Could we live in a dinosaur world?

0:00Hey, it's Flora Lichtman, and you're listening to Science Friday. In the new movie The End of Oak Street, bits of a suburban Michigan neighborhood get sucked back through time to a prehistoric world of dinosaurs. Exactly which geologic age is somewhat murky. But think Land of the Lost, just with Anne Hathaway. I think that our neighborhood has moved.

0:30We're in the past, aren't we? How the hell is that even possible?

0:41Which made us wonder, aside from the danger of getting snacked on by an allosaurus, what else would modern humans face in that ancient world? And we knew exactly who to call paleontologist Steve Prasati. Hey, Steve. Hey, good to speak with you guys again about dinosaurs in movies. Yes, thank you for this emergency taping. Had to get these questions answered. Okay, so if I got sucked back into the age of dinosaurs, and let's pick a time. Let's say the Cretaceous. Okay, like the day before the asteroid hit. Let's say that, maybe. Yeah.

1:12Sure. Sixty-six million years ago. Okay. What would I notice first? I think, first of all, you would notice that there would be T-Rexes chasing you down. And I think that would be pretty apparent. There would be a lot of dinosaurs. Not all of them would be huge, but many would be. And there would also be birds, but weird birds that had teeth and claws. And there'd be pterodactyls flying through the skies. You would notice that right away. I think you would also, you would notice that there were not very many mammals. If you saw a mammal, it would just be a tiny little one scurrying around. And you would not see any grasslands or prairies or savannas or any sort of environments like that.

1:55There were some little grasses that were just starting to evolve, but they had yet to reshape the landscape. Those would be the most obvious things you would see, but you would probably feel things too, because the atmosphere would be a bit different as well. Would I be breathing the same? Would the temperature be similar? The temperature generally would have been quite a bit warmer back at the end of the Cretaceous. And this was because there was more carbon dioxide in the atmosphere. And there are actually ways. It's really ingenious. There was a study that was published last year where some chemists and some paleontologists worked together to study dinosaur teeth.

2:34The enamel, the oxygen in the tooth enamel of these fossil dinosaurs actually is something of a paleothermometer. And it also can give insight into the amount of carbon dioxide when it was formed just by differences in the chemistry of the oxygen. And they actually found that during part of the age of dinosaurs, the amount of carbon dioxide would have been something like three times as much as there is in the atmosphere today. And even at the very end of the Cretaceous, when the asteroid hit, carbon dioxide had been falling a little bit, but it was probably something like maybe even double the amount that we have in the atmosphere.

3:10Now, we could have breathed that air, but the air would have been harder for us to breathe. You might be huffing and puffing a little bit. I would be. I know what it's like to cycle, to ride my bike up and down these hills here in Edinburgh, and I would not want to do that in an atmosphere with double or triple the amount of CO2.

3:28OK, what about disease? I mean, would modern diseases threaten the dinosaurs or would I be threatened by some kind of dino flu? I think it would work both ways and it would be a real concern. You know, from the fossil record, we can't really tell much about viruses. You don't get fossilized viruses, but you do see on dinosaur bones signs of infection. And there are some lesions on dinosaur bones, for instance, that really match injuries on bones in modern day birds and other animals that have a certain type of virus or a certain type of bacterial infection.

4:03So we do actually have, believe it or not, fossil evidence of viruses and bacterial infections. So it is something we'd have to concern ourselves with. OK, in the 10 seconds I have left, if you could be swept through a wormhole to the past, where and when would you go? I actually would love to see that last day of the Cretaceous, 66 million years ago, that morning where you would wake up and there would be T-Rexes and Triceratopses and duck-billed dinosaurs and pterodactyls in the air.

4:33And they would have no idea, no idea what was about to hit them, no idea how much the world would dramatically change. Wouldn't that be something to see those last T-Rexes? The eve of disaster. I feel like I learned something new about you today, Steve. Steve Prasati is a paleontologist and author of The Story of Birds, A New History from Their Dinosaur Origins to the Present, and he's based in Edinburgh, Scotland. This episode was produced by Charles Bergquist, and if you need a quick science fact check on a summer blockbuster or any other science-adjacent question, pick up that Flintstones Rockbell phone and call us.

5:11877-4-SY-FRI is our number. Have a great weekend. I'm Flora Lichtman.

5:18Have a great weekend. I didn't know. I'm Flora! Have a great weekend. I'll see you on Wednesday. Bye-bye.

5:28See you next time on Thursday! Bye-bye. We'll see you next time! Bye-bye. Bye-bye.