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Re: Aquatic Origin of birds (was Aquatic spinosaurs (was Size of *Neoceratodus africanus*))



This was discussed some time ago on this list. I think the acronym for
it was FUCHSIA (flight underwater, continued, however strange, in air).

Searching the archives for thsi should turn up more.

> On May 3, 2009, at 10:40 PM, Amtoine Grant wrote:
> >Correct me if I'm wrong, but weren't the earliest specimens of Archaeopteryx
> >found in aquatic  deposits from ecosystems relatively devoid of trees?
> >Factoring in Archie's crocodilian/spinosaurid-like (pisciviorous?)
> >conical-esque teeth and the possible non-feathering of the humerus, this
> >theory is only held back ever so slightly by the fact that the tail was
> >already fully feathered.
> 
> The aquatic origins hypothesis is interesting in some ways, but doesn't have
> much going for it, at this point.  Among the problems it faces is the fact
> that Archaeopteryx has neither the hindlimb structure nor the forelimb
> structure that one would expect in a diving taxon (that is, it does not
> possess hindlimbs adapted to hindlimb propelled swimming, nor forelimb spars
> indicative of forelimb-propelled swimming).  The only thing that is at all
> "aquatic" looking in Archaeopteryx, by modern standards, is is relatively
> thick appendicular cortices and lack of appendicular pneumaticity (these go
> hand-in-hand).  That, however, appears to be plesiomorphic for Archaeopteryx,
> and so does not mean the same thing as the secondary reductions in
> pneumaticity seen in living diving birds.
> 
> Cheers,
> 
> --Mike
> 
> 
> Michael Habib, M.S.
> PhD. Candidate
> Center for Functional Anatomy and Evolution
> Johns Hopkins School of Medicine
> 1830 E. Monument Street
> Baltimore, MD 21205
> (443) 280-0181
> habib@jhmi.edu
> 
> 

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