Re: Triceratops defence

[John Bois <jbois@umd5.umd.edu>]

On Sun, 13 Jun 1999, Ronald Orenstein wrote:

> 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.

The best analogies we have, ratites, suggest that parental guarding was
essential.  Indeed, any avian non-flying hatchling is at the mercy of
numerous predators.  Without a mechanism for escaping predation (eg.,
protection by parents, flight, running as in large placental
neonates--much further along developmentally than any hatchling!)
triceratops babies would never be recruited into older age classes.  This
probably boils down to parent/offspring size ratio.  The bigger a dinosaur
was, the smaller was their baby in relation to the parent, thereby
qualifying them as excellent prey!

> 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.

But there _is_ a difference between various kinds of speculation.  And it
all depends upon the quality of evidence that is used.  At one extreme,
arguments that dinosaurs had red blood are very strong and, though we
cannot verify it, we would be foolish contradicting someone who claimed it
as (almost) fact.  At the other extreme, cooperative hunting tactics,
while this is certainly an intelligent hypothesis, is further from fact
than red blood.  I maintain that nesting strategies are more solid than
the latter, less solid than the former.  My point, though is that we _can_
apply our skills of reason to hypotheses for which there is only
circumstantial evidence, in order to get closer (at least) to the truth.

> 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.

Right, the specifics of these behaviors must remain a mystery.  However,
it is highly likely, assuming they laid eggs, that triceratops laid their
eggs in a nest and defended it vigorously.  Thsi also assumes they
couldn't hide very well over the entire incubation period (a reasonable
assumption, I think).

> 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.

True.  Geez, we can't even figure out why a giraffe has a long neck!