Can someone provide a satisfactory answer as to why the earth’s fossil record includes evidence of so many enormous creatures? Is it higher oxygen levels? Larger landmasses?
Can someone provide a satisfactory answer as to why the earth’s fossil record includes evidence of so many enormous creatures? Is it higher oxygen levels? Larger landmasses?
This program purports to answer you:
http://www.bbc.co.uk/radio4/science/thematerialworld_20040212.shtml
The whole discussion is on suggested evolutionary pressures which drove the appearance of the sauropods and the associated large carnivores. The reason why similar pressures haven’t developed in the Cenozoic, however, isn’t explicitly addressed.
Indeed, isn’t there a similar proliferation of large animals today? Elephants are rougly the same size as a T-rex, and blue whales are bigger than the sauropods.