Re: Ornitholestes

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

Stephen Pickering (StephanPickering@cs.com) wrote:

<In my in-progress Mutanda Dinosaurologica -- a revision and updating of Sam 
Welles's unpublished
manuscript (with 400+ photographs) on Jurasssic theropods -- Proceratosaurus, 
known only by a
skull, is positioned as Maniraptoriformes incertae sedis. The skull, described 
in minute detail
and compared with other taxa, is demonstrably not a ceratosaur. Neither is 
Ornitholestes AMNH 619,
certain aspects of its osteology similar to Proceratosaurus.  The "horn" of 
both taxa is
conjectural, but, as Sam often told me, Gregory Paul's superb restoration is 
probably a conjecture
better than most because the care Mr Paul takes with all of his restorations 
and reconstructions.>

  Yes, it _is_ very fine.  Respect for Greg's skill is very well deserved.  
However, work
progresses on the material of both taxa as the types have been more completely 
prepared now than
they were in the pre-1910's of their original descriptions.  *Proceratosaurus* 
is much thinner in
the skull and indicates some unique features that affiliate it closer to some 
other tetanurans
than is *Ornitholestes*; on the other hand, *Ornitholestes* has some 
superficially maniraptoran
features in the jaws... go figure.

<There is, of course, no excuse for the  horrendously inaccurate restoration of 
Ceratosaurus>

  Assuming that's what it was ... saw the horn and it didn't look as conical as 
all pointed it out
as, but freaky nonetheless; this animal didn't look so much as another dinosaur 
as the other's
resembled their namesakes, indicating to me that if they wanted to do 
*Ceratosaurus,* they would
have been able to make it look so.  Okay, liberties aside, they were not 
stupid.  I doubt it was
_supposed to be_ *Ceratosaurus*, in my opinion.

<Dilophosaurus's two species, moreover, may be sexually dimorphic 
representatives, crested females
to attract males (in this case, males being the crestless forms known as 
Liliensternus) --
speculation, to be sure,>

  Yes.  Very.  Especially since *Liliensternus* shares absolutely none of the 
putative
similarities to indicate it was dimorphic with *Dilophosaurus* in the way the 
two coelophysid taxa
have been posited as being dimorphic (*Syntarsus rhodesiensis* and *Coelophysis 
bauri*). 
Diagnostically, the postcrania of the two are highly divergent and they occupy 
two different
positions in the tree in every analysis I've run, the American form closer to 
the Neoceratosauria
than the German form is.  These also follow vertebral (no dimoprhic 
transformation) and pelvic and
pectoral (some to little? dimorphic transformation, respectively) comparison.

<but more viable than the heterosexist filters one encounters (e.g., the 
gaudily frilled
ceratopsians are often described as "male" to entice females; this is nonsense: 
ceratopsians were
female-dominated).

[snip]

The point is: theropods were logically matrilineal, and "horns", "crests", etc. 
visual signals for
smaller, drab males.>

  I fail to see the evidence for this.  We most certainly lack the specimen 
base to account for
population variables between the sexes except for _possibly_ one or two 
ceratopsid species, much
less theropods or other dinosaurs.  Gender is not a simple issue of "flashy and 
small" to "drab
and big" or whatever comparison you would choose to make, and assign gender 
thusly.  It was once
posited that crestless oviraptorids were females, so some suggested sinking 
*Ingenia* into
*Oiraptor*, supported not at all by any other analysis of anatomy, and by such 
an analysis, found
to be -- pardon the language -- bull.  So far, except for some fairly 
reasonable work from Ostrom,
Witmer, and Sampson, no gender can be assigned to specimens with any 
exactitude.  This is
especially true of work from Larson on *Tyrannosaurus* (used since in 
application to other
theropods), which shall receive some published attention in the near future.

=====
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.

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