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RE: Validity of Alioramus



Speaking of problematic tyrannosaurids, what is the current view of 
Nanotyrannus?  I have examined the actual specimen, and it sure doesn't look 
like just a juvenile T. rex to me!  However, I am far from being able to give 
a qualified opinion...thus I ask how others feel about it being a valid taxon?

Regards,
Randall Irmis

>===== Original Message From Mickey_Mortimer11@msn.com =====
>Tim Williams wrote-
>
>> _Alioramus_ an immature _Tarbosaurus bataar_?  I'm willing to believe that
>> _Shanshanosaurus_ might be a young _Tarbosaurus_, but _Alioramus_ looks as
>> good as gold to me.  Can anyone set my mind at ease?
>
>Well, there's always Tom's analysis on the Tree of Life.  He separates
>Gorgosaurus, Albertosaurus, Daspletosaurus, Tarbosaurus and Tyrannosaurus
>from Alioramus because of the following synapomorphies lacking in the
>latter.
>
>Maxillary tooth count 13 or fewer
>Postorbital dorsal surface with enlarged bump in adults
>Supraoccipital excluded from foramen magnum margin
>Vertical depth of caudal portion of dentary twice or more as deep as depth
>at symphysis
>Dentary tooth count 15 or fewer
>Lateral teeth incrassate (cross-section greater than 60% as wide
>mediolaterally as long craniocaudally)
>
>Mickey Mortimer