Re: Valley of the T. rex, Raptor Red, and Maniraptoran Tyrannosaurs

["T. Mike Keesey" <tmk@dinosauricon.com>]

On Thu, 20 Sep 2001, Nicholas Gardner wrote:

> New phylo-analysis produced this.
>
> --Maniraptora
>   |--"therizinosaur/oviraptorosaur" clade
>   `--Paraves
>      |?-Compsognathia
>      |--Eumaniraptora
>      |  |--Avialae
>      |  |  |--Aves
>      |  |  `--"Troodontoidea"

Why not just _Troodontidae_?

>      |  `--Dromaeosauria

_Deinonychosauria_

>      `--Tyrannoraptora (T1)

IIRC, _Tyrannoraptora_ is defined as Clade(_Neornithes_ +
_Tyrannosaurus_), so, in terms of content, it is the same as _Paraves_ in
this phylogeny, although it is a clade within _Paraves_ (the only known
one).

What traits support a _Tyrannoraptora_ excluding _Oviraptorosauria_ and
_Therizinosauria_. (Or, to put it another way, what traits place
_Tyrannosauroidea_ within _Paraves_?)

Has _Tyrannosauroidea_ been phylogenetically defined? If it has, it is
probably a stem-based clade, and thus would include _Coelurus_, according
to this phylogeny. (Why is _Coelurus_ here, anyway?)

>         |--Coelurus
>         `--Tyrannosauroidea (T2)
>            |--Stokesosaurus
>            `--+==(T3)
>               |--Eotyrannus
>               |--Itemirus
>               `--Tyrannosauridae

>                  |--Basal Tyrannosaurids

These may in fact be juveniles of tyrannosaurines.

>                  `--+--Albertosaurinae

May not be monophyletic. _Gorgosaurus_ and _Albertosaurus_ are usually
placed within _Tyrannosaurinae_, although the collapse of
_Aublysodontinae_ may force some re-thinking on that matter. Safest to
keep a trichotomy of _Albertosaurus_, _Gorgosaurus_, and _Tyrannosaurini_
(=your Tyrannosaurinae) for now, IMHO.

>                     `--Tyrannosaurinae
>                        |--Daspletosaurus
>                        `--+--Tarbosaurus
>                           `--Tyrannosaurus
>                              |?-"T." megagracilis (Dinotyrannus)
>                              |?-"T." lancensis (Nanotyrannus)

These two are likely young  _T. rex_.

>                              `--T. rex

> Does anyone know anything new about "Tyrannosaurus imperator"?

Probably better to call it "The Rigby Tyrannosaur" or something like that,
lest someone think "T. imperator" is an actual, published name. I
personally haven't heard anything new....

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