[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: Gauthier and de Queiroz's Classification of Birds



David Marjanovic wrote:

>BTW, "parafeathers" are hollow, but not in the least filamentous, they
>are obviously epidermal appendages, but AFAIK nothing can be said about
>whether they were produced by follicles. So they wouldn't count.

Yeah, Mickey's post refreshed my memory on the parafeathers, parasheaths,
and paracalami ascribed to _Longisquama_.  That particular evolutionary
scenario belongs in the realm of the paranormal, IMHO.

> > _Carinatae_ = Clade("keeled sternum" in _Vultur gryphus_)
> >[snip] And  Confuciusornis and Ingenia with their slight ridge, is that a
>keel? 

And what do you do with _Archaeopteryx bavarica_ which (unlike _A.
lithographica_) has been described as having a small keel?

>Traditionally_ Carinatae is the opposite of Ratitae, like Neo- and
>Palaeognathae, just at different rank. The inclusion of *Ichthyornis* is
>a relatively recent phenomenon.

I'm not so sure about a more inclusive Carinatae being a recent phenomenon.
Cracraft (1986) split the Otnithurae into Hesperornithiformes and Carinatae,
the latter taxon defined by the presence of a sternal keel, and including
_Ichthyornis_ and Neornithes. Remember, also, that the absence of a keel
from ratites is a secondary loss, associated with loss of adductive function
in the forelimb.


Tim




------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163