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Re: Science feather strength debate



On 11/15/2010 10:22 PM, Jason Brougham wrote:

If we accept for sake of argument that there were no tertials, and that
their absence negatively impacts the gliding capabilities of Archeopteryx,
then it seems all that is left is to quantify this impact.

Is the loss in gliding efficiency enough to prevent gliding, or merely
enough to make it less efficient? If Archaeopteryx had pretty low wing
loading then maybe it could glide quite nicely without high efficiency.

Lastly, perhaps Archaeopteryx's poor gliding potential is one line of
evidence that it flapped well. Though they may be decisive for gliding,
tertials are the least important feathers in flapping flight.

And perhaps inboard wing feathers are very poorly attached in birds that do not flap very well.

And are we also assuming that the shoulder did not constrain the upstroke? Why?

The feathers between the elbow and the armpit are much easier to pluck that the feathers distal to the elbow in all the individuals of all the species I have handled.

That does not prove that Arch. had feathers between the elbow and the body in life, and I see no reason to question the claim that these feathers are absent from the fossils.

I do see reason to question the claim that there is no scenario leading to the preservation of primaries, tail feathers and "dinofuzz", but non-preservation of the feathers along the humerus.

There is opportunity and need for science to be done, it seems to me -- measuring relative strength of feather attachment among species of varying flight styles, and observation of deceased birds under conditions similar to Solnhofen -- high salinity, warm anoxic water, and low energy, at least on the bottom.

How long does the body float? Surely there must have been some wave action on the surface as the various Archies decomposed enough to sink -- multiple scenarios could be practically tested there, too.

What is the relative buoyancy of different types of feathers under such conditions?

I remain moderately hopeful someone has already done something along these lines at some point in time.