Dinosaurs ruled the Earth for about 165 million years, and they became extinct about 65 million years ago. Because it’s tough to understand exactly what such huge numbers mean, we can look at these numbers in a different way. We’ll look at these numbers like the calendar we’re used to seeing on the wall! If all of Earth time from the beginning of dinosaurs to today was turned into a regular calendar, the amount of time that dinosaurs were on Earth would last all the way from January 1st until almost the end of September! On the other hand, if we looked at humans on the same calendar, we would not show up until December 31st! That shows you just how long the dinosaurs were on Earth, and it shows just how little time we have been here in comparison!