Re: Psittacosaur tail structures

["Jaime A. Headden" <qilongia@yahoo.com>]

Okay, I read the days mail before I set to writing this, to make sure
I wasn't repeating anything ... besides the dead horse that I will
bring up....

Ken Kinman (kinman@hotmail.com) wrote:

<(even wing feathers would have been initially thermoregulatory, as
favored by Tom Hopps and others).>

  Not entirely accurate. Hopp and Orsen's theory, not bandied about
as much as it should, suggests that they are not intended to regulate
the animal's own thermogenesis, but to regulate ambient temperature
of the nest, as an umbrella, and only secondarily acheive
aerodynamics. They are not thermoregulatory in the sense of body
"feathers".

<If this stage occurred in early dinosauromorphs, it would perhaps
make balancing problems (brought up by Jaime Headdin) from loss of
part of the tail even less of a problem for my hypothesis. Such a
predator evasion strategy would have worked especially well in forms
that had long slender tail tips (wiggly, but with little mass).>

  Err ... this kind of tail would have had no balancing capabilities,
having little mass or inertial/impetus/balance control, and the same
hold true for any extra-integumentary structures like protofeathers,
these in *Sinosauropteryx* being hollow filaments forming a small,
fan-like spread. The implication is that of aerodynamics, or display,
rather than any "lure" or weak point to be snapped at. Again, dead horse.

=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

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