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re: Chaoyangopterus



David Unwin wrote:

 Chaoyangopterus
lacks at least one key azhdarchid apomophy (highly elongate mid-series
cervicals) and seems to compare quite well (at least morphometrically
speaking) with Sinopterus which has been identified as a tapejarid,
generally recognised (at least by me and Kellner) as a basal
azhdarchoid.


>>>>>>

You might want to take another look at Zhejiangopterus. Neck cervicals
5-7 are only half the length of those in Quetzalcoatlus and most other
classic azhdarchids (most based on neck cervicals).

Chaoyangopterus appears to have a short striated premaxillary crest, ala
Huanhepterus, and the skull posterior is  sitting atop the pelvis, still
attached to the cervicals. Thus the cervicals series is much longer than
the torso and the skull is much longer than in Sinopterus, IMHO.

Finally, I'm still not convinced that tapejarids and azhdarchids are
sister taxa. Relatively short legs, short neck, big square sternal
complex, fused pelvis in the former. The opposite in the latter. Plus
the palate, occiput, manus and pedal patterns are dissimilar. There are
better sister taxa for each clade out there.

You did notice, I'm sure, that the antorbital fenestra is also higher
than the orbit in Anurognathus. It's a great homology. Not a great
synapomorphy.

David Peters
St. Louis