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RE: Zootaxa iguanodont paper
Greg Paul wrote:
<The Zootaxa paper does not make it at all clear in anatomical or stratigraphic
terms why R8131 and the associated skeletal elements including the super
massive arm should be referred to Hypselospinus fittoni. R8131 et al were found
in a shoreline quarry below the high tideline, and may be older than the quarry
that produced the type H. fittoni. One thing I have trying to emphasize is that
when it comes to taxonomy pay attention to the bloody stratigraphy because
species do not last long. It is now known that the species of centrosaurs,
chasmosaurs, corythosaurs, lambeosaurines were limited to distinct levels of
the Dinosaur Park formation. Before referring specimens to a known species it
must be first demonstrated they are from the same level of a formation as the
type. Norman keeps referring to specimens being in the Valanginian, but the
stage lasted 6 or 7 million years, what is needed is whether the specimens are
from the lower, middle or upper Valanginian. Nor does the Zootaxa paper cite
Naish & Martill 2008, who showed that the Old Roar Quarry animal is not part of
B. dawsoni.>
Minor, if not major, quibble here, and only to do with this paragraph, rather
than the whole post (or the poster).
Stratigraphy informs on geological deposition, it is not a proxy for
taxonomy. Several workers have gotten into the habit of using it as a proxy or
as a valid chaarcterization method when naming or diagnosing taxa, especially
the nondinosaurian kind. They have used this "method" to split taxa regardless
of morphology, or to make what may seem minor features more significant by
their distance in geologic time. This has included short-event creation of
geologic members of the formation, such as a mudslide, or as a transgressive
event from an intercontinental sea, rather than relying solely on the
morphology of the material. To back themselves up, this proxy has been
supported almost entirely by the authors' own acceptance of the taxonomy of
material within each perceived level, creating the illusion of consistency.
Moreover, it compounds the problems when these authors differentiate taxonomy
on different bases, such as recognizing "genus" as a valid taxonomic criterion,
or "species" which differ from one another solely through their geology; they
can then lump or split as needed to recognize some reality to their geologic
system, and then use that system to inform their taxonomy.
A vicious cycle, and an unscientific one, being used to determine whether a
specimen _can_ be diagnostic!
Cheers,
Jaime A. Headden
The Bite Stuff (site v2)
http://qilong.wordpress.com/
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
"Ever since man first left his cave and met a stranger with a different
language and a new way of looking at things, the human race has had a dream: to
kill him, so we don't have to learn his language or his new way of looking at
things." --- Zapp Brannigan (Beast With a Billion Backs)
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