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Re: If not "Raptors," then what?



--- John Conway <john_conway@mac.com> wrote:
> 
> On Monday, September 2, 2002, at 11:35  AM, T. Michael Keesey wrote:
> 
> > _Dromaeosauridae_ sensu Sereno (a stem-based clade excluding 
> > _Troodon_; I
> > forget what the internal specifier was, although by draft PhyloCode 
> > rules it
> > should be _Dromaeosaurus albertensis_) would work, and it might also 
> > include
> > _Microraptor_.
> 
> Umm... wouldn't this definition include birds, if they are closer to 
> dromaeosaurids than to troodontids.

Yep.

> Was there more to the definition to avoid this?

Nope.

This is a problem with both definitions, though. The node-based definition
could include _Aves_ if, say, _Velociraptor_ were closer to _Aves_ than
_Dromaeosaurus_.

> Or is the Deinonychosauria now so well supported that such a 
> possibility was not even considered? :-)

Possibilities should always be considered, IMHO, although _Sinovenator changii_
seems to have lent a lot of support to _Troodontidae_ as _Deinonychosauria_.

If I were calling the shots, I'd like to see definitions like these in effect:

_Deinonychosauria_ = Clade(_Deinonychus antirrhopus_ <- _Vultur gryphus_)

_Dromaeosauroidea_ = Clade(_Dromaeosaurus albertensis_ + _Troodon formosus_) in
_Deinonychosauria_

_Troodontidae_ = Clade(_Troodon formosus_ <- _Dromaeosaurus albertensis_,
_Vultur gryphus_, _Oviraptor mongoliensis_, _Therizinosaurus cheloniformis_,
_Ornithomimus velox_)

_Dromaeosauridae_ = Clade(_Dromaeosaurus albertensis_ <- _Troodon formosus_,
_Vultur gryphus_)

_Dromaeosaurinae_ = Clade(_Dromaeosaurus albertensis_ <- _Velociraptor
mongoliensis_)

_Velociraptorinae_ = Clade(_Velociraptor mongoliensis_ <- _Dromaeosaurus
albertensis_) in _Dromaeosauridae_

A case could also be made for declaring _Troodon formosus_ dubious, and using
_Saurornithoides mongoliensis_ and _Saurornithoididae_ instead of _Troodon
formosus_ and _Troodontidae_.

The node-based definition doesn't seem as useful to me as the stem-based one
(unless of course, _Troodontidae_ are not _Deinonychosauria_....)

I suppose it'll be some time before terms and definitions really become
cemented, though, and the definitions presented here could turn out to be lousy.

=====
=====> T. Michael Keesey <keesey@bigfoot.com>
=====> The Dinosauricon <http://dinosauricon.com>
=====> BloodySteak <http://bloodysteak.com>
=====> Instant Messenger <Ric Blayze>
=====

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