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scales to feathers (was Dinogeorge Digest #7)



would feathers have direved from scutes, as we've seen on many LARGE
dinosaurs, or more traditionally reptilian overlapping scales as in the
tummy of snakes (which seem very similar to the larger scales across the
front of birds' feet), or flat scales such as on snakes' backs (and on
most of the rest of the birds foot)?

As I've mentioned to James C. off list-the very first featehrs would
most likely have been symmetrical as Nature LIKES bilateral symmetry.  I
couldn't tell you at what point asymetrical feathers would have first
shown up, meaning before gliding, before flight, during flight
(concentric development) or after flight was already in use.

-Betty Cunningham

Dinogeorge@aol.com wrote:
> Subj:   Re: FCF
> Date:   98-07-03 16:07:03 EDT
> From:   Dinogeorge
> To:     th81@umail.umd.edu, JNorton@MAILBOX.UNE.EDU
> 
> In a message dated 98-07-03 13:28:32 EDT, th81@umail.umd.edu
> writes:
> 
> << Actually, both BCF and the "standard model" bird orgin predict (or at
> least do not reject) the idea that feathers predate _Archaeopteryx_.  >>
> 
> Actually, I see feathers/featherlike dermal structures in the
> dinosaur/archosaur clade as far back as _Longisquama_. And I see keeled
> ankylosaur scutes and spines, stegosaur plates and spines, sauropod dorsal
> spikes, and other such dinosaurian dermal structures as probably deriving
> from the protofeathers of the ur-dinosaur. True feathers, of a kind we would
> recognize as feathers were we to see them fossilized, probably first appeared
> sometime during the Triassic in the theropod-bird clade. (Rank speculation of
> the most egregious kind, of course.)