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Cryolophosaurus & the "Lufeng theropod"



First of all, I hope everyone requesting that I
forward the _Psittacosaurus_ integument photos from HP
Michael Schmidt have recieved them. If not, please
e-mail me back.  
     Now, I'll get down to businesss. I believe that
_Cryolophosaurus_, "_Dilophosaurus_" sinensis (which I
will simply call the "Lufeng Theropod") AND
_Dilophosaurus_ may form a clade. I base this
assumption on several rather unique features of the
skull which I will elaborate on. First, though, let me
present my little phylogeny;

____________________Lufeng theropod
\
 \
  \_________________Dilophosaurus
   \
    \
     \______________Cryolophosaurus

I'm not quite sure where this group may be situated, 
but my best guess is somewhere in the basal tetanurae,
as Rauhut (2000) apparently believes. The Lufeng
theropod has a somewhat generalized skull design,
suggesting it is closer to more advanced animals, like
_Monolophosaurus_. _Cryolophosaurus_ and the Lufeng
theropod share: 1) A convex dorsal margin of the
antorbital fenestra. 2) A hypertrophied base of the
preorbital bar. 3) A reduced, dorsally-placed anterior
flange of the lacrimal. 4) Oval obturator foramen in
pubis.  _Cryolophosaurus_ and _Dilophosaurus_ share 1)
An elongate wing-shaped jugal process of the
postorbital. 2) Anteriorly-shifted quadratojugal
process of the squamosal. 3) Enhanced striation of the
nasolacrimal crest. *4) Posterior (or lateral) "spur"
on lacrimal.
     The morphology of the lateral temporal fenestra
of _Dilophosaurus_ almost looks like a transitional
phase between the typical theropod condition and the
distinctive division of the fenestra in
_Cryolophosaurus_. C. ellioti apparently shifted its
crests posteromedially, forming the fan-shaped
arrangement. While some reconstructions of
_Dilophosaurus_ show a straight dorsal margin of the
AOFE, viewing the type material suggests an albeit
reduced but still present dorsal bowing, and a
slightly thicker base of the preorbital bar. It looks
as though D. wetherilli simply lowered it's antorbital
fossa. As Hammer & Hickerson (1994) state, the
postcrania of C. ellioti is quite primitive, and
ceratosaurian. So, in conclusion to this very brief
report, I would like to say that all 3 animals have
many differences, but share key anatomical features
which suggest, at least to me, that a superfamily
should be erected for this clade. Dilophosauroidea,
anyone?


Cheers,
 
Waylon Rowley



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