Paper 24


Ramin Amir mardfar


Robert > what is your opinion of the differences between pterodactyl dinosaurs and the first birds or even birds today?

Ramin > The bat is a mammal which can fly.
The bats have no relation with bird's class.
Thus, pterodactyl was a reptile that could fly and had no relation with bird's class.
The pterodactyl is good evidence to this fact that the pressure of the air was great at that time. Compare wing's skeleton of a pterodactyl with wing's skeleton of a bird.
The bone of arm forms the main part of bird's wing. While the finger's bone, forms the main part of pterodactyl's wing. In the other words, the birds fly on their arm. While the pterodactyls (with their times larger body) only flow on their thin fingers.
We conclude from this that the wings of pterodactyls didn't tolerate a great weigh. This act comes to true when the density of air will be great.
The heavy (with high density) air, kept them floating in air.


Mike > Is it a pressure increase, or a gravity decrease that allows pterodactyls to become large.
Ramin > Both factors


Paper 25
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