Dinosaurs and the reduced felt effect of gravity

If Saurapods were operating at lower gravity why is it that their bones are structually designed to take the operating loads predicted at current gravitational levels? Why is it that their bones have air gaps - a weight reduction measure similar to modern birds? Why is it that their pelvis consist of five fused veterbra with a cleft structure apparently modified to support vast loads and hold a huge tendon? Why do they need gastralia if not to support their massive weight?[This message has been edited by Mr Jack, 04-19-2004]

Any chance of a link to a peer-reviewed work that came to that conclusion? Or anything in respectable scientific literature? Or even the maths itself?

quote:

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How do we weigh dinosaurs?

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There is a regular relationship between the weight of an animal and the cross-sectional
area of its legs.!

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This relationship has been developed for modern animals, using animals that range in size
from shrews to elephants.

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In general:
Mass is proportional to Leg area (to the power) 2.75

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Typical weights derived using this method in metric tons (=1000 kilograms):
Big Theropods (e.g., Allosaurus, Tyrannosaurus): 2 - 7 tons
Sauropods (e.g., Diplodocus, Apatosaurus, etc.): 6 - 50 tons, biggest ~180 tons
Ornithopods (e.g., Iguanodon): ~5 tons
Stegosaurs:! 2 - 3 tons
Big Ceratopsians (e.g., Triceratops): 4 - 6 tons

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(edited for formatting)From here: http://faculty.evansville.edu/...3/PDFs/17_Dino_Paleobio.pdfNow, these weights were extrapolated from the leg area of the Sauropods - why would they have these leg areas if they were not so heavy?

The idea that you can simply scale up a human weightlifter is non-sensical. Humans simply do not work in a mechanically comparible way to a sauropdod. Note that it is not actual muscle power that is the issue but rather the way that that muscle can be utilised.If your form of argument worked Kangaroos could not jump.

Way to not get the point - it's not about muscle mass, it's about mechanical construction. Humans are mechanically pretty weak, Sauropods are mechanically constructed to move with enormous loads.

Prove it can't fly.This is getting repetative: being bigger is not proof of lower gravity. Scaling up smaller creatures is not a valid comparison.

Oh, come on, this was laugh out loud funny:http://www.bearfabrique.org/marsmachines/mechjunk.html

Rubbish. The Ostrich is no more proof that birds that size can't fly than kiwis are proof that swans can't.

Come on, Red, what do you have to say?

Can we assume your continued silence means you have no answer?That being the case, could you at least show the strength of character to admit defeat?

In the What drove bird evolution? thread, Redwolf posted this (message #59) Since it's off-topic for that thread, I'll reply in this one.

No, I remember your failure to address any critism of the idea, and you're utter failure to demonstrate that is anything other than fantasy. Now that's just nonsense. The numbers don't come down on your side, at all. We've already shown that in this thread. As for everyone coming down on your side - hardly - again search this thread, or do a spot of googling. We never said you were. Trouble is, it doesn't make a difference if you're a lone crank of one of a little flock of cranks - you're still wrong. All of which we've already shredded in this thread. A shredding to which you've failed to present anything resembling a coherent rebuttal.