Re: STRANGE THEROPOD SKULLS

["Jaime Headden" <jaemei@hotmail.com>]

<Regarding the bizarre skull of the Antarctic theropod 
_Cryolophosaurus_, Tom Holtz writes..>

<<The skull of Cryolophosaurus is pretty puzzling as currently 
described, particularly the squamosal-postorbital-jugal contact (which, 
in all right-thinking theropods, do NOT form a single contact in the 
middle of the infratemporal fenestra!!).>>

<Tom, what on Earth is a 'right-thinking theropod'? I am still utterly 
confused by the cryolophosaur skull, and with such a poor, preliminary 
description to go on (Hammer and Hickerson 1994), we are all in the 
dark. Someone should get hold of the thing and describe it properly - it 
looks (from photos, not the god-awful diagrams provided by Hammer and 
Hickerson) very significant.>

*Cryolophosaurus* is so early in the fossil record, possibly the first 
true carnosaur (Eucarnosauria? with Carnosauria including that group and 
all other basal tetanurines {megalosaurs, torvosaurs, abelisaurs, and 
*Eustreptospondylus*} excluding Coelurosauria and spinosaurs and 
*Bagaraatan*---however he fits in, and I've yet to see a skeleton or 
single bone of this creature)

<I still find it hard to believe that the jugal does project so far 
dorsally as to suture with the squamosal and therefore divide the 
laterotemporal fenestra into two - this is utterly unique if true. 
Mind you, tyrannosaurs come pretty close but with a totally different 
morphology (both the squamosal and quadratojugal rostrally invade the 
lat. fen.), and Hu's diagram of _Dilophosaurus sinensis_ does too: 
here, what appears to be the squamosal divides the lat. fen. and 
apparently reaches the dorsal bar of the jugal. Does anyone have any 
photos of the skull to see if this is for real?>

Try the Royal Tyrrell Museum at

http://tyrrell.magtech.ab.ca/lostf/dilopho.html.

<<I think that Bakker et al.'s and Sereno's suggestion that 
Eustreptospondylus is closely related to Torvosaurus may have some merit 
based on current data. Unfortunately, both are less complete than one 
(okay, I) would like... :-(>>

How about this: *Baryonyx's* pelvis shows remarkable similarity to the 
referred pelvis of *Megalosaurus* (OUM, no number given) as seen in _The 
Dinosauria_ and _Dinosaurs: the Encyclopedia_. And don't get me started 
about *Afrovenator* and *Eustreptospoindylus*---though Afro and 
sinraptorids is also very interesting.... Hmm. Would *Piatnitzkysaurus* 
and *Monolophosaurus* and *Yangchuanosaurus* sound interesting as a 
group: look at their pelves (especially the ischia).

<There are many, many problems with all of the characters that both 
teams used to support a _Eustreptospondylus_-_Torvosaurus_ link (you 
want me to go through them?)>

Yes, if you would. At least for my benefit. I've worked this problem and 
found them contiguous as based on their ilia alone (and exclusive of 
nearly all other basal tetanurines/ceratosaurs). I've posted similar 
threads, you may recall.

<... nevertheless, there are still a few similarities that look very 
significant (e.g. loss of quadratojugal foramen/fossa, tall quadratic 
shafts). I am _hoping_ to do a thorough description of this dinosaur 
sometime in the future: god knows someone has to.>

You may reason with me, but I've got carnosaurs on the brain.

Jaime A. Headden

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