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Re: INTRODUCING Microraptor gui (or Cryptovolans pauli, or Microraptor pauli, or...)
Thomas R. Holtz, Jr. <email@example.com> wrote:
Xu et al. consider the elongated leg wing feathers as gliding supports, and
have a restoration of _Microraptor_ with
its leg splayed out to the side. I find this very questionable, given that
there is no particular evidence that _Microraptor_ to move into this
position (which in your typical dinosaur would require popping the femoral
head out of the socket).
No, I don't have any good alternative explanation for the elongated leg
feathers. Rudder? Aid in prey capture? Display? Genetic link by serial
homology with the arm feathers? Nevertheless, given the constraints of the
pelvic anatomy, I do not see how the leg feathers could be used as a
laterally-oriented flight surface.
Interestingly, both the fore- and hindlimb feathers of _Microraptor gui_ are
asymmetrical. As Xu et al. note, this suggests that the feathers were
designed to create an aerfoil (airfoil). Using modern gliding/parachuting
primates as a model (e.g. _Propithecus_), it may not be necessary for the
hindlimbs to be laterally-oriented in order to provide a surface capable of
generating lift during aerial leaps.
Also, if these critters were using their aerodynamic abilities to locomote
from trees to the ground (e.g. ambush hunting), they would presumably have
landed feet-first. This necessitates a more vertical orientation for the
hindlimbs during these short descents.
Ten years ago, Alan Feduccia proposed that sifakas (_Propithecus_) may
represent an evolutionary analog to an early stage in avian flight.
_Microraptor gui_ (?or _Cryptovolans pauli_) may represent a theropod
Feduccia, A. (1993). Aerodynamic model for the early evolution of feathers
provided by _Propithecus_ (Primates, Lemuridae). Journal of Theoretical
Hats off to William Beebe!
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