RE: Triceratops epoccipitals

["Andrew A. Farke" <andyfarke@hotmail.com>]

> -----Original Message-----
> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of
> Nick
> Sent: Sunday, January 14, 2007 4:55 AM
> To: dinosaur@usc.edu
> Subject: Triceratops epoccipitals
> 
> I was just recently skimming over Goodwin and Horner's paper from last
> year, and I was curious after reading the section on ontogeny and
> epoccipitals. After spending a short time talking about it with
> Mickey, I thought posting a query to the DML might not be a bad idea.
> 
> Does anyone know of similar cases in nature where pointed triangular
> shaped edges change to low and rounded edges as the animal matures and
> why it might happen? I don't think "wear-and-tear" is necessarily the
> best explanation for this..

On a quick reread through their paper, I don't think that "wear-and-tear"
(or any other cause) is given as an explanation for the change in shape of
the epoccipitals in Triceratops. Instead, the implication is that it's due
entirely to bone modeling and remodeling (which is nearly ubiquitous in bony
animals).

As for pointy shapes changing to low and rounded shapes, I don't know of a
firm example off-hand. Maybe there would be an example in some of the dermal
bones or scutes of varanids or crocodilians? Epoccipitals are probably just
an ossified dermal bone, anyhow. Regardless, I don't think that *some* shape
change in the epoccipital is surprising by any means.

Andy