Re: TOROSAURUS/TRICERATOPS FRILLS

["Allan Edels" <edels@email.msn.com>]

Andy, et al:

    I have to agree with your assessment of the _Torosaurus latus_ skull
here at ANSP.  Before they rebuilt the exhibit [1998], the skull was lower
down and very accessible, placed to the left-side of the _T. rex specimen
(based on the _T. rex's_ point of view).  You used to be able to see more of
the back than you can now.

    However, I may be wrong - as you indicated there is a lot of stuff stuck
on the back.  You might have some better information available from Ken
Carpenter (who is on this mailing list).  Ken led team who put together the
previous version of the exhibit in 1986 (which included the _T. rex_, the
_Torosaurus_ skull, the _Chasmosaurus_ cast, the _Deinonychus_ cast, the
_Tenotosaurus_ specimen and casts, the _Avaceratops_, and the
_Corythosaurus_).  As I recall, a detailed cast of the _Torosaurus_skull was
made, and a copy was sent off to one or more museums that traded with the
Academy, supplying several specimens.  Ken spent a long time working with
the skull (I don't know if he did the work, or whether he assigned others to
work directly on it.

    In any event, he might have additional information, and may have
pictures taken from then.

        Allan Edels

-----Original Message-----
From: Andy Farke <andyfarke@hotmail.com>
To: dinosaur@usc.edu <dinosaur@usc.edu>; qilongia@yahoo.com
<qilongia@yahoo.com>; jconrad@lib.drury.edu <jconrad@lib.drury.edu>;
franczak@ntplx.net <franczak@ntplx.net>
Date: Saturday, September 12, 1998 11:47 AM
Subject: RE: TOROSAURUS/TRICERATOPS FRILLS


>Here's a reply to several messages, all lumped together here.
>
><I was wondering if there is any possibility of _Triceratops_,
>_Brachyceratops_, and _Avaceratops_ being related based on the solid
>frill. I realize that the remains are fairly poor for the latter two.>
>
>Brachyceratops and Avaceratops are closely related, but neither of those
>are closely related to Triceratops. Brachyceratops and Avaceratops are
>members of the Centrosaurinae, the more primitive subfamily of the
>Ceratopsidae. There is some debate over whether or not the frill of
>Avaceratops was solid, but I have seen the type specimen for it, and if
>there were fenestrae they were dang small.
>
>My opinion, backed up by many characters, is that Triceratops and
>Avaceratops independently lost their parietal fenestrae. Based on other
>characters in the skull, it seems that Triceratops is more closely
>related to Chasmosaurus and Torosaurus than others. (see below).
>
>>There is a distinct similarity between *Triceratops* and
>*Torosaurus*, mostly the general appearance of the face, horns, nasal
>fossa or whatever it's called, and frill, with Toro having small
>fenestrae and a very smooth margin, kinda like some specimens of
>Trike; in fact, the most similarity I can see is between the heads of
>*Diceratops/Triceratops hatcheri* and *Torosaurus latus*. Andy Farke
>may prove me wrong, as he seems to me the most ardent worker on Toro I
>can find.
>
>Nope, I won't prove you wrong, Jaime. Torosaurus and Triceratops both
>show trends towards closure of the postfrontal fossa, loss of parietal
>fenestrae and other things. There's quite a few other characters,
>published by Tom Lehman back in 1996, that back this up.
>
>>They are basal Centrosaurinae, and Toro/Trike may be
>advanced Chasmosaurinae. Some skulls of Trike are very similar to
>centrosaurines, like *T. "obtusus"* and *T. "serratus"*, so they may
>be basal, and the semi-solid (very thin on both trikes and Brachy and
>Ada) mid parietals are quitre similar.
>
>I only partly agree here. "T. obtusus" and "T. serratus" are probably
>not basal, but about as advanced as you could get. I agree that the
>parietals are similar, but they were acquired independently. My
>examination of the specimens shows that Avaceratops and Triceratops have
>few if any other similarities. The shape of the squamosal is
>characteristically centrosaurine in Avaceratops, and Triceratops has a
>chasmosaurine, although short, squamosal (I'll add here that there is
>some variation in that, too. I'm doing research on it at present).
>
>>I have seen photographs of a recently-excavated specimen of
>_Torosaurus_ from ?Montana that has obvious epoccipitals, so despite the
>way this ceratopian has been reconstructed and restored over the years,
>it's apparent that it did indeed have them along the edge of the frill.
>
>It's been known since the 1940's that Torosaurus had epoccipitals.
>Gilmore, in his paper on Arrhinoceratops? (now Torosaurus) utahensis
>described about a dozen or so epoccipitals that were found with
>Torosaurus specimens in Utah. The specimen you mention from Montana is
>on display at the Milwaukee Public Museum, I believe. That specimen, as
>I will argue in my upcoming DinoFest paper, also represents T.
>utahensis. So, right now the best evidence is that T. utahensis had
>epoccipitals and T. latus didn't. BUT (and there is always an exception
>to every rule). . .
>
>I had a chance to examine the T. latus female specimen on display at the
>Academy of Natural Sciences in Philadelphia. That animal was advanced in
>age when it died, so most everything was fused together. Along the edge
>of the squamosal, there are what appears to be 3 fused-on epoccipitals.
>(I took pictures) They seem to be long and low, and may not have
>disrupted the smooth border of the frill very much. However, due to the
>heavy amount of varnish and junk that's been applied over the years,
>it's difficult to tell if these are actual epoccipitals or if the bone
>is just worn here. I was able to see them only after crawling up on the
>mount and looking closely. Does anyone else have an opinion?
>
>>As for _Triceratops_, I would guess that most (if not all) of the
>specimens with "smooth-margined frills" are casts of the mount at the
>AMNH; the frill on that skull is *very* heavily reconstructed, and
>considering the evidence from other _Triceratops_ skulls, is undoubtedly
>wrong.
>
>You're right here, Brian. Some of these smooth-margined Triceratops may
>be the result of the epoccipitals falling off. They tend to do that
>except in the oldest individuals. One juvenile Triceratops squamosal
>that I've seen had epoccipitals with it, but they had fallen off after
>death. The frill margin is very smooth otherwise, so that if the
>epoccipitals weren't associated with you never would have guessed that
>the little guy had them.
>
>I'd be glad to here of anyone else's thoughts or comments on this!
>
>Thanks,
>Andy Farke
>
>The Torosaurus Home Page
>http://www.geocities.com/CapeCanaveral/Hangar/3404
>andyfarke@hotmail.com
>
>
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