Message 2003-02-0003: Re: New Dinosauricon Taxon Pages: _Therizinosauria_

Fri, 31 Jan 2003 22:30:32 -0800 (PST)

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Date: Fri, 31 Jan 2003 22:30:32 -0800 (PST)
From: "Jaime A. Headden" <>
Subject: Re: New Dinosauricon Taxon Pages: _Therizinosauria_

Mike Keesey ( wrote:

<Except that this species was originally named as _Tyrannosaurus bataar_!
So, you see, it would have to remain _Tyrannosaurus bataar_, even though
it would be closer to (synonymous with?) _Tarbosaurus efremovi_ than to
_Tyrannosaurus rex_.>

   You needn't use exclamation points. Synonymy between *Tarbosaurus
efremovi* (named second) and *Tyrannosaurus bataar* (named first) were
established as long ago as 1960 by Rozhdestvensky. This has since been
followed by most theropod workers, as detailed in earlier posts, though
George has advocated that each of these species is distinct from one
another, to the point of removing certain species from certain "generic"
identities. Here, the oldest non-overlapping nomina which establish a
unique identity from another type species are used to indicate the species
binomen. Since PIN 557/1 is not the same as AMNH 5881, and show several
distinct apomorphies from it, as well as the types of other specimens, the
oldest names that separate it from *Tyrannosaurus rex* are *Tarbosaurus*
and *bataar*; *efremovi* is a junior variant of *bataar* and this the rule
applies to pterosaurs. *Ornithocheirus* is best established upon only its
type, and if of dubious validity, becomes nearly useless to pterosaurian
taxonomy. As a species that has autapomorphies from the diagnostic types
of other pterosaur species, the provided name that separates *latidens*
from *cluniculus*, *benzeli*, *sedgwicki*, and *mesembrinus* (for
instance) is *Istiodactylus*. It becomes the valid, distinguishing prima
nomen which does not occur in any other taxon of animal available to the
authors. So *Nanotyrannus lancensis* would be upheld if not a junior
variant of *Tyrannosaurus rex*; if a sister taxon, it is still
*Nanotyrannus*. There is one reason, then, why I support use of
*Megapnosaurus* (as validly named, if not in all ethics [?] supportable
for aesthetic reasons) for *rhodesiensis* versus *bauri*; similarly,
*baldwini* and *kayentakatae* are different and cannot be referred to any
of the other species, su should be distinguished as such. To preserve
historic usage, both nomina are used for both informative and aesthetic
purposes. As in any clade, the species name is capitalized, and thus
*mongoliensis* (all of them that are dinosaurs and more) needs to be
substantiated further, and *Velociraptor mongoliensis* versus *Adasaurus
mongoliensis* makes better sense and is less upsetting to the literature
and still provides the same essential framework.

<But renaming it to _Istiodactylus latidens_ would have been invalid in
the first place, since it was already named _Ornithocheirus latidens_..>

   As I wrote in the original post, each species has a unique prima nomen,
and I just detailed this. I kinda hope it wasn't overlooked originally.

<Lost me ... altered to what?>

   And this may be the source of the confusion. The prima nomen is changed
to show it is not synonymous with *Ornithomimus velox*; since
*Ornithomimus* already exists for what is currently considered a valid
species (as of any recent publication _not_ contradicting its validity)
the species secunda nomen *minutus* originally included with *velox* must
be removed. If it not synonymous with another species, a prima nomen that
is unique from all others must be coined. The phrase "species minutus ex
Ornithomimus, non O. velox" can be used to show its current relationships,
or "*Ornithomimus x minutus*" (because the next suggestion might have too
much baggage given multiple fossil species) or the good ol'
"*'Ornithomimus' minutus*" ... the prima nomen is not wrong, so I disfavor
quoting it, or adding "cf." in from of these names.

<I agree that the system would work in theory, but I think people are too
used to the prima nomen indicating its relationship. e.g., people would
expect _Megalosaurus bucklandi_ (a basal tetanuran),  _Megalosaurus
saharicus_ (the original name of _Carcharodontosaurus saharicus_, an
allosauroid carnosaur) and _Megalosaurus wetherilli_ (the original name of
_Dilophosaurus wetherilli_, a basal avepod) to be closely related.>

   As demonstrated above, this is not an issue. Neither the primae nor
secundae nomina demonstrate relationship. This may be established upon use
of structure in the names when coined, if not already (*Ornithomimoides*
is not related to *Ornithomimus*, but its name does not actually say that
it has to be).

<Of course, you could create the binomials based on prevalent usage
instead of original usage, but this is subjective and could lead to
arguments. Which is more prevalent, _Paranthropus boisei_ or
_Australopithecus boisei_? Furthermore, this would not account for such
"mistakes" as _Megalosaurus saharicus_ and _Megalosaurus wetherilli_ being
made in the future.>

   At the time, they were valid on their face. The analysis of theropod
postcranmial more cranial material, and a better understanding of theropod
relationship permitted von Stromer first, then Welles, to replace the
original appelation with unique primae nomina. This may be, if adopted,
necessary for all the multiple secundae nomina held under a single prima
nomen; note that I also only advocate this for fossils, where the relative
material does not support the level of referral possible given the
full-anatomy studies present in extant animals. But it is the place, as in
the original structure of the "genus" to name clades to include species
relative to others ... this has always been the case. We may require more
names to include species in conventional "subgenera," "genera," and
"supergenera" roles, which were always subjective lines in the sand
regarding convention of the names they were used to include. Brochu
managed, in 1999, to name a subgroup of *Crocidylus* species with a name
not conventionally used, as it is not a subgenus in the sense used by
others. Clade names need no follow Linnaean structure, but can approximate
them, and this may be more satisfying to the majority, as it only requires
lack of using labels for names, and identifying a pair of names, one
capitalized and one not, to indicate a species. This is less horrifying to
Benton, I'm sure, than the alternative supported by Cantino et al., and in
the Draft Phylocode.

   And why I wasn't posting there, I don't know ... this is being sent to
the PhyloCode list as well, and I will forward my original email as well.
I preserve nearly all, if not all, of the text which Mike Keesey replied
to me with.


>  Better, I think, to abandon the concept of binomials, and let species
>  stand on
>  their own. If the citation is part of the full name, they will be unique
>  and
>  permanent (e.g. _rex_ Osborn 1905). After being mentioned with the
>  citation,
>  they may later be abbreviated by listing just the main part of the name
>  (e.g.
>  _rex_), or listed with a containing clade (e.g. _Tyrannosaurus_ _rex_).
>  This seems the best idea to me, for now, anyway.
>  =====
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Jaime A. Headden

   Little steps are often the hardest to take. 
We are too used to making leaps in the face of 
adversity, that a simple skip is so hard to do. 
We should all learn to walk soft, walk small, 
see the world around us rather than zoom by it.

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

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