>Myhrvold and Currie ... agreed with the paleontologists who now reject the idea that the sauropods regularly used their tails defensively. The animals would probably have sustained as much injury to their tails as they inflicted on attackers.
Some recent reptiles like
crocodiles, iguanas and monitor lizards use their tails as a defense - though
the speed performed is not supersonic.
Let me ask those who reject the idea of sauropods using their tails
defensively ("regularly"- what does it mean - like once or twice a
day?), how did Shunosaurus and ankylosaurs got their tail clubs in the first
place? They didn't grow them overnight. Their clubs evolved from using the tails
for defense (regularly or not). Anyway, I am sure they were not so well equipped
at the beginning of their evolutionary path and that their tails were fragile
looking, too. However, some strange things occur ( strange to me, since I am not a
physicist nor a marshal arts expert) when using a high speed for a blow. We all
know the hands of a karate or kung-fu fighters are in fact fragile, but they
still manage breaking bricks. A fragile straw, carried with a tornado can pierce
a wood. A fragile whip-tail of a sauropod could have acted in the similar way
(forget the tornado). Anyway, it looks like a whip - why should a whip-like tail
evolve if not for being used as a whip? At the end, please, allow me a digression or two: Though, we can hardly
except these facts - some bacteria live in a boiling water, some other organisms
in ice, some in acid. Some insects are "so heavy" they shouldn't fly,
and yet they still do. We could find countless examples like this. Mother nature
is still smarter than science. There are some ways of solving the problems in
nature the official science (at the present stage of development) presumes that
can't be solved. If some sauropods possessed a whip-like tails, I believe these
were not for chasing off flies - they evolved with an obvious purpose - for
defense against fierce predators (and some of them were much bigger than lions
and tigers) and for territorial disputes with the members of the same species
(intraspecific fights). Imagine, that the elephants were extinct long before
humans and that paleontologists discover a mummy with a well preserved trunk.
First, we'd all be amazed, then intrigued with a purpose of such an organ. And I
bet you, many conservative scientists would conclude the bizarre trunk was to
weak or fragile for any other purpose than decorative, and that it hung from the
animal's head lifelessly dragging on the ground.( Some people would probably
conclude the creatures went extinct because of their overgrown noses).
Where does all that ideas come from - that herbivorous animals don't use
their horns, teeth and other weapons for other than intraspecific fights?
Obviously, the promoters of the idea were never being chased by an angry ram or
goat.>Nathan Myhrvold wrote: >Finally, it is not at all obvious why sauropods would need a specific
defense mechanism. They are HUGE. Elephants and rhinos do not have
any "defense" mechanisms per se. Rhino horns and elephant tusk
are used almost exclusively for display, and intraspecific fights. Don t you people watch natural history documentaries? The only reason
elephants and rhinos don't use their weapons for defense is because they don't
need to - lions (or tigers) don't even dare coming near them. Yes, sauropods
were huge, but so were some theropods. Take the mass ratio of elephant/lion =
5,000/250 kg = 20 compared to say Apatosaurus/Epanterias = 25,000/5,000 kg =
5.
Nevertheless, I am conservative on the "supersonic cracks", sauropods
might have made. Even if they've grown a dead keratinous tissue on the very end
of their tails - that would wear out after a "regular use" very fast.
I remember, playing with a piece of rope making cracking sounds, when I was a
kid. The end of the rope "blossomed" after a couple of cracks. Regular
use of a whip tail for supersonic crack would require an extremely high rate of
regeneration of keratinous skin, I suspect. But, I can't reject the idea
itself.
veselinka.stanisavac@siol.net
Beri's Dinosaur World
http://www.geocities.com/CapeCanaveral/Lab/1638/index.html
Dinosaur Books
http://www2.siol.net/ext/zza/index.html