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Re: flying Archie

David Marjanovic (david.marjanovic@gmx.at) wrote:

<*Rahonavis* had a joint between the scapula and the coracoid, unlike
*Archaeopteryx*, *Sapeornis* or *Confuciusornis*.>

  There might be a difference in not having a fused scapulocoracoid and
actually having a mobile joint between the two bones, in animals without the
fusion. While modern birds today preserve a semi-condylar joint surface between
the two bones, it is possible that this feature did not develop prior to a
certain point in the evolution of Aves, and may not have included many Mesozoic
"birds" at all, including *Rahonavis* -- which may just be a [non-avian]
dromaeosaur, anyway. IF it had the joint, this might argue either for
parallelism, or a latent presence of the feature that was lost (repeatedly) in
various lineages prior to the advent of the
respiratory-assisting/flight-assisting structure in extant birds.


Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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