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Re: Common ceratopsian horn ailments

Larry Dunn wrote:
> What, if anything, does the fossil record tell us about common
> ailments of ceratopsian (or ceratopian, if you prefer) horns?
> Breakage, problematic rehealings (if this happened), rot, possible
> problems due to prior malnutrition, whatever.
> If there is a decent amount of material, if it genus or species
> specific or common to all ceratopsians?
> Most importantly, how would it manifest itself physically?  For
> instance, how would part of a horn have broken off? Please be specific
> if you can so that I get a decent idea of what I'd be looking at if I
> were standing a few feet from the head of the animal.
Unfortunatly Darren Tanke isn't on this list anymore, but I'll answer
this the best I can. Severial ceratopians do show broken and rehealed
horns. I've seen some Triceratops that are like this (BHI sells a
specimen). The best bonebed that shows this is the Pipestone Creek
Pachyrhinosaurus (new sp, if not genus) has severial pathologic skulls.
The horns on the parital, back of the skull, are distorted, broken,
rehealed, etc. I found one when I was at the site. We had thought it
belonged to a juvenile ilium. There was a huge block covering it and we
had to stop to back up to go to the Mesozoic Ecosystems Symposium at the
Tyrrell (The next one is going to be in Argentina, which I'd like to
attend). Darren later wrote to me and said, you'll never believe what
you found, and he didn't tell me untill several letters later. It was
the complete back of the frill, but the one side was almost completely
broken off and rehealed. There is another specimen that has a dinner
plate sized hole infront of the right(?) orbit. What excatly was going
on with this assemblage I don't know.

A year later at DDP (Dinosaur Provincal Park), Darren, Hans Larson and I
ware prospecting about the badlands and a small concrete like mound had
a centrosaurus back of the frill in it. There was a small squamosal near
by in softer dirt. Darren and Has bent to work on the concrete mound,
while I (luckly) dug out the squamosal. It turned out to be of an adult,
the bottom part of the squamosal was missing, but you can tell it was an
adult and was not broken off during burial. Darren has me now looking at
mounted specimens for pathologies. Last year at the AMNH I counted about
a dozen broken ribs on the Allosaurus mount, broken and fused caudal
vertebrae, and a growth on the bottom of the left scapula. There are
other specimens that have pathologies there also.

Just as another side note, that brooding Oviraptor has a broken and
rehealed ulna.