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

RE: maxillary fenestration & WHAT are "segnosaurs"?

  where all the theropod features of *Beipiaosaurus* are listed
from _only_ the main and absolutely contiguous block. Not even
the raptorial arms, skull, shoulder girdle, etc. are included,
which only chock the list higher, including [some overlap here]:<<

Que? What skull of Beipiaosaurus? I know of only the jaw.

 >> Rostral process of postorbital elevated, turned dorsally
(coelurosaur and maniraptoran respectively); palatines do not
contact sagittally, ectopterygoid does not contact jugal or
maxilla (oviraptorosaur), vomers more than 50% skull length;
maxillary teeth caudal extent rostral to orbit; lachrymal with
broad dorsal exposure on skull roof; pneumatic quadrates
(maniraptoriform), extensive antorbital fossa on lachrymal;
cnemial process apex turned down, ascending process of the
astragalus greater in hieght than corpus of astragalus, fibular
crest (theropoda) on tibia; humeral head/condyle emarginated
from proximal end by shallow channel (groove), scapula dorsal
and ventral margins parallel without distal expansion
(strap-like), coracoid and scapular margin strait; only three
metacarpals, semilunate carpal block also trochleate, furcula,
metacarpal I less than the width of metacarpal II, no distal mcI
"twist" (sensu Galton and Bakker, 1984), manal claws not
expanded ventrally, distal manal phalanges longer than proximal
(tetanuran, for the most part), ulna/radius distal articulation
inset and immobile, distal humeral condyles face cranially;
cervicals extensively pneumatic, more than three sacrals, which
are pneumatic, neural arches on cervicodorsals and dorsals
higher than centra; opisthopubic pelvis (wierd character), open
pubic obturator foramen, obturator prong triangular (a
distillation of coelurosaur and maniraptoriform), pubic apron
reduced to less than 1/2 pubic length (maniraptoran).,<<

Could any of these have evloved from a more primitive prosauropod? I don't
have the time or expertese to go through this.

I've just a gut felling right now
(and could be wrong, I guess).