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

Re: P.S. Oldest Neoceratopsian



In an earlier post Dan Varner asks about why I chose not to add feathers to
the tail of Liaoceratops. Sorry for the late reply Dan, it's been "one of
those"days.  I'm going to assume that your curiosity about this stems from
the psittacosaur specimen currently undescribed, that may or may not contain
evidence of integumentary structures.  I look forward to the inevitable
description and prefer to wait for the paper to confirm what the fossil
material reveals.

Concerning how I handled Liaoceratops, let me preface that by saying that I
am dedicated member of the feathered (theropod) dinosaurs camp.  I was an
instant convert from the moment in 1996 that Phil Currie and I had the good
fortune to be the first North Americans to see the first Sinosauropteryx,
less than a month after it had been excavated from Liaoning.  Of course, up
until that point, feathered dinosaurs had only been predicted by a few
individuals and especially championed by Greg Paul ( who, by the way, to my
mind, has over the years made many astute observations about the nature of
dinosaurs, through both his solid and convincing command of dinosaurian
anatomy and by way of his keen understanding of physiological biomechanics
and evolutionary function). I have, for the moment though, some reservations
regarding feathered ornithischians, but at the same time think it's possible
many groups outside of the theropoda may have been feathered, and like
everyone else, I expect to be mesmerized by the fossil evidence, if and when
it shows up.

However, for the present moment I will address the following couple of
points that impacted me most, in regards to Liaoceratops:

1.  remember that although the postcranial morphology reminds us visually of
a psittacosaur grade dinosaur, it still represents an early version of
neoceratopsian and is therefore something divergent from psittacosaurs
proper.  So any analogy or comparision concerning possible integumentary
structures may be moot.  Consider that when Ceratosaurus was discovered to
have a series of dermal scutes running down the midline of the spine, one
might have speculated that other kinds of ceratosaurs would have the same,
but fossil evidence shows that this is not the case.  I would think the same
might apply to feathers and other soft anatomical features.

2.  When I was in Beijing, in addition to looking at the Sinosauropteryx
specimen, we were shown numerous examples of Confusciousornis fossils, all
showing the identical type of preservation of integument AND several
Psittacosaurus skeletons in both lateral and "road kill" orientations from
the same beds, NONE OF WHICH showed any trace of feathery integument,  in
contrast to all of the other examples from the area, that we had the
opportunity to examine.

So, the upshot of it is, for the moment I chose a more conservative
representation ( I think Phil has instilled in me, a more cautious approach
in rendering newly described specimens that is a reflection of his own style
of methodical research ), until we have documented evidence to show
otherwise.  If and when this should occur, I will more than likely have to
modify my original version, to reflect any appropriate changes.  Sometimes I
like to have fun speculating on alternative visual possibilites regarding
dinosaur fashion and "flavor of the moment" when called for. But in my
experience, most paleontologists I have worked with have a particular
direction in mind when it comes to the artistic counterpart to their written
description and I usually try to match that as close as I can, based on the
information they convey to me ( and especially when it involves newly
described, first time visuals ).  So, no tail feathers on Liaoceratops, yet.
. .

Mike Skrepnick