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RE: Modern feathers on a non-avian dinosaur - today's Nature

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
Sent: Wednesday, March 06, 2002 2:15 PM
To: dinosaur@usc.edu
Subject: RE: Modern feathers on a non-avian dinosaur - today's Nature

Here's where to get CNN's version of it:


One weird thing in the article: "It is the third dromaeosaur EVER
discovered." (emphasis mine).  This doesn't quite seem right to me :-).<<
No, the article says it was the third to be found, not the third dromaeosaur
found. It is the third of this dromaeosaur 'species' to be found in the
Liaoning. I'm checking right now, but last year when I mentioned there was a
new dromaeosaur with feathers on the list and some of you took offense to
it. Well, I'm checking with some people, but this may be the same specimen.
If so, the s(*t may hit the fan with some people about it and I'm not
talking about whether or not its real. I have seen photos of a second
specimen and may have seen a third at the Tucson show.

>>Also, they mention _Archeoraptor_ and say "Authenticity was called into
question and critics claimed that only one side of the slab had been
studied. Critics also said that pieces of the fossil could have been cobbled
together and that the specimen included more than one animal. "

This seems to me to be slightly one-sided, and lacking information (i.e. the
fact that nearly ALL paleontologists that have studied the specimen agree
that it is 2 separate animals [I think I remember 1 holdout]).<<

Hmm, I can't comment on this quite yet.

Tracy L. Ford
P. O. Box 1171
Poway Ca  92074

Allan Edels

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
Williams, Tim
Sent: Wednesday, March 06, 2002 2:56 PM
To: 'dinosaur@usc.edu'
Subject: Modern feathers on a non-avian dinosaur - today's Nature

Actually, it's tomorrow's _Nature_, since it's a British journal.  Anyway,
the latest issue of _Nature_ features this article, which will put a smile
on a few faces.  (I had advanced warning - thanks to the kind soul who gave
me the heads-up.)

(2002).  Palaeontology: 'Modern' feathers on a non-avian dinosaur.  Nature
416: 36-37.

This is a 'Brief Communication' that (appropriately enough) briefly
describes a new theropod specimen, BPM 1 3-13, from the Jiufotang Formation
in Liaoning Province, China.  This is the specimen referred to by Prum
(2002) in his recent _Auk_ article.  The dromaeosaur (which is not assigned
to a specific genus or species by Norell et al.) comprises a nearly complete
skeleton measuring around 95cm long.  The tail is proportionately longer
than in NGMC 91 (which the authors say "can probably be referred to
_Sinornithosaurus_") and _Microraptor_.  BPM 1 3-13 shows several advanced
osteological features (stiffened dromie-like tail; "sickle-claw";
hourglass-shaped sternum composed of two sternal plates and with sockets for
the sternal ribs; semilunate carpal that caps mc's 1 and 2), but lacks
avialan features such as unserrated teeth, short tail, and reversed hallux.

Integumentary fibres are distributed over the entire body of BPM 1 3-13.
However, those associated with the back of the forelimbs and hindlimbs and
end of the tail are the focus of this paper: these are clearly in possession
of a rachis and barbs, conforming to the 'modern' (pinnate) morphology,
hitherto described for _Caudipteryx_, _Protarchaeopteryx_ and
incontrovertible birds.  Interestingly, the tail feathers produce a longer
plume than _Caudipteryx_ or _Archaeopteryx_.  All pinnate feathers described
for BPM 1 3-13 have symmetrical vanes.

However, Prum (2002) mentioned that the specimen has barbules, and I see no
mention of barbules in the paper.  If barbules are established to be present
(either by direct observation or inferred from the arrangement of the barbs)
then the rachis-and-barbed feathers of BPM 1 3-13 would qualify as
'bipinnate'.  I would guess we'll have to wait for the complete description
for the resolution of that issue.

I find the development of pinnate feathers along the forelimbs AND the
hindlimbs extremely interesting.  It brings to mind William Beebe's
hypothetical proavian ("Tetrapteryx"), as well as the analogy of parachuting
and gliding primates.  The latter are thought to use the long, shaggy hair
along the arms and legs as a gliding surface in aerial locomotion.  Of
course, these critters are all arboreal...



Timothy J. Williams

USDA-ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163