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

Re: Geeze, yet another stupid question.



In a message dated 96-11-22 02:35:45 EST, jpoling@dinosauria.com (Jeff
Poling) writes:

>    Dinosauria without birds is paraphyletic.  But what are birds without
> dinosaurs ... polypheletic?  The definition of polyphyletic, it seems to me,
> wouldn't apply in this case.  So what is the proper term? 

In most BADD taxonomies and in paleornithological taxonomies in which
dinosaurs are considered unrelated to birds, "birds without dinosaurs" is the
same as "birds," namely, a monophyletic taxon (Aves: single common ancestor
and all its descendants).

In BCF taxonomy, "birds without dinosaurs" is paraphyletic, since it includes
the single common ancestor but excludes some of the descendant groups.