RE: Sneak Peak at Yale Torosaurus Sculpture

[Ken.Carpenter@dmns.org]

The whole cheek debate is so fun! It shows the limitations of the
phyletic bracketing to explain novel structures in dinosaurs (like
Stegosaurus tail spikes, like cranial frills in ceratopsians, etc.).
Cheek plates are known for several ankylosaurs and the maxilla and
dentary surface textures look just like in ceratopsians and most other
ornithischians.  (wonder why only Greg Paul has pointed out that the
California condor has cheeks?)
Ken`

Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology/Chief Preparator
Department of Earth Sciences
Denver Museum of Nature & Science
2001 Colorado Blvd.
Denver, CO 80205
 
Phone: 303-370-6392
Fax: 303-331-6492
************************************************************
for PDFs of some of my publications, as well as information of the Cedar
Mountain Project: 
https://scientists.dmns.org/sites/kencarpenter/default.aspx

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf
Of Andrew A. Farke
Sent: Tuesday, September 27, 2005 3:10 PM
To: dinonaut@emerytelcom.net; dinosaur@usc.edu
Subject: RE: Sneak Peak at Yale Torosaurus Sculpture

Cool! A good discussion on something other than theropods!

Just a few comments to some of these points. . .

>     I am extremely disatisfied with this sculpture. There are many
glaring
> anatomical inaccuracies besides the cheek controversy. The two main
ones,
> besides the fact that the whole sculpture is misproportioned, is that
they
> based the skull on the old plaster, spit and hail Mary guesswork of
the
> original reconstructions of the 19th century. I understand that the
> Peabody
> has the original smashed flat elongated skull material, but hey,
complete
> skulls have been around for over seven years, and they don't look
anything
> like the original Marsh reconstructions.

Having spent a decent bit of time with both Yale specimens, they're not
really as bad as often stated. YPM 1830 actually has very little
crushing--the main problem is that the parietal and front of the snout
are
missing. I will agree that the original Marsh reconstructions of the
parietal and snout are pretty ugly--the rest of the skull is just fine.
Any
other differences are likely due to individual variation. YPM 1831 (the
T.
gladius holotype) is a little more crushed, and certainly covered in
more
plaster.

The skull for the sculpture was primarily based on YPM 1830, which is
the
better of the two skulls (the type for T. latus). Missing
portions--particularly the snout and parietal--were based on MOR 1122. I
made darned sure that the skull was correct! (in case anyone hasn't
guessed
yet, I was one of the consultants for this sculpture, particularly for
the
head)

I hear rumored that the big Torosaurus skull paper is due out next
summer. .


>     The second thing that bugs me, is that the two smallest frount
toes
> have
> nails. My understanding, is that no archeosaurs have nails on the last
two
> phalanges of the front feet. Please feel free to correct me if anyone
on
> the
> list knows something I don't, but I was severely reemed when I made
this
> same mistake years ago on one of my earlier pieces.

This is definitely true in modern crocs, if I recall correctly. What's
known
from sauropod footprints, etc.? I do recall a good hoof-like ungual on
all
digits of the ceratopsid manus, but then again this may mean very
little.

>     Ah, cheeks. I don't know if ceratopsians had cheeks either, but I
do
> know that armored dinosaurs did based on a skull at the ROM. I would
have
> to
> get the information from Jim Kirkland, but I have actually seen the
skull
> cast of a campanian ankylosaur with dermal armor plate directly over
it's
> jaw, and the otherside of it's jaw missing the armor plate. In other
words
> it had to have some kind of cheek, to support the dermal armor. 

That is very interesting; has it been published yet? I will certainly
accept
this as evidence of a "cheek" in ankylosaurs! Does anyone out there
who's
spent more time with ankylosaur skulls recall what the bone texture is
like
leading up to the tooth row? If there is a "vascularized" texture in
ankylosaurs, this would certainly counter my argument for ceratopsids.

>     Oh, and just in case I am coming off as sour grapes, I am set. I
have
> two bronze monument paleontological sculpture commissions in the
works. I
> just received the Dinosaur Discovery Site at Johnson Farm full sized
> Dilophosaurus  commission, and will be starting A full sized
Brontotherium
> bronze monument for the Badlands National Park, in March 2006.

COOL! I can't wait to see the latter, especially. . . Congrats!

Andy