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Re: A critique of Sullivan's pachycephalosaur paper,

----- Original Message -----
From: "Michael Mortimer" <mickey_mortimer111@msn.com>
Sent: Tuesday, June 20, 2006 7:42 AM

Sullivan's diagnosis for Pachycephalosauridae reads like one of those
classic 'diagnoses' from the 1950's that lists symplesiomorphic or variable
characters in addition to synapomorphies. "Ornithischian dinosaurs with
thickened, fully-flat
or incipiently to fully-domed frontoparietals." So... the thickening is all
that needs to be mentioned then. "Supratemporal fenestrae absent to
well-developed." Uh... this would exclude which states now?

This is apparently not _intended_ to be a diagnosis (or "definition"). It is a description, at best a determination key. "If you see an animal that fits this description, it probably is a pachycephalosaurid."

What it could actually be good for is another question...

[...] detailed evaluations of "Troodon" bexelli and Heishansaurus