[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

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!


Jaime A. Headden
The Bite Stuff (site v2)

"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)
Hotmail has tools for the New Busy. Search, chat and e-mail from your inbox.