Arctometatarsalia {Ornithomimus <- Neornithes} is still
plausible, and does not require tyrannosaurs in its content,
though this is what Holtz suggested in 1994 and 1995 (in
Sereno's 1999 phylogeny, alvarezsaurs as ornithomimosaur
relatives would be members of Arctometatarsalia (a stem) which
would contain Ornithomimoidea (a node)); data seems to point to
the synapomorphies being tyrannoraptoran {Tyrannosaurus +
Neornithes} in nature that were reversed in maniraptorans,
perhaps with Troodontidae having preserved the last vestiges of
the leg and braincase that were lost in the dromaeosaur,
oviraptorosaur, therizinosaur, and avian lineages.
Maniraptoriformes == {Ornithomimus + Neornithes}.
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Jaime A. Headden
Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
Where the Wind Comes Sweeping Down the Pampas!!!!
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