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Re: Did Feathers Evolve for Dispaly? We Still Don't Know!



Perhaps observing hairy pterosaurs may help us deciding... There seem
to be a large number of pterosaurs with pycnofibres. Are the
pycnofibres present only around the body profile in pterosaurs? And,
are there pterosaurs, in different death positions (i.e., some
dorsoventrally flattened, some others laterally flattened), preserving
hair only around the boundaries of the fossil? This would suggest
we do not have reason for supposing there is no hair outside of the
rims of the fossil.


2010/1/28 Thomas R. Holtz, Jr. <tholtz@umd.edu>:
> Tim Williams wrote (okay, quoted):
>
>> "Furthermore, we now know that the simplest feathers in dinosaurs such as
>> _Sinosauropteryx_ were only present over limited parts of its body – for
>> example, as a crest down the midline of the back and round the tail –
>> and so they would have had only a limited function in thermoregulation."
>
> Actually, I am not at all convinced that these were present only over
> limited parts of the body. The situation is such that we only get
> preservation where sediment meets sediment, and thus only in halos around
> the organism. Unfortunately we can't tell if these are the only fuzzy
> parts, or simply the lucky fraction of the fuzzy parts that get preserved.
>
> --
> Thomas R. Holtz, Jr.
> Email: tholtz@umd.edu   Phone: 301-405-4084
> Office: Centreville 1216
> Senior Lecturer, Vertebrate Paleontology
> Dept. of Geology, University of Maryland
> http://www.geol.umd.edu/~tholtz/
> Fax: 301-314-9661
>
> Faculty Director, Earth, Life & Time Program, College Park Scholars
> http://www.geol.umd.edu/~jmerck/eltsite/
> Faculty Director, Science & Global Change Program, College Park Scholars
> http://www.geol.umd.edu/sgc
> Fax: 301-314-9843
>
> Mailing Address:        Thomas R. Holtz, Jr.
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