Re: bipedal lunges

[Dann Pigdon <dannj@alphalink.com.au>]

Toby White wrote:
> 
> After mulling over the comments of John Calvin and Bill, I concede.  What
> I'm struggling with is the physical and tactical difficulty of a "charge" by
> a ceratopsian combined with the highly variable geometry of the offensive
> armament.  For actual defense against predators, how do we get the horns, or
> even the beak, into play while still -- literally -- allowing the
> ceratopsian to cover his ass?  That's a big, vulnerable target, no matter
> how well-protected the head.  Either the backside is never exposed (e.g. by
> stolid group defense) or there's some way for the beast to turn rapidly.  I
> was trying to come up with a behavior which would allow some of both.  What
> are the other alternatives?
> 
>   --Toby White

        This is the same dilemma faced by Cape Buffalos if they
are attacked by lions (which isn't very often). As a group the
buffalos can intimidate lions enough to prevent being hunted,
but if a single buffalo is separated from the herd then the lions
may have a chance. The buffalo is then faced with a dilemma: to
try to outrun the lions, while exposing its vulnerable backside to
them; or to stand still and confront them with its pointy end. Often
this will result in a stalemate, with either the lions winning through
force of numbers, or the rest of the herd coming to the buffalo's
aid and driving the lions off.
        Cape Buffalos are enormous creatures, yet they seem to be able
to turn fairly quickly to put their horns to good use. Given that
a triceratops, or most neoceratopsians for that matter, seem to have
had more impressive (but more functional?) pointy bits than a
buffalo I would expect they would also possess the ability to put
them to effective use, both as a group and as an individual separated
from the group. 
        There is of course the possibility that those heads were mostly
for show. Most species of oryx have such long horns that I doubt
the pointy ends are of much use as a predator defence. The peacock also
has a tail that, although useful in attracting a mate, is otherwise
a hinderance when it comes to escaping predators. Yet these species
have other means of escape (running and flying in these examples).
Ceratopsians seem to have concentrated most of their armourment
towards the front end of the beast, so those heads probably had
a degree of defensive functionality as well, which would have required
the ability to put them to efficient use. Unless it was all bluff.
-- 
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        Dann Pigdon
        Melbourne, Australia

        Dinosaur Reconstructions:
        http://www.geocities.com/capecanaveral/4459/
        Australian Dinosaurs:
        http://www.alphalink.com.au/~dannj
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