Avians and their Kin

[Dino Guy and Computer Gal <gbabcock@best.com>]

The earliest known articulated maniraptoran theropods, _Microraptor_ and
_Sinornithosaurus_ (right?), are also apparently the most anatomically
bird-like dinosaurs (undescribed Liaoning specimens notwithstanding).
This makes sense whether the most recent common ancestor they share with
modern birds (or Neornithes if you like) is avian or not, because either
way the later flightless maniraptorans we think of as non-avian
theropods would most likely be more derived than the maniraptorans
nearer the common ancestor (except for character reversals).

Questions:

Given the fossil record as it is currently understood, what criteria can
we apply to objectively determine whether the preponderance of evidence
at hand supports or refutes the hypothesis that oviraptorosaurs,
dromaeosaurs, and troodontids are secondarily flightless (as per Gregory
S. Paul)?  Where do therizinosaurs fit in?  And what of _Mononykus_ and
its friends?

   Ralph W. Miller III   ralph.miller@alumni.usc.edu

Squawk!  I'll read Paul's book when it comes out.