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Re: Huge morphological analysis reconfirms deep branch relationships among Squamates.
Very cool paper, and I agree about the quality of the character
So do I. It's also cool to have both Gauthier and Rieppel among the authors.
Though having 68% more characters than Conrad (2008),
(Though not "just under 1000 characters". The abstract says 610
characters, which result in a total of 976 apomorphies all over the tree.)
it also has thirty less taxa.
Are there any fossils that Conrad included and the new study lacks? (I
don't have access to the paper today. Maybe I'll go to the museum
Note both group snakes with two other clades of limbless squamates-
amphisbaenians and dibamids, a group which Gauthier et al. call
Krypteia. In Conrad these nest within limbless skinks whereas in
Gauthier et al. they nest in anguimorphs with the legless Anniella.
<Picard & Riker double facepalm>
Molecular analyses place dibamids as the basalmost living lizards,
Dibamids and/or geckos, no?
amphisbaenians sister to lacertids,
Beautifully supported by the fossil record, I must add.
and snakes as sister to iguanians+anguimorphs.
No. Molecular studies apparently can't resolve the
Iguania-Anguimorpha-Serpentes trichotomy; different analyses find
different resolutions, and the internodes are always scarily short.
Lee's recent combined analysis, however, finds Anguimorpha and
Pythonomorpha (of which Serpentes is the crown-group) as sister-groups.
Similarly, the new Gauthier et al. analysis has mosasaurs as the most
That's hard to believe. Where do all the aigialosaurs, dolichosaurs,
pontosaurs and whatnots come out?
Where are *Marmoretta* and *Huehuecuetzpalli*?
Conrad tried to test this by deleting all taxa except limbless
burrowers (snakes are basally burrowing in his analysis, and notably
the burrowing Sineoamphisbaena is sister to Anniella+Krypteia in
Gauthier et al.'s), and claimed because Krypteia still emerged,
limbless burrowing characters weren't responsible.
How about looking for correlated _characters_ instead and -- not
removing, but merging them?
(I speak from experience when I say characters correlated to others
shouldn't simply be removed. In fact, I'll publish on that. Short
version: comparing characters is a great way to find mistakes in the
coding of all of them.)