[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Theropod polyphyly vs BCF
I think what he is arguing is that the theropod bauplan evolved several
independently in nondinosaurian archosaurs, and that we're lumping all
lineages into Theropoda because of their homoplasies. This isn't BCF, since
BCF assumes dinosaurian and theropod monophyly.
My response was somewhat tongue-in-cheek. Yep, what he is saying that the
bird-like theropods are more closely related to _Longisquama_ than to other
theropods, and most of the similarities are due to convergent evolution
between two independent lineages. The former lineage was favored to survive
into the Cretaceous as a result of some end-of -Jurassic "minor holocaust"
(an oxymoron?). The "dogma", of course, is that the Theropoda is
The similarity to BCF is that an arboreal _Longisquama_-like ancestor gave
rise to ground-dwelling bird-like theropods.
Personally, I'm ready to believe that many Cretaceous maniraptorans may have
evolved from a volant pre-archaepterygid theropod (which would explain the
feathers in _Caudipteryx_ -it's secondarily flightless). But the fossils we
currently have available don't support that hypothesis.
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com