'll agree with some parts
(like not using eponymous specifiers, which Sereno still refuses to do a lot).>

  Which is precisely why these taxa are ambiguous. "Neornithes"-type
definitions require continuing referencing to other definitions, and thus are
not self-contained definitions. Unlike the practice of mammalogists today,
even, definitions should NOT be dependant on the phylogram of reference, but to
any phylogram you would find yourself facing, while the formulation with "all
neornitheans" or "all dinosaurs" in whatever arrangement are referenced to that
study alone. This is yet more cause of ambiguity.

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


                
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