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Re: Different take on BCF



At 14:10 3/12/96 -0500, Tracy Ford wrote:

>No, the problem is assuming that birds evloved along only one line.
>Both Enantiornithine and Ornithiane birds are known from the Early
>Cretaceous. Since both are known, there are two different lines of
>birds in the Early Cretaceous. The line couldn't produce both birds
>from only one line.  It's impossible.

No, it's not impossible, you're wrong. You can have just a line from
_Archaeopteryx_ (the most primitive bird we knows about) to some kind of
primitive bird/s, the Ornithothoraces (like _Iberomesornis_), and then, a
dichotomy, with the Enantiornithes in one branch and the Ornithurae in the
other one. What's the problem with that? I can't see it (you can read the
Chiappe's paper in Nature about the first 85 million years of avian evolution).

Nino.
Bernardino P. Perez-Moreno                   Fax: 34-1-3978344
Unidad de Paleontologia                      E-mail: Nino@uam.es
Departamento de Biologia                     Phone: 34-1-3978139 
Facultad de Ciencias
Universidad Autonoma de Madrid
28049 - Madrid
SPAIN