Why were animals so much bigger in prehistoric times?

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Dinosaurs seemed to have generally been so much larger than animals today. Huge dragonflies that dwarf their modern counterparts, turtles 10ft long. What is the mechanism that allowed them to be so large, or conversely makes modern ones smaller? Is it about Oxygen levels, or efficiency, or something else?

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Anonymous 0 Comments

We focus on the big creatures, but in fact, there were vertebrates of all sizes.

The largest creature we know of is still with us [well, for now] the Blue Whale.

We, ourselves, probably killed off some mighty big mammals just recently, e.g., giant sloth, mammoth.

Natural selection sometimes uses size as protection if resources allow “big and dangerous” as an option. It follows that they’re preyed on by the ” big and bad-ass” predators.

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