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[davis@kahaku.go.jp: Q's arising from Archaeopteryx feathers]



Dear All
Thanks for the reprint requests, I'll send them out when I get the reprints
(luckily the journal gives away 300 free) unfortunately there are only
photocopies left of the feather taphonomy paper.  Unfortunately you are now
on my mailing list (via my computer address program) so you will have to
put up with the odd strange paper appearing in your mailboxes from time to
time.

There are some questions and queries that people sent me so I will send out
a communal message to save repitition - I apologise in advance if some of
these stray away from strictly dino themes.

Q.1 Funny, "Paul Davis" doesn't _sound_ Japanese!
That's cos I'm a brit who is in Japan on a postdoc looking at Mesozoic
birds from asia and also the evolution of the pacific seabird avifauna
(plus messing around with other verts when I get the chance!).

Q.2 I recall seeing in a recent issue of _American Museum Novitates_
concerning a feather in Cretaceous amber of New Jersey a mention of an
undescribed, purportedly Lower Cretaceous feather in amber from the
vicinity of Koji, Japan.  By chance do you happen to know anything of
this find?

Yes the specimen resides in a private museum which belongs to the company
which mines amber at this locality (the owner is Mr. Kazuhisha Sakai).  The
locality is Koji which is almost at the north-eastern tip of the main
Japanese Island of Honshu.  The amber deposits are Santonian in age and do
have various palaeontological inclusions.  Although I have never seen the
specimen in person I do have a photograph of it.  It appears to be a
fragment of a body contour feather and consists of 5 barbs (the bits that
come off the rachis -or quill) with associated barbules.

Q.3 I am sure that you are aware that Ellenberger (1972...or was it
'74?)  described some Late Triassic footprints (_Maisitisisauropus
palmipes_) as having tetradactyl, feathered manus prints.  However,
the photos in his monograph don't display these clearly at all, and
when I was investigating the matter several years ago, I was unable to
find a way to look at the actual prints myself.  Have you seen them?
I myself doubt the veracity of the claim (that is, if the impressions
are real, I'm dubious that they are feathers), but I'm curious as to
the opinions of others, as well.

I have to admit complete ignorance on this one I haven't seen or heard
any reference to these "Triassic feathers".  But it does seem doubtful
- after all the one thing about feathers - for whatever purpose they
evolved for (before anyone starts that argument again) is that they
don't work if the get wet/dirty or damaged.  Therefore "sticking them
in the mud" whilst walking is very unlikely.  An interesting aside is
the Aborigine dreamtime legend associated with the early cretaceous
trackway site of Broome, Western Australia.  In the sandstone that
outcrop on the foreshore are tridactyl theropod tracks (I can give the
refs and ichnogenera if people are interested).  These, according to
the legend, represent the footprints of a god who had a bird-like form
and appeared when he walked on land just after it had been created
from the sea in the dreamtime.  The legend also states that he dropped
his cloak of feathers on the ground and left feather impressions.
These feather impressions can also be seen in the sandstones.  They
are in fact fossilized fragments of cycads fronds which remarkably
resemble feathers.  I'm apologise to anyone who knows the story in
more detail but all in all it's not a bad bedtime story- eh!

Q.4 What is the smallest detail thus far seen in any fossil feather?
Feathers in amber preserve the most detail.  Feathers are comprised of
hydrous beta-keratin and because of the properties of amber (it acts as a
bactericide and is antiseptic yet allows gaseous percolation) the only
change is dehydration.  Therfore in theory (as nobody has allowed me to cut
up one of their precious specimens) it should be possible to see the
keratin ultrastructure under the SEM.
In more "normal" (whatever that is!) preservation it is easy to identify
the rachis (quill) the barbs that branch off from the rachis and the
barbules which branch off the barbs.  I have never been able to see the
hooks that occur on the tips of the barbules (these are the thing that
velcro or zip the feather together to give it a cohesive aerodynamic
membrane).

Q5.  And yet contour feathers are not preserved on Archy, correct?

Yes and no!  The Berlin specimen shows some traces in the neck region which
may well be body contour feathers but I have yet to convince myself.  The
others do not show any trace in the body regions.  This is interesting
because it may indicate that feathers first appeared on the wings and
spread to the body later.  If so this destroys the hypothesis of feathers
as evolving as insulators.  Also why do birds (on the whole - yes I know
there are exceptions) have unfeathered tarsometatarsi? Is this a genetic
condition from the unfeathered ancestor - most probably yes- but why did it
stay that way?

Q6.  EGGS?!?!?!?!?!
Yes, the Solnhofen Compsognathus has preserved (about 17 if memory serves
me right).
The reference is in dino eggs and babies book.  Until somebody comes up
with a better expanation for what the structures are then I am happy to go
along with the hypothesis.

Q7.  In physics and astronomy some researchers are posting pre-prints
of new papers on the WWW for review and comment purposes. The idea
being to get a better rnage of review comments eraly on.  On an
experimental basis I would be willing to place such pre-prints on my Web
server (at least for a time - how long would depend on disk space issues).
Perhaps the feather taphonomy paper would be a good starter for this
service?

Good idea but the copyright of the paper once published or accepted for
publication (which in essence is a pre-print) belongs to the publishing
organisation ie GSA, SVP etc. Therefore it could create legal headaches. 
The way around this is once you have submitted the paper (very important,
as I once had my research ripped off by not submitting first - ie nice guys
always come last approach to science) put out a message that you have a
paper and ask if anyone would like to read it and comment on it.  Then
these comments can be incorperated when the reviewers comments have to be
addressed.  Thanks anyway for the offer.

Q.8   [In reply to no pre archeo feathers]  _Praeornis sharovi_ is earlier,
but not everyone agrees it was a feather. A recent post to this list,
however, cites SCM data refuting the notion that it was a plant frond.
Yes, I think that was my posting in reply to Toni Lacasa-Ruiz.  Praeornis
sharovi is indeed upper Jurassic but (as with many of the central asian
material) the date is uncertain due to the lack of decent biostrat of the
deposits.  From examining the taphonomy of the specimen it is definetely a
feather and not plant (the mirco-texture of preservation in feathers is
distinct and can't be mistaken for plant).  However as an aside the
"feather" specimens of Diatryma are most probably decay palm leaf fronds! 
So bang goes all those reconstructions of an Ostrich style plumage for
Diatryma.

I am always on the scrounge for any papers that people have written on any
subject of VP as it helps me to prepare half decent VP lectures.  So any
contributions to the PG reprint collection are gladly received.

Thanks for your indulgence

Paul

(some call me PG, some call me PJ I don't mind what people call me as long
as they don't call me late for dinner) - with apologies to Tom (TIM) Holtz

-----------------------------------------------
Dr. Paul G. Davis
Division of Vertebrate Palaeontology, National Science Museum, 3-23-1
Hyakunin-cho, Shinjuku-ku, Tokyo 169, Japan.
 
e-mail davis@kahaku.go.jp
Tel + 81 3 3364 2311
Fax. + 81 3 3364 7104
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