Every breath you take has a prehistoric connection—you’re breathing the same air as dinosaurs! The Earth’s atmosphere is a closed system, meaning the air molecules we have today have been around for billions of years, constantly recycled through natural processes. Scientists estimate that about 1 in every 5 breaths you take contains air molecules that were once exhaled by a T. rex or a triceratops 66 million years ago.

Here’s how it works: the air is mostly nitrogen (78%) and oxygen (21%), with trace amounts of other gases like argon and carbon dioxide. When dinosaurs roamed, they breathed the same mix, exhaling carbon dioxide that plants then turned back into oxygen through photosynthesis. Over millions of years, those molecules have been mixed and redistributed by wind, weather, and chemical reactions, but they’re still here. Even water molecules in your glass might have been sipped by a diplodocus—about 97% of Earth’s water has been around since the planet formed.

This means the air in your lungs right now has been through countless creatures, from dinosaurs to ancient humans like Cleopatra. It’s a wild reminder of how connected we are to the past, even in something as simple as a breath. Next time you inhale, think about the dinosaurs who shared that air—it’s a science bite that’ll make you see the world differently. Share this with your friends and come back for more on ReelFact!