I read the other day that a Dinosaur with a long neck like a Brontosaurous
would not have a stong enougth heart to pump the blood to its head, in to
days strong gravity. It would in fact only last more then a few
seconds/min according to this article and then die due to lack of blood
flow. They also said that a very large whale is crushed by its own weight
if on land today thus proving the theory that the earths gravity is eight
times stronger today then at that time. Is this true, sounds very
diferent to me then what I'm used to hearing.
Well, it probably is different than what you're used to
I would prefer if you had given the reference. Not everything you read is
true; this itself is a truth that many people have trouble learning. I
think I was sent this question because I am already on record on this
topic. I personally would just have referred you to my
previous answer... but here goes.
One thing I would change from my previous answer: there are enough
really, really big bones around that we can no
longer say with confidence that "no dinosaur was as big as the modern
blue whale." But they were still land animals, and fully capable of
holding their own against gravity!
- There is no reason to think the Earth's gravity is any
different today than it was in the past. None. Nada. Zilch.
- Whales are not land animals. Normally water
buoys up their mass, and they don't need to have gravity-resisting muscles.
So when they are stranded on land, they suffocate because they don't have
the muscles to breathe against gravity. This has nothing to do with
size. Very small whales (dolphins and porpoises, which mass a lot less
than land animals like elephants or hippopotomi or rhinoceri) can't live
long out of water either, for the same reason as the giant whales.
- Dinosaurs were land animals, with the
skeletal (and muscular) framework to deal with the pull of gravity. They
could breathe on land, they could move on land, they could and did thrive
on land. This is not just conjecture along the lines of "they lived on
land, they must have been able to breathe!" The muscle attachment
scars on dinosaur bones give us a good idea of the muscular power of the
beasts. And large dinosaurs were powerful indeed!
- Sauropods (the Brontosaurus types) had the same sort of
blood-to-brain problem as the modern giraffe, which gets blood to its brain
quite well, thank you very much. Why do you think sauropods had such small
heads? Their heads were as large as they could be, given the
limitations of forcing blood up that long, long neck. Anyhow, how does
your source know that no sauropod could have had a heart adequate to
the task of pumping blood to its head?
Last I saw (Walking with
Dinosaurs, the companion volume to the BBC-TV series) it is thought
that sauropods grew so large because they had to process coarse vegetation
entirely in their guts -- no dinosaur until Iguanodon, quite a while later,
was able to chew. Because food processing was entirely stomachic and
intestinal, the sauropods needed long guts, and large bodies to hold them.
Long necks may possibly be
- to reach higher vegetation than other herbivores or, more likely (?),
- to allow maximum grazing for minimum actual bodily movement.
- Robert Bakker (not the least controversial of dinosaur
paleontologists) believes that dinosaurs set and explored the size limits
for land-living animals. See his book The Dinosaur
I'm sorry if I got a bit snippy, but the piece of misinformation you were
fed is not only a canard (French for "duck") but a mighty lame