RE: When Did Theropods Become Feathered?--Evidence for Pre-Archaeopteryx Feathery Appendages

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Nick Gardner
>
> MARTIN KUNDRA 4 T (2004). When Did Theropods Become
> Feathered?--Evidence for Pre-Archaeopteryx Feathery
> Appendages.  Journal of Experimental Zoology (Mol Dev
> Evol) 302B: 1-10.
>
> ABSTRACT Filamentous impressions associated with
> locomotive theropod tracks in the Lower Jurassic
> Turners Falls Formation of western Massachusetts,
> U.S.A. represent the oldest evidence of feathered
> dinosaurs. Feather impressions are preserved with
> sitting traces which bear integumentary structures
> along the outlines of the pre-pubic and ischiadic
> impressions.

A rather unfortunate piece, as the work of Anthony Martin (at the NE/SE
regional GSA meeting) obliterates the "feather impression" hypothesis for
this specimen.  Unless, of course, we wish to accept that wormtrails,
toe-drag marks, and such also were feather-bearing...

Kundrat at least accepts a toe-drag reason for the "feathering" of
"Plesiornis".

Note that Martin DID point out that there was nothing about the specimen
which demostrated that it wasn't feathered, only that the structures being
interpreted as "feather impressions" were actually algal mat drags.


                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
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