Re: Ornithomimid beaks

["Mickey Mortimer" <Mickey_Mortimer11@msn.com>]

T. Mike Keesey wrote-

> Beaks appear to have evolved at least three times within _Theropoda_ (all
> within _Maniraptoriformes_): once in _Ornithomimosauria_, once in
> Clade(_Oviraptor_ <-- _Passer_) (which includes _Therizinosauria_), and
> once within _Aves_. It is not certain whether _Avimimidae_ and
> _Alvarezsauria_ belong to one of these groups or evolved beaks
> independently.
>
> Toothlessness evolved within each of the three aforementioned clades, once
> in _Ornithomimidae_, once in Clade(_Oviraptor_ <-- _Therizinosaurus_), and
> at least three times within _Aves_ (within _Confuciusornithidae_,
> _Enantiornithes_, and _Carinatae_).

I generally assume all toothless theropods had beaks.  Is there some reason
this might not be true?  Assuming this is true..... Shuvosaurus,
ornithomimosaurs, Erlikosaurus, oviraptorosaurs, Avimimus,
confuciusornithids, Boluochia, Gobipteryx, Nanantius? valifanovi and
ornithurines all have beaks of some sort.  I don't know if we should think
of "enigmosaurs" as evolving a beak once, as basal oviraptorosaurs (eg.
Caudipteryx) only have premaxillary teeth, while Erlikosaurus only lacks
premaxillary teeth.  I never thought of mononykines having beaks before, but
I suppose their tooth distribution is similar to Pelecanimimus.

Mickey Mortimer