|
David Marjanovic wrote-
I've just got the Nature paper.
Microraptor has distally placed and long halluces (both more so than in
Archaeopteryx), but they are definitely not reversed. Of course, I
can't judge whether it may have been revers*ible*, and preservation is another
issue...
My statement was based on the coding of this
character in Xu et al.'s data matrix.
BTW, what arguments are there to exclude
alvarezsaurids from birds? The prokinetic skull of Shuvuuia seems
clearly avian to me.
They just never fall out as avians (Archaeopteryx +
Neornithes) in any of my cladograms (or the AMNH team's recent ones, Sereno's,
etc.). Alvarezsaurids have various primitive characteristics like short
coracoids, scapulae without triangular anteriorly projecting acromions,
ventrally directed glenoids and the lack of a proximodorsal ischial process
that combine with the more birdlike characters of some dromaeosaurs to
place them below Aves. At most, sometimes they're the sister group to
Aves, but my most recent phylogenies (with Microraptor added) place dromaeosaurs
above them and troodontids (which are the outgroup to Aves if
alvarezsaurs are closest). Sure, they also have a ton of bird-like
characters, but that's just how the current cladograms crumble.
Mickey Mortimer
|