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?
In: 296
We used to have plenty of megafauna, most of it went extinct fairly recently. mammoths, giant ground sloths, direwolves, giant elk are only a couple of examples. I believe some were hunted by humans (mammoths), others fell victim to the changing environment. The last ice age wasn‘t too long ago (technically it‘s still going on) and the largest and most specialized animals are always the first to die out, because they‘re just not as flexible as others. The ecological niches filled by megafauna are now mostly empty. give it enough time and animals will evolve back into their gigantic selves but that‘s not yet the case.
Also I think terrestrial mammals can‘t get as obscenely huge as dinosaurs because of a difference between the way mammals and reptiles work but I‘m unsure what it was.
Latest Answers