[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Archaeopteryx had black feathers



> I believe the holotype was
> re-assigned due to the fact that anchoring
> a name on an isolated feather is a recipe for a numen
> dubium, so it is
> a valid issue. However, as there are no other generally
> recognized
> aviremigian species in the Solnhoffen deposits (we've got 11
> specimens
> of A. lithographica and nothing else) it's a reasonable
> guess that the
> feather belongs to A. lithographica.

Yeah, technically if should be "cf. _A. lithographica_", or "referred _A. 
lithographica_ (e.g. in a study like this).

 
> Would be interesting to see someone examine the melanosomes
> from a
> skeletal specimen and verify or falsify the presence of
> black coverts
> (of course there could be sexual dimorphism, subspecific
> variation,
> ontogenetic variation, seasonal variation, etc. to consider,
> but a
> positive match would be something).

The place of a hypothetical _A. lithographica_ shedding that feather in the 
ontogenetic series can, IIRC, be fairly certainly determined (presuming that 
"most if not all"[*] specimens are from a single species, as it presently looks 
like).

* including _"Jurapteryx"_ (fledgling) and _"Wellnhoferia"_ (subadult), but 
excluding "non-_lithographica_" at leisure

Don't have the literature at hand, but IIRC the size/proportion differences 
between the feather and London/Berlin (which are "average", i.e. young 
immatures) are detailed in several studies.

Black in the flight feathers is about the most uncontroversial plumage detail 
in any theropod that is at least passively volant. Absence of this trait (whose 
function is well determined) is almost nonexistent among crown Aves, even in 
otherwise extreme cases: 
http://upload.wikimedia.org/wikipedia/commons/d/d6/Leucopsar_rothschildi_-Brookfield_Zoo%2C_Chicago%2C_USA-8a_(1).jpg

To find abundant (eu)melanosomes in a flight feather is the null hypothesis. 
Anywhere else, anything goes.


Eike