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Re: pneumatic bones



----- Original Message -----
From: "Mickey_Mortimer" <Mickey_Mortimer11@email.msn.com>
To: <dinosaur@usc.edu>
Sent: Monday, March 05, 2001 6:44 AM
Subject: Re: pneumatic bones


> David Marjanovic wrote-
>
> > > Two obvious ways to
> > > cast doubt on the theory would be to show basal members of either
group
> > > lacked the character, or show it was present in a competing sister
group
> > to
> > > pygostylians as well.
> >
> > Is there any such evidence?
>
> Yes.  Remember, basal oviraptorosaurs (Caudipteryx, Microvenator) lack
> caudal pleurocoels.  I don't know of any reports of pneumatic caudals in
> non-neornithine birds.  Remember Achillobator has caudal pleurocoels as
> well.

thanx!

> > Pneumaticity in all dorsals also occurs in *Torvosaurus* and
*Sinraptor*,
> I
> > remember to have read (probably in the same abstract as above :-( ),
> whereas
> > *Allosaurus* has only 4 pneumatic dorsals (I don't know whether they
were
> > speaking of any pneumatic features or only of true pleurocoels).
>
> Straight from my "Details on Fukuiraptor" research........
> Taxa are listed with how many pairs of dorsal pleurocoels they have:
> Dilophosaurus (0), Ceratosaurus magnicornis (0), Ceratosaurus
dentisulcatus
> (6-7), Abelisauridae (11, all), Torvosaurus (13, all), Spinosauridae (5),
> Monolophosaurus (4-5), Piatnitzkysaurus (3), Sinraptor (4),
Yangchuanosaurus
> (2?), "Szechuanosaurus campi" (0), Acrocanthosaurus (11(+?), all?),
> Giganotosaurus (~8(+?)), Neovenator (13, all), Allosaurus (3),
Compsognathus
> (0), Tyrannosauridae (13?, all), Ornithomimidae (0), Microvenator (all?),
> Oviraptoridae (12, all), Alvarezsauridae (0), Avimimus (0), Troodontidae
> (0), Dromaeosauridae (12, all in Deinonychus, Bambiraptor, Unenlagia?; <7
in
> Velociraptor)

Impressive, interesting... but what about pneumatic fossae?

in the next post, HP Mickey Mortimer wrote:

> > There is a nice entry for *Bagaraatan*. HP Mickey Mortimer wrote some
> > months ago "told you it's interesting!"; indeed it is. Are there any
other
> > animals with that extra bone, the antarticular? Any with caudal centra
that are
> > hollow and thin-walled, but not pneumatic? Any with such a small angular
> > and big surangular? The unusual proximal rigidity of the tail is
considered an
> > adaptation for speed, but do ornithomimosaurs have something comparable?
> >         Glut puts it into "?Avetheropoda _incertae sedis_", I don't have
> > any better idea. Mantra time -- give me more fossils!!!
>
> Allosaurus also has an antarticular.  Where known, theropods seem to have
> had hollow caudal centra.  Examples include Ceratosaurus, Allosaurus,
> Coelurus and ornithomimids.  Oviraptorids have an even smaller angular.  I
> would place Bagaraatan as a non-eumaniraptoran maniraptoran.

thanx! :-)