Re: Triceratops defence, w/added stuff

[Andy Farke <andyfarke@hotmail.com>]

> [Ronald Orenstein said. . .] Again, a lot of people seem to assume that 
> Triceratops actually did this [herding] - but I do not think there is any 
> direct evidence for it.  Maybe they did - but maybe they didn't.

Yes, yes, yes! As Roger Stephenson also pointed out, there is little 
evidence for herd behavior. Roger said he doesn't know of any bone beds for 
Triceratops, and neither do I. In fact, I don't know (off-hand) of any 
places where more than two Triceratops have been found co-mingled. Of 
course, there's also the chance of depositional biases, etc. (but what about 
all those Edmontosaurus bone beds also in the Hell Creek, and there's alot 
of 'em?).

To me, it seems that all of the "evidence" for Triceratops herding is 
non-existant, based only on the "extant phylogenetic bracket" approach. Bone 
beds are known for Chasmosaurus, Torosaurus, Pachyrhinosaurus, Einiosaurus, 
etc., implying *but not proving* herding. No bonebeds are known for 
Triceratops (of course, that doesn't mean they don't exist). However, I 
don't believe Triceratops was a terribly enthusiastic herder. As Mom would 
say, "Just because everyone else is doing it. . ."

And, herding may only have been seasonal, for mating, migration, etc. I 
should point out here that evidence for ceratopsian migration is 
circumstantial at best, based on Pachyrhinosaurus material found in Alaska 
and Alberta. Whether these are even the same species of pachyrhinosaur is 
questionable. Has anything been published yet on these?

> I do not see how we could ever find a fossil that would demonstrate if the 
> horns were used simply to show off. What would such a fossil look like?

Tom Lehman described a nice Chasmosaurus mariscalensis bonebed back in 1989 
(with a sequel in 1990), with apparent sexual dimorphism. There appear to be 
differences between the orbital horns of male and female C. mariscalensis, 
suggesting they may have had some role in "showing off." However, evidence 
for sexual dimorphism in other ceratopsids is slim or non-existant (just 
because there's not a good sample or study done).

This does not exclude the possibility of the horns being used for other 
purposes (defense, food procurement, etc.). There is evidence for these also 
(which I won't get into now).

> . . .a fossil could turn up showing a Triceratops with its horns embedded 
> in a Tyrannosaur's gut

I would pay money to see that. The coolest ceratopsid painting ever was the 
one in Pete Dodson's ceratopsian book showing a Triceratops walking away 
from a bleeding, dying T. rex (captioned something like "What happens when 
T. rex and Triceratops fight").

In summary, there is little hard evidence for a lot of the supposed behavior 
in ceratopsians (or other dinosaurs). The best way to counter this is study 
of the specimens. I think the evidence is out there (for or against)--it 
just needs to be collected and analyzed.

Andy Farke


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