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

Re: Missing link feather fossils



--- "Richard W. Travsky" <rtravsky@uwyo.edu> schrieb:

> 
> 
> On Mon, 25 Feb 2008, Dann Pigdon wrote:
> 
> > Richard W. Travsky writes: 
> >> Hmmm. Any chance some hint of color was
> preserved? The picture on that 
> >> link is b/w.
> >
> > I wonder if amber can preserve original colours at
> all, or whether chemical 
> > processes in the resin might alter the colouration
> (but not necessarily the 
> > patterning). A quick Google search resulted in
> comments like colour 'pattern' 
> > or iridescence being preserved, but most of the
> pictures of amber-encased 
> > fossils tend to show little more than shades of
> brown.
> 
> Patterning is useful info too.

One could (in good specimens, say Messel, Fossil Lake
or Liaoning) possibly distinguish melanin vs
lipochrome vs structural colors. The former two would
need heavy-duty chemical analysis tough.

I don't know if anything noteworthy would remain of
structural colors, and even if, if it is recognizably
distinct.

That being said, I also don't know what got the BBC to
make their _Iberomesornis_ bright blue. Of all
possibilities, this is probably the second-worst
(after all-white). It's not impossible (you need a
pennaceous feather as minimum requirement, otherwise
you can't arrange the keratin properly), but in
Neornithes at least, structural colors evolved
independently in some Galliformes and some
Anseriformes, where they were limited to display
plumage (Dito hummingbirds, parrots, passerines etc).
It is more parsimonious to assume that there was no
large areas of blue plumage in *any* Mesozoic animal.
Green maybe, as it might have been cryptic (*Maybe*.
Color vision in bird predators of the Mesozoic is not
well deductible I guess, but UV vision may a) have
been present and b) might make certain greens actually
stand out from a foilage background). Blue signal
elements, certainly possible. But even among living
birds, large areas of bright blue color are extremely
rare.


Regards,

Eike


      Lesen Sie Ihre E-Mails jetzt einfach von unterwegs.
www.yahoo.de/go