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Re: Tyrannosauroids Imploding Further

Jaime A. Headden wrote-

> Furthermore, the lectotype tooth of *Aublysodon mirandus*
> appears to be a mesial maxillary crown,

No, the lectotype is a premaxillary tooth.  The supposed premaxillary tooth
of A. molnari is the first maxillary tooth though.

> and data is presented to show that
> serrations appear during ontogeny in the taxon,

Actually, the only "data" the authors give for this is saying "The
nondenticulate condition of the front teeth is not distinctive and  appears
to reflect immaturity, as in other theropods such as Velociraptor (e.g. IGM
100/972; Norell et al., 1994)."  Which is rather weak, especially since the
TWG now refer the relevent skulls to a troodontid (Byronosaurus?), not

> --Tyrannosauroidea
>   `--+--Dilong paradoxus
>      `--+?-Iliosuchus incognitus
>         |?-Stokesosaurus clevelandi
>         |?-Stokesosaurus? andrewsi

What is this taxon?

>   Carr and Williamson have several new species in prep, including two
> western NA tyrannosaurs and one Alabama one,

The latter is named somewhere online. :)

> But the clear extensive species of Asian tyrannosaur, most based only on
> teeth, and thos from Canada and NW USA (*Deinodon,* *Aublysodon,*
> *Tyrannosaurus,* *Tarbosaurus,* *Gorgosaurus,* *Albertosaurus,*
> *Proedeinodon*) all appear to be nomina nuda in the same vein as *A.
> mirandus*

I wouldn't be so quick to judge.  This paper itself describes apomorphic
dental characters of different tyrannosaurid taxa (mesial carina reaches
crown base in Daspletosaurus; "in Daspletosaurus torosus and Tyrannosaurus
rex, the lingual surface of each of the third left and right maxillary
crowns in LACM 28471 bear a prominent apicobasal ridge that creates a crease
adjacent to the mesial carina"; etc.).  So once horridus, periculosus and
such are studied, it may be possible to refer them to known taxa.

Mickey Mortimer
Undergraduate, Earth and Space Sciences
University of Washington
The Theropod Database - http://students.washington.edu/eoraptor/Home.html