Protofeathers vs feathers (was Re: Buffetaut about the spikey psittacosaur)

["Tim Williams" <tijawi@hotmail.com>]

Tom Holtz wrote:

> The latest Nature has a short letter by Eric Buffetaut (p. 147) about >the 
> infamous "feathered
>  Psittacosaurus specimen.  [snip]  His conclusion was that the
> integumentary structures were real, and that they were apparently different
> from feathers & protofeathers in detail.

This reminds me of a question I've had for a while.  What precisely is the 
difference between a "feather" and a "protofeather".  Is it phylogenetic: 
birds have feathers, non-avian theropods have protofeathers?  Or is it 
structural: if it looks like a feather, it is a feather.  In other words, if 
the integumental appendage of a putative non-avian theropod resembles the 
contour feather or plumule of an undoubted bird (living or fossil) then it's 
a true feather; if the integumental appendage lacks a central shaft (such as 
the "sprays" or "tufts" described for some Yixian theropods), then it's a 
protofeather.

> From my reading of the literature, and by quizzing paleontologists, it seems 
the line between "feather" and "protofeather" is very blurred.  And, like 
most things, it seems to be a matter of opinion.

> For reasons unknown the plan failed: no joint study will be done,
> and the present whereabouts of the specimen are unknown to Buffetaut.

Sheeesh!!!  Another specimen lost to science.  That really makes my blood 
boil.




Tim

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