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Re: feathers and spines--another alternative?
Cory Pittman wrote:
> Regardless of whether they arose as modifications of scales, scutes or
> a novel structure, feathers first evolved as barbed, erectile, defensive
> spines. And, they did so in an ectotherm.
I've had much the same musing from time to time. Australian echidnas
have spines longer than the hair in between, to they appear spiny. The
giant echidnas from Papua New Guinea live at high altitiudes, and so
have hair longer than their spines, making them look like big cuddly
puff balls. If they were to evolve a new form of defense so they didn't
need spines (say, learned to climb trees...), would they lose their
spines and retain only the insolatory hair?
Perhaps pin feathers are a case of ontogeny recapitulating phylogeny?
(IE. Ancestoral "feathers" began as defensive spines, and developed from
there, a process that is mirrored in the developmental stages of modern
I love the smell of speculation in the morning.
Dann Pigdon Australian Dinosaurs:
GIS Archaeologist http://dannsdinosaurs.terrashare.com
Melbourne, Australia http://www.alphalink.com.au/~dannj/