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re: Asilisaurus kongwe, the Oldest Avian-line Archosaur and the Early Diversification of Ornithodira



from:
Nesbitt, S.J., Sidor, C.A., Irmis, R.B., Angielczyk, K.D., Smith, R.M.H.,
and L. A. Tsuji. 2010. Ecologically distinct dinosaurian sister group shows
early diversification of Ornithodira. Nature. doi:10.1038/nature08718

<snip>Phylogenetic analysis places Asilisaurus kongwe gen. et sp. nov. as an
avian-line archosaur and a member of the Silesauridae, which is here
considered the sister taxon to Dinosauria. Silesaurids were diverse and had
a wide distribution by the Late Triassic, with a novel ornithodiran bauplan
including leaf-shaped teeth, a beak-like lower jaw, long, gracile limbs,
and a quadrupedal stance.<snip>

Any dino precursor with leaf-shaped teeth, a beak-like lower jaw and a 
quadrupedal stance has three strikes against candidacy for the avian lineage. 
These all denote offshoot characters from the recurved tooth, non-beak-like 
lower jaw, bipedal ancestor of birds and silesaurids

But then, if the paper says otherwise...

I'm seeing problems with the inclusion of basal taxa (pterosaurs, Lagerpeton) 
that are unrelated to the lineage of dinosaurs. Might be part of the problem.

David Peters
St. Louis