You and your friends successfully build a time machine and travel back 140 million years ago to the Cretaceous era to see the dinosaurs, all for your high school project. While you end up seeing the dinosaurs, you all end up finding modern humans, neanderthals, Denisovans, Homo floresiensis, Homo heidelbergensis and Homo luzonensis in futuristic clothes, having built advanced civilizations, domesticated dinosaurs, built floating cities, using renewable energy, having energy weapons, and more. You check the time machine and find it's not malfunctioning, you're not in an alternate universe, there's no signs these people time traveled, or extraterrestrial interference. This was incredible. Not only did all these humans evolve naturally here on Earth, they'd also made everything they saw.