[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Revising Hou et al, 96 (very very long)
----- Original Message -----
From: "Mickey Mortimer" <Mickey_Mortimer111@msn.com>
Sent: Wednesday, April 24, 2002 9:46 AM
> > <6. Elongate distal chevrons and prezygopophyses
> > Also in Microraptor, which is even more bird-like (but still thought
> > be a deinonychosaur by many).>
> > Yes, and for many other reasons, including the pes construction (an
> > apparent troodontid + dromaeosaurid synapomorphy, along with pedal digit
> > II features).
> That are all also found in Rahonavis, a probable avialan.
Just OOC... suppose I came up with
What must I ignore to pretend that this is very easy to find if some
character polarities are set "the right way"?
Several very birdlike features of *Rahonavis* must be convergent in
any case. Examples are the scapula-coracoid joint that confuciusornithids
don't have, the slow growth (like Enantiornithes and *Patagopteryx*) that
confuciusornithids don't have either, and the quill knobs that, it seems,
appear somewhere in Euornithes and disappear in tinamous and *Piksi* (free
pdf -- sample issue -- at www.nrc.ca/cisti/journals/sample/e01-057.pdf!!!)
> > <unserrated premaxillary teeth;>
> > Functional, irrelevant, and convergent with other taxa; perhaps diet
> > related.
And, in addition, perhaps plesiomorphic (also seen in compsognathids and
> No data is irrelevent, most morphological synapomorphies are functional.
> I'm sure dental characters are diet-related. You don't see people
> the D-sectioned teeth of tyrannosaurids, despite the fact they were
> convergent with Pelecanimimus, diet-related and functional.
As has been explained onlist, the exact shape of tyrannosauroid pmx teeth is
> > <boomerang-shaped furcula;>
> > Not in *Sinornithosaurus*; its is rather shallow in aspect when viewed
> > from the "top/rostral".
> It's thinner than Archaeopteryx, but does have the same morphology. Very
> different from Velociraptor.
Likewise, *Bambiraptor* has a boomerang-shaped one, and so do
oviraptorosaurs, no? The furcula seen in *Velociraptor*, with its straight
rami, is IMHO rather apomorphic anyway.
> > <fibula <20% of tibia width.>
> > Size related.
> Which is why Compsognathus lacks it..... we all know how huge it was. ;-)
Erm... err... maybe functional, related to the secondarily rather short legs
> > other features that support the Deinonychosauria and the close
> > association of *Sinornithosaurus* to Dromaeosauridae:
> > 1. pedal phalanx II-2 with elongation of the ventral edge of the
> > proximal articular facet, providing the dorsal extension of the ungual
> > phalanx.
> Like troodontids and Microraptor?
Why not? :-)
> > 2. pedal phalanx II-3 ungual forms raptorial claw.
> Like troodontids, Rahonavis and Microraptor?
Why not, see above? :-)
> > 3. elongate posterior flanges of the metatarsals II and IV, converge
> > nearly converge at the midlength.
> Like troodontids, Microraptor, Archaeopteryx and probably Rahonavis?
Same! :-) In the Ostrom Symposium Volume, Archie and Pygostylia share damn
few features, and all of those are pretty ambiguous. Actually I wonder why
Archie is still hailed as their closest relative by so many people. (Where
does it come out in DA, before I get that book?)