Re: dino mimicry

[Nicholas Roy Longrich <longrich@phoenix.Princeton.EDU>]

        The mimicricy idea I find a little hard to buy. The tail looks to 
be a pretty effective weapon: the first half bears large processes upon 
which to attach tail muscles, the second half looks to be a stiff shaft 
formed of interlocking tail vertebrae on which is mounted that enormous 
bone mass that looks for all the world like a club or mace. Tail weaponry 
seems to be very common among the dinosaurs- such as the whiplash tails 
of diplodocids, the club-tail of Shunosaurus, or the stegosaur 
tail-spikes. 
        Somehow, those massive, squat beasts with their plated armor and 
shoulder and neck spines don't look very much like an Iguanodon. The 
plating and a tail club would seem like protection enough against a 
tyrannosaur (if anything can really be protection against six tons of 
theropod) so they wouldn't really need to be mistaken for other 
dinosaurs. 
        Butterflies are the classic examples of mimics, with butterflies 
mimicking other poisonous butterflies. Birds have recently been found to 
do the same thing and mimic other, poisonous birds (no, really- some have 
poison-arrow frog poison); there are fish that look like seaweed, flowers 
that smell like carrion, flies that look like wasps and bees, spiders 
that look like venomous ants, bugs like twigs, weevils like bird 
droppings, mantids like flowers, etc. etc. etc.-  but for the most part, 
big animals don't seem to use much mimicricy (well, unless you count 
things like Japanese subs disguised as trawlers or German bombers 
disguised as airliners). Big animals generally seem to go for more 
expensive, but more dependable methods- armor, horns, speed, size and the 
like. Large animals may tend to evolve more conservative survival 
strategies, just a guess here...