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Re: Introducing Mahakala omnogovae, little dromaeosaurid of Mongolia
----- Original Message -----
From: "Thomas R. Holtz, Jr." <email@example.com>
Subject: Introducing Mahakala omnogovae, little dromaeosaurid of Mongolia
Inclusion of the data into the latest AMNH Theropod working group matrix
reveals it to be the basalmost dromaeosaurid, despite its age. More
dromaeosaurids are better resolved phylogenetically than earlier versions
this matrix: a clade comprised of Unenlagiinae (Shanag + Buitreraptor +
(Rahonavis + Unenlagia)) + Sinornithosaurus + Microraptorinae (Microraptor
gui + Microraptor zhaoianus + Graciliraptor), and a clade of "classic
dromaeosaurids": Velociraptorinae (Tsaagan + (Saurornitholestes +
(Velociraptor + Deinonychus))) + Dromaeosaurinae (Adasaurus +
+ (Achillobator + Utahraptor)).
The resolution is further increased by the fact that the tree in the paper
is not the strict consensus. It is the Adams consensus (of 1296 trees).
Supplementary information, p. 27: "Strict consensus differs in reduced
resolution within the *Adasaurus*, *Dromaeosaurus*, *Achillobator*,
*Utahraptor* clade due to lability in placement of *Dromaeosaurus*; reduced
resolution within the *Unenlagia*, *Rahonavis*, *Buitreraptor*, *Shanag*
clade due to lability in placement of *Shanag*; and reduced resolution
within the oviraptorosaurs more derived than *Incisivosaurus gauthieri*."
The Velociraptorinae-Dromaeosaurinae split is real, though, and so are the
positions of *Jeholornis* and *Jinfengopteryx*.
Given the size of the basal members of each clade ((Archaeopteryx +
Jeholornis) + Pygostylia); (Mei + Sinovenator) + Jinfengopteryx;
the basal eumaniraptoran would seem to be a small Archaeopteryx-sized
Not just "seem". They calculate that using a sophisticated method that is...
completely different from that used in Laurin 2004 (body size evolution of,
uh, limbed vertebrates, Devonian to Middle Permian, Systematic Biology) and
my M.Sc. thesis. :-o Will be interesting to compare. It apparently doesn't
take branch lengths into account.