Size of dinosaurs was because of gravitational pull?

Question

I heard a theory that the reason dinosoars were larger than the creatures on earth now is becuase of the gravitational pull. Has anyone else heard that? Any books or articles you know of for further research?

What are other theories that explain the size difference. I don't know a lot about science, but I'm extremely curious, so please be specific.

Answer 1

i heard something to do with magnetic field of the earth. at the time of the dinos it was 4 gauss and now only 0.4-0.7 gauss.

Answer 2

The old professor says: Of course the gravitational pull on Earth has not changed significantly for billions of years. The pull is a function of the planet's mass, and it hasn't changed much since the dawn of life on its surface.

Interestingly enough, gravity does play a role on how big they could have gotten (their upper limit on mass). Studies have show that flesh (muscle and sinew) can only cling to the skeletal structure up to a certain point before it would be ripped off the bone. If the animal were quite mobile, this weight limit would have to be much less because of the constant jerking of the muscle on the connective tissue.

It seems that "nature" is always experimenting to find the most economical, best energy conserving forms for living things. In this case, "nature" learned that "bigger is better" does not always hold true.

Answer 3

Just to throw this out.

I heard that the atmosphere had more oxygen in it and larger animals could develop without the energy output of deeper breathing or larger lungs.

How many calories could something gather in 1 day by eating just grass, leaves, etc. while keeping up the metabolism rate of being a very large animal. The body taking in more oxygen on normal breaths would offset this by a considerable amount.

Answer 4

the earth's gravity is no different now than it was a few hundred million years ago.

Answer 5

nO.....cause then we would also be giants