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

RE: aviformes

Tom Holtz wrote:

We need the context for this.  "Aviform" means "bird shape".  Might you be
referring to Alan Feduccia's "avimorph thecodonts": his para-/polyphyletic
assemblage of diapsids including drepanosaurids like Megalancosaurus and
other taxa like Longisquama which he postulates were the arboreal ancestors
of birds?

And don't forget _Scleromochlus_, the third member of Feduccia's trinity of "avimorph thecodonts". You see, _Scleromochlus_ has long arms like a bird...

The reason why the term "avimorph thecodonts" is so nebulous and taxonomically meaningless is eloquently mentioned by Kevin Padian:


(Though I think _Megalancosaurus_ is best interpreted as arboreal rather than aquatic. Either way, its skeleton is manifestly unsuitable for it to be considered a likely proavian.)


Feduccia, A and Wild, R. (1993).  Birdlike characters in the Triassic
archosaur _Megalancosaurus_.  Naturwissenschaften 80 (12): 564-566.



Timothy J. Williams

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

Phone: 515 294 9233
Fax:   515 294 3163

Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp