Re: Triceratops defence, w/added stuff

[Stanley Friesen <sarima@ix.netcom.com>]

At 08:51 AM 6/14/99 -0500, Andy Farke wrote:
>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.  ...

In my opinion, the phylogenetic bracket is not really useful for herding,
since among extant herbivores there is considerable difference in herding
behavior between closely related forms.

Now, I would be surprised if _Triceratops_ didn't remain in at least small
groups, at least part of the year.  But that is a pretty weak statement.
>
>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....

Also, given the situation at the time, east-west migration would have been
more likely.      A change in altitude of a few thousand feet is equivalent
to many hundreds of miles in the north-south direction.  Denver is
mid-temperate, a mere 20 or so miles outside of Denver is a boreal-type
forest of spruce and fir, and a handful of miles beyond *that* is a tundra.
 Since the Rockies had already started to form by the Late Cretaceous, even
though they were less high than now, this west would have been the shortest
way "north".

--------------
May the peace of God be with you.         sarima@ix.netcom.com