Re: "tooth plates"

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Jordan Mallon wrote-

> One of the
> pieces I happened upon while browsing was a set of maxillary bones from
> _Daspletosaurus torosus_.  While I was having a look at these bones, Dr.
> Holmes, who was there with me at the time, commented on these sort of
> "plates" that lined the inside edge of the maxilla, between the teeth.
> Since he didn't quite have an answer from them (theropods aren't his
> specialty), I was just wondering if anyone here knew what these "tooth
> plates" were used for, or how they funtioned.

Sorry I can't actually answer your question, but the correct term for the
structures is interdental plates.  They are known in many crurotarsans,
prosauropods and theropods at least.  Theropod examples include not only
tyrannosaurids, but also Dilophosaurus, Megalosaurus, Piatnitzkysaurus,
Monolophosaurus, Sinraptor, Dryptosaurus, Coelurus, Compsognathus,
Scipionyx, Ornitholestes, segnosaurs, Protarchaeopteryx, Bagaraatan and
Archaeopteryx.  Some theropods (Ceratosaurus, Abelisauridae, Torvosaurus,
Spinosauridae, Fukuiraptor, Carcharodontosaurus, Allosaurus, Neovenator,
Stokesosaurus, Eotyrannus) fused theirs together.  This has been reported
for deinonychosaurs (Dromaeosaurus, Deinonychus, Velociraptor,
Saurornitholestes, Achillobator) too, but some think they lost theirs.
Bambiraptor and Sinornithosaurus have a mix of fused and unfused plates.
Other theropods (Pelecanimimus, Shuvuuia, troodontids, Archaeornithoides,
post-Archaeopteryx birds) are classically thought to have lost them, but
this may have been through fusion as well.  Of course edentulous taxa lack
them.

Mickey Mortimer