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BEAKS etc IN THEROPODS
On dinosaur beaks, Mike Lovejoy asked..
IIRC, in your Eotyrannus paper, Tyrannosauroidea is in
Maniraptoriformes. Does this mean you feel T-rex had a
beak? ( Not trying to be funny; this is a serious question.)
Tim already pretty much answered this, but same answer:
Maniraptoriformes is a more inclusive group than
Maniraptora, so if all maniraptorans are beaked, that doesn't
mean that all maniraptoriforms are. I don't think
tyrannosauroids were beaked, nor non-maniraptoriform
theropods like abelisauroids or allosauroids. Among non-
maniraptoran maniraptoriforms we know of course that
ornithomimosaurs were beaked.
It's well known that keratinized ridges, bosses, horns and
hornlets are thought to have decorated the skulls of
theropods (and other dinosaurs). A rugose surface texture
and low ridge of bumpy bone in _Eotyrannus_ and other
tyrannosauroids (though strangely not in _T. rex_ specimen
FMNH PR2081) suggests the presence of a mid-line
keratinous covering or series of bumps or hornlets. Since
Carr has shown that this is the case even in the smallest
tyrannosaurids (and by inference that tyrannosaurids had
bumpy keratinized nasals at all ontogenetic stages [FMNH
PR2081 notwithstanding]), was nasal bumpiness NOT a
secondary sexual characteristic?
We're having some second thoughts about 'keratinization' of
the nasals in _Eotyrannus_ however, simply because some
of the nasal foramina are both extremely large (see Text-
Fig. 9.32 in Naish et al. 2001) and open into what appears to
be a pneumatic recess within the body of the nasal unit.
Clearly _Eotyrannus_ actually had a huge inflatable nasal
sac like a hooded seal. That was a joke. I would say wait for
the paper but, the way things are going, I will probably
never get it written.
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