RE: Dinosaur Feathers (was RE: Bambiraptor complete!)

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Alan Kellogg
>
> After following the discussion for a bit a question arose. Among
> those species that bore plumage, what sort of plumage did they have?

A variety.  The most primitive forms have simple filaments to simply
branched structures.  More derived forms have broad feathers on the arms and
tail.  As in modern dinosaurs (aka birds: sorry, Eric, but you will
eventually have to deal with this discovery...) any individual can have
multiple different types of feathers on different parts of the body at the
same time: see http://research.amnh.org/vertpaleo/dinobird.html and click on
the various images along the bottom for closeups.

> What sort of display plumage did they have, and when?

Damned if anyone knows!  This is where your time machine would come in
handy!!  We honestly do not know the function of the feathers of different
non-flying dinosaurs, and of course (as with modern animals) any structure
could have multiple functions.  As yet, no non-avian dinosaur has
demonstrated feathers which are almost certainly strictly display (like
peacock's tail, or the long streamers of some specimens of the Cretaceous
bird _Confuciusornis_).

> Some of the specimens we have found could have been
> bearing display plumage at the time of their death, and not the
> feathers they wore during the rest of the year.

Bingo!!  Add to this changes with ontogeny.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796