RE: Eustreptospondylus & Carcharodontosaurines

[Waylon Rowley <whte_rbt_obj@yahoo.com>]

--- "Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>
wrote:
> My SVP analysis this year, which includes data from
> this specimen, does
> place _Ceratosaurus_ and the abelisauroids
> (Ceratosauria proper) as more
> closely related to tetanurines than to
> coelophysoids.  This idea had been
> previously proposed by, among others, Bakker and
> Paul, and is popping up in
> a number of new analyses.

HAH! I knew it. Can't wait to see the studies. While
I'm still sticking with the
Carcharodontosaurines-as-Allosauroids idea, I'm still
a bit wishy-washy. There's an awful lot of convergence
going on....almost too much. Carchs are just too
primitive to be advanced Allosauroids. 
 
> There was no particular affinity found between
> _Cerato._ and _Eustrept._, but I did think it was 
> interesting how similar those
> two specimens (both juveniles) did appear.

Maybe they just retain primitive features through
adolescence. 

> It is still awaiting description.  The main form I
> would like to compare it to is the large allosaurid
> material that Dan Chure named _Saurophaganax_.
 
I wasn't aware pectoral elements had been recovered
for ?A. maximus. 
 
> Incidentally, your idea about the fluting of
> carcharodontosaurine teeth is interesting, and 
> perhaps pursuable via some sort of
> stress analysis.

Similar to the T. rex tooth and cow pelvis study, eh?
Sounds like a good idea, especially with the
tremendous number of _Carcharodontosaurus_ teeth being
sold all over. Now you just need something similar to
Titanosaur scutes...hmmmmmmm.    


> However, it isn't necessarily that _Giganotosaurus_
> had particularly narrow teeth: they seem to plot 
> allometrically along with other standard ziphodont
> (bladelike teeth) with symmetrical carinae, at least
> in my limited data. We'll have to see if HP Josh 
> Smith looked into that particular aspect of tooth 
> morphology.

I suspect that there would be a strong evolutionary
trend toward reducing recurvature and angling the
denticles distally because of frequent chips and wear
at the tips. Hell, an _Allosaurus_ tooth would snap in
half if it was rammed into a large dermal ossicle.
Makes me wonder why Abelisauroids hung onto the
plesiomorphic condition. Last I heard they have
identified lambeosaurines and other hadrosaur material
from the LK of Gondwana. Maybe Abelisauroids took
advantage of the new prey source and left the
sauropods alone. Someone should look for indications
of diet in Abelisaur bones. 

Cheers,
Waylon Rowley
 


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