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In a message dated 97-08-31 18:12:03 EDT, firstname.lastname@example.org (Jonathan R.
> >The obturator notch in the pubis of _M. bicentesimus_ is rather more open
> >(and _Allosaurus_-like) than in known sinraptorids.
> This could have something to do with ontogeny...
Is there good evidence that the animal that the _Sinraptor_ skeleton belonged
to was consederably younger when it died than _Marshosaurus_ or _Allosaurus_?
> >The ischium compares very favorably to _Allosaurus_, having a triangular
> >and a prominent, proximally-placed obturator flange. As in _Allosaurus_,
> >ischiadic rod is long, straight, slender, and flared distally. In this
> >respect it is rather more like the ischium of _Allosaurus_ than like
> >sinraptorids, which are broader and bear a hook at the end.
> Of course, the pelves of the sinraptorids are highly variable,
> having both primitive- and allosaur-like morphologies in the same clade.
Let's get our terms straight. What exactly do you inlcude in Sinraptoridae?
Also, see below.
> >Theropod pelves are far more diagnostic than most people give them credit
> While I have been a big proponent of this in the past, every time
> compare pelvic morphology to phylogeny, I come up short.
Odd that I don't.
> at the case of _Yangchuanosaurus_ and _Sinraptor_. With only the pelves,
> what would you say about them?
I would say that the pelvis of _Yangchuanosaurus_ has been very poorly
reconstructed in the past. In all the drawings I've seen, the ilium is
missing the laterally-directed wing at the front of the preacetabular
process. Also, since at the time of _Yangchuanosaurus_'s description, no
other carnosaurs were known with a hook bounding the pubic foramen, so the
foramen was illustrated as fully enclosed. If the pictures I've seen of the
actual specimen are trustworthy (I know, a big if, but check it out), the
pubic foramen is bounded by a hook (Norman's _Illustrated Encyclopedia of
Dinosaurs_, pg. 67). The ischium compares favorably with that of _Sinraptor_
(although it looks like the obturator flange is obscured behind the femur).
> On the other hand, I agree with you in this one case. Marsho seems
> likely to be a carnosaur. Now, if you wanna wrangle, we can talk
> _Stokesosaurus_, but check the archives first...
Looks rather similar to _Megalosaurus_ to me, although it also bears a
passing resemblance to tyrannosaurids (unlikely given the time frame) and to
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