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Re: COMPSOGNATHUS FEATHERS



Pete Buchholz <Tetanurae@aol.com> wrote:

I am not sure if it's all that clear Compsognathus lacked feathers. The specimen, as it is, doesn't preserve any skin to speak of. So as they say, absense of evidence is not evidence of absense.

Yep, I'll go along with that. What I should have specified is that the absence of feathery integument in _Compsognathus_ if *real* would indicate sedondary loss, considering its phylogenetic position.


Most of the feathers preserved in Archaeopteryx are the large primaries on the wings and tail. As far as I know, none of the softer contour feathers are preserved in any specimen of Archaeopteryx.

This is a sore point, since according to some sources the Berlin specimen of _Archaeopteryx_ once showed feathers (albeit faint) elsewhere on the body (neck, torso, leg), but these were prepared away. Then again, the same could have been true for the Solnhofen _Compsognathus_. Nevertheless, you (and Mike) make a valid point: the absence of *any* preserved integument in _Compsognathus_ makes the absence of feathers in this maniraptoriform equivocal.



There are even some specimens, where the primaries are so lightly preserved, that it was unclear they even were present (the Eichstat and/or Solnhofen specimen, and the Haarlem specimen), until advanced techniques found them in the limestone.

To reinforce your point, the bird specimens from the Messel show various degrees of preservation when it comes to feathers. These are neornithine taxa, so the presence of body contour feathers and tertials in the living birds is undisputed. However, of all the feathers (when present), those of the outer are almost always the best-preserved, and the rest of the plumage may be poorly preserved or undetectable. Hence, there is an apparent preservational bias favoring the primaries. This could be the product of a stronger attachment, in life and death; it is the primaries at the distal wing that require the greatest resistance to torsional forces during flight.





Tim

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