Re: Laelaps and Brontosauria (was Re: Resending)

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

Jay (sappororaptor@yahoo.com) wrote:

<Why not just abandon Brontosauria? It's original announcement was because of a
purported relationship between therizinosaurs and sauropodomorphs. Clearly, no
one is realistically advocating that anymore. Also, it's based on Brontosaurus,
itself invalid by synonymy. We already have the names Plateosauridae,
Plateosauria, Prosauropoda, Anchisauria - The topologies of all of which could
change following a revision in cladistics. Eg. Anchisauria originally proposed
in 2004 for the Anchisaurus + Melanorosaurus clade assumed a close relationship
between these taxa; now 1 year latter, Anchisauria could include Anchisaurus
and all other sauropodomorphs excluding Saturnalia, Thecodontosaurus,
Plateosauridae, & Massospondylus. See http://dml.cmnh.org/2005Aug/msg00240.html
for this.>

  Why would we want a name like "Brontosauria" for this clade? Possibly because
it's inherently aesthetic and elegant. The name derives from the second, if not
the first, most recognizable fossil name in history (O. C. Marsh's greatest
legacy, perhaps). Thus it's appeal is very strong. Original useage does not
preclude name useage, and exaptation of nomenclature has been done before,
where a name's "old" or "original" meaning (example, Coelurosauria used to
include all the SMALL, gracile theropods, including coelophysids, as well as
traditional coelurosaurs we know and love, but NOT the big animals such as
tyrannosaurids) is reused for the sake of preventing new names from entering
the literature when an old one's meaning need be only slightly modified. When
Carnosauria was redefined to be nearly identical to Allosauridae plus a few
taxa, it retained its usefulness following Novas and Holtz analyses which
served to destroy the traditional content.

  Now, Sauropoda's original content has changed and traditionally excluded such
animals as *Massospondylus* and *Anchisaurus* which, according to Yates'
analyses, are closer to "traditional" sauropods than to *Plateosaurus*, a stem
based relationship that has been defined as the characteristic for Sauropoda.
Are they "sauropods" in the aesthetic, "known" sense? No, probably not.

  Cheers,

Jaime A. Headden

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

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