Re: Sereno's (2005) new definitions

[David Marjanovic <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Jaime A. Headden" <qilongia@yahoo.com>
Sent: Thursday, December 22, 2005 7:57 AM

> As Tim said, the holotype tooth of
> *Troodon formosus* is not directly comparable to the types of any other 
> North
> American troodontid except for *Pectinodon bakkeri*, which is very 
> distinct in
> form to *T. formosus*. Contra Marjanovic's statement about correspondence 
> of
> the teeth with those of *Saurornithoides*, only *P. bakkeri* is closely
> corespondent, that of *T. formosus* is not, arguing we would need to find 
> _in
> situ_ teeth identical to the type to more directly infer it's nature.

I never said any such thing. What I said was that we can be sure that the 
holotype tooth of *T. formosus* belongs somewhere inside the clade currently 
called Troodontidae (and not very close to its root).

(Even without actually including the tooth as an OTU in an analysis, we can 
look for the autapomorphies of all troodontid clades and check which are 
present and absent in the tooth, thus determining into which clade *T.* must 
belong -- even if that clade is rather large.)

>  I actually favor the classical correspondence of the use of Troodontidae,
> Dromaeosauridae, their anchoring except as noted above, and except to use 
> birds
> as external specifiers for each.

If we use *Saurornithoides mongoliensis* but not *Troodon formosus* as an 
internal anchor, the name should be Saurornithoididae and not Troodontidae.

> Tetanurae should be used only to include birds but
> exclude carnosaurs in the broad sense (i.e., that of Padian, Hutchinson 
> and
> Holtz, 1999), rather than get pedantic about their exclusion.

Do you mean Coelurosauria instead of Tetanurae, or ceratosaurs instead of 
carnosaurs?