Dinosaurs
Thanks to the movies, we don’t really have to imagine too much what life would be like with dinosaurs still on this planet. Just look at the Jurassic Park films; clearly, we wouldn’t be able to cope with them! Contrary to what some people believe, dinosaurs and humans never co-existed.
At the time of the dinosaurs, only small mammals (such as primates the size of shrews) existed on the planet. There wouldn’t be any sign of modern humans for another 65 million years after the dinosaurs were wiped out. So, no, that means The Flinstones is not a historically-accurate cartoon!