Riley Black, author of 'The Last Days of Dinosaurs: An Asteroid, Extinction, and the Beginning of Our World', joins Cheddar Reveals to discuss the last days and extinction of the dinosaurs, and how the building blocks of life survived to eventually evolve into what we know today.

Cheddar Reveals

How Life Survived the Last Extinction-Level Event

Welcome back to Cheddar reveals, brought to you by curiosity stream Some 66 million years ago. An asteroid roughly seven miles across, slammed into the earth in the terrible mass extinction that followed? More than half of known species vanished seemingly overnight? How did this event affect a species? Not yet developed humanity? Well, joining us now is Riley Black, author of the last days of dinosaurs and asteroid extinction and the beginning of our world. Riley for the record. Got to know the true version of how the dinosaurs actually went extinct as far as we know and what misconceptions we hold about that event for a long time. It wasn't even really a question. I mean, the word dinosaur came up in 18 42 and for about 100 years after that, I was like, well they're these big, scary scaly reptiles, right, Why wouldn't they go extinct? It was really only relatively recently that we thought this was even a question and people have had lots of ideas ranging from, you know, dinosaurs had cataracts or maybe the climate got too warm or too cold or maybe there are caterpillars that ate all the dinosaurs food. Everybody had an idea that was really in 1980 that this idea of a massive impact. The evidence started to accumulate for it and paleontologists and geologists started to find things like the crater and that this really was an extinction that didn't just affect the non avian dinosaurs, but all life on earth altogether. So during that relatively short time period during the past 40 years, we went from this extinction being a complete mystery to something that we can really pin to this asteroid impact. What do we know about what survived that impact and how it laid the building blocks for the next generation of life on earth and as we mentioned mankind. Right. So part of what we know what we do about this extinction is we're looking for rock layers that document the last days of the cretaceous in the earliest days of the next time period called the paleo scene. And there's relatively few spots on the planet where we can get these kinds of rocks the before and after snapshots. What happened during this extinction? There are plenty of places where before we have the after, but it's relatively few that we can get the whole. And by looking at the fossil species that we find at the end of the cretaceous. In the beginning of the paley issue, we get an idea of who survived, who went extinct, what sorts of creatures are making their way through. And it seems to be that if you lived in a freshwater habitat, if you were something like a crocodile or a fish or a frog or a turtle, you were shielded from the effects of the impact, basically incredible searing heat that came after impact and the impact winter that followed or if you could burrow underground, if you're a small mammal, you can get into a burrow even getting 10 centimeters below ground, really shielded you from a lot of these environmental effects. And those included the earliest primates, the earliest primates that we know about lived at the same time as T rex and they survived into the Paleo Eocene. So our ancestors and relatives were there when this impact happened, it didn't just come up after the impact aftermath died off, that they made it through and that's really one of the most amazing things about this is all the species that we're able to hang on and survive. It's so fascinating. Do we have kind of an idea of what happened in even the days following? But the years, decades and centuries following this impact from that asteroid. Alright, it's relatively rare to get the kind of resolution we want from the fossil record, especially when we're thinking about something that happened 66 million years ago, that's so long ago. And it's rare to be able to say this happened within seconds or with ours, but within the past few years, with the discovery of some new fossil sites with new modeling techniques, looking at how the rock basically would have changed at the impact site around the planet after this extinction. Things like the firm spike, looking at pollen and spores in the fossil record to see when vegetation started coming back, we're able to get this more refined picture now and say, okay, once the impact occurred within about 24 hours, you're gonna have all this debris coming back down to the planet causing this heat pulse within minutes to hours of impact are going to have earthquakes and tsunamis, many parts of the world. But even to the time scale of like 100,000 years after that we have pollen records showing us that ferns are coming back for a million years after that mammals and other forms of life are starting to evolve in new and different ways. So it's really been within the past five or 10 years or so that we're getting this fine scale resolution on how this mass extinction played out. You mentioned something interesting in that earthquakes and tsunamis were happening in other places of the globe at the time of this impact because of that hit. So do we have an idea what else may have happened on, let's say the other side of the globe at this time. That's part of the big mystery. We know that this extinction affected the entire planet. We have a particular boundary layer called the K. PG boundary and you can find spots all around the world. It was first recognized I think in Italy that's been found as far away as Montana and New Zealand from each other and this has a lot of impact debris like small spirituals of glass or shot reports or remnants of this impact. So we know that a lot of the debris went all over the planet in terms of how life responded though. That's the big mystery. We can come kind of model some of the geological after effects. But what species made it, what dinosaurs and other forms of life are living on the other side of the planet and what were they doing and how were they affected by all these changes? We need the relevant rock layers to figure this out and there are a few and hopefully there are more, but that's the wonderful and sometimes frustrating thing about paleontology. There are far more rocks to look at. Then there are people to look at them. So I'm really hoping in the coming years they were able to find equivalents of North America's Healthcare, Hell Creek formation and get these before and after snapshots around the planet Really like 10 seconds. If something like this happened again today, how do you think it might be the same or different? It would be incredibly bad. It would be another mass extinction. A lot of creatures that probably make it through would be the ones that are able to get underground. So like my vote would be on the rats basically. I love it. So fascinating to have you on that's Riley Black, author of the last days of dinosaurs and asteroid extinction and the beginning of our world. Really great to have you on the show