Isn't keratin the albuminoid that forms the chemical basis both
feathers, nails, hair, and even horn? Dinosaurs had nails (thus keratin),
and I don't see why keratin for feathers should have been a problem, if
that's what someone is implying.
This is where we need Alan Brush! In the meantime, my understanding is
that reptiles (including birds) produce two types of keratin, alpha (which
we produce too) and beta (restricted to reptiles), and that feathers are
made of beta keratin. As the same is true for reptile scales and the
scutes of turtle shells, I hardly see how this could be used one way or the
other to determine the relationship of birds within Archosauria, but then
I've been wrong before....
--
Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2 mailto:ornstn@home.com