Re: Triceratops defence

[Ronald Orenstein <ornstn@home.com>]

I'm afraid this is going to make me sound like an awfully wet blanket, and
my apologies to the people on this list for whom the following is common
knowledge, but....

The best way, it seems to me, to answer a question like "how did
Triceratops defend its nest against T-rex" is to point out the problems
with the question itself.  I am not trying to put the questioner down here
- but anyone asking this sort of thing should stop for a moment and look
at, first, what they are assuming we already know, and, second, what they
are assuming we CAN know.

First of all, the question assumes that:
1. Triceratatops built nests
2.  Tyrannosaurus attacked these nests
3. Triceratops defended its nests.

Now, as far as I am aware, we do not know if ANY of these things are true.
As far as I am aware (and I stand to be corrected by the dinosaur
professionals on this list) we do not even know if Triceratops laid eggs
(though it is certainly reasonable to assume it did as live birth is
unknown for any archosaur), much less placed them in nests.  Of course
there is a great deal of controversy about what Tyrannosaurus ate, and to
what extent it was an active hunter at all, but I know of no evidence that
it ate eggs of any kind (though it may well have taken young dinosaurs when
it could - but again, we have no idea whether, even if Triceratops laid
eggs in nests, its young stayed in the nest after hatching.  In fact this
kind of hatchling behaviour is unknown in crocodiles and only found in some
groups of birds, so it might be quite reasonable to assume that the young
left the nest (if there was a nest) immediately on hatching - and, once
again, if they did we do not know if they were guarded by their parents or not.

In other words, when it comes to hard facts, we know very little about what
Triceratops (or any other dinosaur) actually did.  Artists can, of course,
use intelligent speculation to make informed guesses about how dinosaurs
looked and acted, but speculation is all it is - and sometimes I think that
speculation has been taken for knowledge by a lot of people.  Charles R.
Knight's famous painting of a duel between Tyrannosaurus and Triceratops
has certainly fixed in our minds the idea of these species as mortal
enemies - but it might be just as likely, or even more likely, that if the
two met Tyrannosaurus would give Triceratops a wide berth.  Predators do
not make a point of attacking full-grown, heavily-armoured animals that
could easily cause them severe injury; I know of no living predator that
will attack an adult black rhinoceros, for example, though lions will take
babies.  Mark Hallett (if I remember correctly) painted a herd of
Triceratops attacked by two or three T-rex, with the herd arranged in a
circle muskox-style, the adults protecting the young.  Again, a lot of
people seem to assume that Triceratops actually did this - but I do not
think there is any direct evidence for it.  Maybe they did - but maybe they
didn't.

This brings me to a more general point.  Not only do we not know these
things for sure - it may be pretty much impossible for us ever to find out.
 There is very little evidence of "fossilized behaviour".  There are a few
rare fossils, like the famous Protoceratops-Velociraptor duelling skeletons
and the brooding oviraptor, that do give us this sort of direct evidence,
and trackways can tell us something.  For those dinosaur eggs we can
identify, we can (if we are lucky) tell how they were laid.  I have
suggested here that the feather condition on Caudipteryx implies that these
animals must have used feather-maintenance behaviour like preening.  But by
and large the most fossils can tell us is what these animals had the
equipment to do - not whether they ever did it, or how often.  

Thus we know that Triceratops had fearsome horns - but we do not know how
it used them, or against what.  Were they used to fight off predators?  Or
in battles between rival males (or rival females)?  Or as show, to attract
a mate or secure a position in a dominance heirarchy without fighting?
Could they have had any function in finding food, perhaps by exposing the
pith of a tree?  Or were they for something else, something odd that no
living creature does?  We can speculate about all these things, but we do
not know.  And I might add that though a fossil could turn up showing a
Triceratops with its horns embedded in a Tyrannosaur's gut, or two
Triceratops locked horn-to-horn, 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?

To conclude - my point is not to discourage anyone from asking questions
(and I've asked plenty of them in my time - many of them not, in
retrospect, very intelligently put).  But I would hope that new dinosaur
fans on the list would appreciate not just the fascinations of
palaeontology, but its limits.  Surely part of the fun is that dinosaur
lives must always remain, to a great extent, a mystery.
--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
1825 Shady Creek Court                 
Mississauga, Ontario, Canada L5L 3W2          mailto:ornstn@home.com