Is That a Dragonfly or a Seagull?

Let's say for a moment that you can travel through time. Whenever you want to go, no problem. So you pack up your bags and head to the late Permian period, around 250 million years ago. Once you arrive, you notice you're having trouble breathing. That's because the oxygen levels in the air were much higher during that time.

These same high oxygen levels are the reason for the creature you see flying towards you, skimming through the air on a fast, powerful trajectory.

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Meganeuropsis permiana, the giant protodragonfly of the ancient world.

It had a wingspan of close to three feet, and was nearly twenty inches long. It couldn't exist today, but back then the higher oxygen levels allowed for much bigger organisms.

If I were you, I'd probably go back to my own time at this point. With dragonflies big enough to snatch up kittens, you don't want to hang around long enough to find out how big the land predators were.