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Re: Valley of the T. rex, Raptor Red, and Maniraptoran Tyrannosaurs
Nicholas Gardner wrote-
> `--Tyrannoraptora (T1)
> `--Tyrannosauroidea (T2)
> |--Basal Tyrannosaurids
> |?-"T." megagracilis (Dinotyrannus)
> |?-"T." lancensis (Nanotyrannus)
> `--T. rex
> (T1) semi-lunate carpal degenerates.
> (T2) tyrannosaur design appears and arctomet begins
> (T3) arctomet developed, specialized braincase features, etc.
> Anyone want to comment?
Mike Keesey covered the main points, but I have some things to add.
How can you place Stokesosaurus closer to tyrannosaurids than Coelurus based
on "tyrannosaur design appears" and "arctomet begins"? The first is
extremely vague to the point of being an invalid character. The second is
not only vague, but is unknown in Stokesosaurus, Eotyrannus and Itemirus. A
similar criticism could be made of your "arctomet developed" character
diagnosing Eotyrannus and Itemirus, but not Stokesosaurus. You must also
specify which "specialized braincase features" diagnose this group. These
would be interesting to hear as Eotyrannus' braincase isn't known and that
of Itemirus isn't any closer to tyrannosaurids' than Stokesosaurus' is, as
far as I know. But my knowledge of braincase anatomy is limited. Tom Holtz
would be able to comment on these tyrannosaurian technicalities better than