The Ancients - The Rise of the Dinosaurs

Episode Date: March 24, 2022

Dinosaurs! Spectacular resilient beings who were able to adapt and survive the most terrifying of events. Evolving from a group of mostly humble-sized creatures, into the most enormous beasts that ever existed on land. But how did the first true dinosaurs emerge? In this episode, Tristan is joined by Professor Stephen L. Brusatte. Stephen is a Palaeontologist and evolutionary biologist who specialises in the anatomy and evolution of dinosaurs. He takes us through not just the evolution of dinosaurs, but the development of the new world and ecosystems that allowed them to thrive. What can we learn from the magnificent creatures who ruled the earth before us?Stephen L. Brusatte is the author of 'The Rise and Fall of the Dinosaurs: A New History of a Lost World', published by Picador.For more Ancients content, subscribe to our Ancients newsletter here.If you'd like to learn even more, we have hundreds of history documentaries, ad free podcasts and audiobooks at History Hit - subscribe today!To download, go to Android or Apple store.

Hi, I'm Tristan Hughes, and if you would like the Ancient ad-free, get early access and bonus episodes, sign up to History Hit. With a History Hit subscription, you can also watch hundreds of hours of original documentaries, including my recent documentary all about Petra and the Nabataeans, and enjoy a new release every week. Sign up now by visiting historyhit.com slash subscribe. It's the ancients on History Hit. I'm Tristan Hughes, your host. And in today's podcast, well, we're going back again. We're going way back into history, into prehistory, into before modern humans, human sapiens, because we're talking about the dinosaurs. There's just something about dinosaurs which fascinates everyone, myself included. I don't know about you, but I remember watching many, many years ago now, on the BBC,

there was a famous miniseries called Walking with Dinosaurs. That really got me so interested in dinosaurs back then. In particular, the first episode, all about the Triassic, when dinosaurs weren't dominant. There were other creatures which really came to the fore, including these giant crocodile-like creatures that were dominant on land, such as the famous Postosuchus. Now, I mention all this about the Triassic because that's the topic of today's podcast. We're talking about the rise of the dinosaurs, the dawn of the dinosaurs. So we're going to be focusing in on what we know about dinosaurs during this earlier period, during the Triassic period. And with me to discuss all of this, I was delighted to get on the podcast, Dr. Steve Brissatti from the University of Edinburgh. Good old Edinburgh, my old university grounds. Now Steve,

he is Mr. Dinosaur Man. He is a leading paleontologist. He's a great speaker. It was wonderful to get him on the podcast to talk about the rise of the dinosaurs. And if you like this content, then don't worry, we've got more dinosaur content coming your way in due course. Steve, he's written a new book, The Rise and Fall of the Dinosaurs. We're just covering the rise in this episode, but don't worry, we'll be looking at the fall in due time too. So without further ado, to talk all about the rise of the dinosaurs from the beginning of the Triassic all the way to the dawn of the Jurassic, the famous Jurassic, here's Steve. Steve, thank you so much for taking the time to come on the podcast today.

My pleasure. Really happy to talk dinosaurs. I mean, absolutely. Dinosaurs, dinosaurs, dinosaurs move over ancient Rome, ancient Greece and the like because we're going millions of years further back. And Steve, first of all, with dinosaurs, it just seems to be something about dinosaurs for everyone. It enthralls, it grips almost everyone that you talk to. There's just something special when talking about dinosaurs. There is, and I wish I could explain it. I don't have a good grasp of why that is. There's just some magic, though, about dinosaurs, something indescribable about them that captivates people,

and it captivates so many of us from such a young age. And I think there really is something special about going to a museum, standing underneath the skeleton of a dinosaur, marveling at these ancient, often enormous animals from millions and millions of years ago. But it's not only going to the museums and being in their presence. It's simply reading books about dinosaurs, seeing dinosaurs on the screen and TV shows and in films. You know, I have a two-year-old son and he already has taken a real shine to dinosaurs. He has no idea what I do for a living, but you know, there's just something about these animals that just grabs you. And I think that sort of magic has led me along. And in this new book, which we're going to be talking about, the Folio Society edition of my book, The Rise and Fall of the Dinosaurs. I think it's captured there, not just

in the book itself, but in all this new artwork that the Folio Society has put in. And I think when you look at these images, you see these dinosaurs just thundering across these ancient worlds. There's just something about them. And I know I'm rambling there because I don't know what else to say. But what I would say is just that I think when it comes down to it dinosaurs are more fantastic than any dragon or unicorn or sea monster or leprechaun or you know anything humans have ever come up with in myths and in legends but dinosaurs were real they were very much real they were fabulous and they lived on this very same world that we now live on I think you're right right there. And you ramble on my friend, because, you know, it's the passion talking right there. But Steve, I think you're completely right on that. And it's almost as if

it's the same with us history buffs. When we start talking about the real history of things, it's even cooler than, as you say, the myth, than like the fictional stuff. Because as you say, this stuff really happened. This happened in our past and we have the evidence to prove it. And dinosaurs are exactly the same as that, as you just highlighted i guess if we focus in as say we're going to be talking about the rise of the dinosaurs today and some people might think when you say rise of the dinosaurs they may think words like the triassic period or the triassic but i'd like to go a bit beyond that to start off and to the period before the triassic because steve when are we talking how many millions of years ago and to the period before the Triassic. Because, Steve, when are we talking?

How many millions of years ago? But what was happening before the Triassic period, when we're in this period called the Permian period? So first, I'll just say I love talking dinosaurs with the historian, because, you know, although the two fields may seem quite different, paleontology and history, really, we're doing the same things. I mean, we're going into the past and we're trying to find clues from the past, whether in my case, it's fossils, in the case of historians, it's artifacts, it's manuscripts, and so on. But we're trying to find those clues. We're trying to understand what the world was like and how the world changed and how the world dealt with catastrophe and cataclysm. And hopefully we can learn from that past. And with dinosaurs, dinosaurs tell us

so much about how real organisms, real ecosystems have responded to all of these different things that the earth and the climate throw at organisms over the years. So dinosaurs dealt with changing climates, they dealt with global warming, they dealt with rising sea levels, falling sea levels, volcanoes, asteroids. So we can learn a lot about them. And one of these big lessons comes right from the start. And that is at this time in the Permian period, this was before the dinosaurs, there was a major catastrophic event that helped launch the dinosaurs,

that basically gave the dinosaurs their opportunity. And really they only got that opportunity because the world was reshaped by this catastrophe. And this catastrophe was a great mass extinction at the end of the Permian about 252-ish million years ago. Now, right before this catastrophe happened, the world seemed pretty stable. It was a very different world from today. This was the time of the supercontinent Pangea. So all of the land was gathered together, stretching from North Pole to South Pole. It was very hot. It was very dry across much of that continent. It was a tough place to live on, but there were plenty of plants and animals that were well adapted to that world,

including many early relatives, ancestors of us, early members of the mammal group. early relatives, ancestors of us, early members of the mammal group. But then, at the end of the Permian, 252 million years ago, these big volcanoes started to rumble in what is now Russia. And these were not any normal volcanoes. There was basically this huge well of magma that parked itself under Siberia, and it percolated up through the mantle, through the crust, and it erupted. But it didn't erupt in the way that the Hawaiian volcanoes erupt, or Mount Pinatubo, or Mount St. Helens, or any of the volcanoes that we are used to. Instead, this lava just flowed out like blood from a wound for millions of years. And by the end of this time of these mega volcanoes, you had And by the end of this time of these mega volcanoes, you had many, many thousands of square miles, square kilometers covered in lava, scorched, destroyed.

But more than that, than the actual lava, the problem was all of these gases that came up with the lava. As the magma kind of percolated through the crust, it baked and burned the rocks that it came into contact with. And that released a lot of carbon dioxide. It released a lot of methane, it released these powerful greenhouse gases, and those led to global warming. And that global warming was extreme, and it was intense, and it happened very quickly, and it caused ecosystems to change so fast that up to 95% of all species died out. It was the closest life has ever come to completely being erased. And so that moment in Earth history, I think it's obvious why that is an interesting moment for us to study, but a very relevant moment.

This was a catastrophe. This was when climates change quickly and dramatically. We want to study this. We want to understand this. And what happened then, a lot of stuff did die. The recovery did take a long time, but not everything died. And out of the ashes of that extinction, there were some survivors. And one of those survivors was a group of small reptiles, just about the size of house cats, long, skinny arms and legs that they would run on. They were fast runners, they were agile, they were energetic, and these were the ancestors of the dinosaurs. But they really only got their

start because they were able to survive that apocalypse and then found this new world on the other side. Almost everything was dead and that world was theirs for the taking, but there were plenty of other types of animals that were also surviving. Again, not a lot, you know, 5% of stuff survived, but still that was enough. And so in this new world, as the earth healed, the volcano stopped erupting, you had these new plants and animals vying for supremacy on this supercontinent of Pangea. That's the origin story of the dinosaurs. And Steve, is this the time where we get, I've got words down here on my notes, such as archosaurs and dinosaur morphs. Is this the time where we get, I've got words down here on my notes, such as archosaurs and dinosaur morphs. Is this the time when we start seeing these types of creatures emerging? That's right. So this is when we see what we call dinosauromorphs. That's a fancy name. It's

a technical name. It's a little bit of a tongue twister name. Basically, that means these are the very closest cousins and ancestors of dinosaurs. They're not quite true dinosaurs. What we call a true dinosaur, it's a definition. It's kind of like where you put the border between two countries, you know? The land looks the same on either side of the border, but we do this on the family tree of life and we have to draw lines.

And we say, you know, that dinosaurs are all of those animals that have certain types of features of their skeletons, things like extra bones in the pelvis, backbone linking to the pelvis, and a big open window for the thibone. Very technical things of the anatomy that makes a true dinosaur a true dinosaur. But these dinosaur morphs were the animals that were on the cusp of becoming dinosaurs. They were the ancestors of dinosaurs. We see their fossils

materialize, emerge from the fossil record within at most one million years of those volcanoes. So they were immediately taking advantage of this new world. And so the first fossils we have are actually footprints and handprints, these ghostly impressions that these tiny, humble little dinosaur ancestors left behind as they were racing along the mudflats around the rivers and lakes of Central Europe about 250, 251 million years ago. That is quite something. Well, keep on that a bit longer then. And I know it sometimes feels like a very simple question to ask, but you mentioned how for a true dinosaur, it needs to have these

certain traits, these certain qualities, as it were. So in certain respects, what is a dinosaur? How do we define a dinosaur? So it really is a matter of convention. And that's true of any sort of classification of species. You know, classification is a human exercise. Evolution doesn't tell you what is a bird, what is a dinosaur. These are labels humans put on things in order to categorize them and understand them. And it is in many ways similar to national borders in the same way that national borders are arbitrary, and in a sense, I mean, they're lines drawn on a map. But there are reasons there are borders, there's history, you know, borders change over time because of wars, because of politics. And so with classification,

it's kind of similar, we draw these lines on the family tree of life, but these things have historical relevance. And a lot of times why we put a line on a certain place on the tree and say, oh, the members of this branch of the tree, we're going to call them dinosaurs. It's because hundreds of years ago, some posh Victorian scientist first identified a few bones that he called dinosaurs. And so that kind of crystallized the definition. But when it comes down to it, scientifically we define dinosaurs as all animals that stem from the most recent common ancestor of Iguanodon and Megalosaurus. Okay, and why do we say that? Well, Iguanodon and Megalosaurus were the first two dinosaurs that were identified, studied, described by western scientists in the early 1800s. They were the first things that

people really understood were these ancient giant reptilian animals. So for historical reasons, those are the two linchpins. And so we take those as anchor points on the family tree and we say, we can trace those two animals. We go down to their common ancestor on the family tree and we say, look, anything that can go back to that ancestor by definition is a dinosaur. And so in practice, we can tell that those animals have certain features of their skeletons, you know, because of course the family tree is all about genealogy. It's all about ancestry. Things that are closely related are going to have features that they share that other things don't. So that iguanodon

and megalosaurus group on the family tree, they have extra backbones in the pelvic region. That's to support bigger hind limbs, stronger muscles. They have a big open joint in the pelvis where the thigh bone fits in that help these animals walk upright, walk more efficiently. And there's a few other small features, But I know that may seem like kind of an unsatisfying definition, but it's true of anything. You know, what do we call a mammal? What do we call a bird? These are all human terms, human conventions to try to make sense of the vast diversity of species that are alive today and alive in the past. Okay, so going on from that and those definitions, and I appreciate it's a bit of blurred lines, as it were, but when did the first, when do we think the first true dinosaurs emerged

during the Triassic? The first fossils of things that we can call true dinosaurs, so members of that Iguanodon megalosaurus group on the family tree that have the extra bones in their pelvis and the big window shape opening for the thigh bone. The first fossils of those types of animals are about 230 million years old. They come from later on in the Triassic period, a good 20 million years or so after those volcanoes caused the Great Extinction, and a good 20 million years or so after the first dinosaur morphs, those immediate ancestors of dinosaurs were leaving their tiny footprints in Central Europe. But these are just the oldest fossils. The oldest fossils, they just put a bound on it.

They put kind of a minimum bound. You can always find stuff that's older. I mean, somebody might go out tomorrow and find something that's 5 million years older. So in reality, probably true dinosaurs originated, my best guess is somewhere between, you know, 235, 240 or so million years ago. And I think somebody will eventually find a fossil that's that old. In any case, it doesn't matter too much. You know, we know that in the Triassic period, the ancestors of dinosaurs survived that great extinction. Soon afterwards, they started to proliferate, but they remained small. They remained pretty humble. Then later in the Triassic, you got a bigger diversification of dinosaurs. We'll definitely delve into that diversification very, very quickly.

But one place I'd love to talk a bit more about for these very early dinosaurs, it seems we're going to Argentina. It's this place called, and correct me if I've got my pronunciation completely wrong here, Iscagualasto. This was a really rich location for early dinosaurs. The dinosaur origin story, a whole lot of it, extends to this place, Ischigualasto in Argentina, the Valley of the Moon, an otherworldly landscape, a desert, badlands type of landscape. And the badlands are sculpted out of Triassic rocks, and those rocks in places are bursting

with bones, bones of dinosaurs, bones of crocodiles, bones of pterodactyls, bones of other reptiles and amphibians, all kinds of things that were living and thriving about 230 million years ago. So, you know, this is, again, about 20 million years after that horrible extinction. By this time, the Earth had recovered, entirely new ecosystems had emerged you had this new world where there were now dinosaurs crocodiles pterodactyls the very first true mammals turtles so many of the animals that we know today that are still very important parts of the world today they got their start in the triassic and by 230 million years ago they were forming these entirely

new ecosystems of which dinosaurs were a part. But dinosaurs were not the dominant animals in those ecosystems. They were there, but they were not at the top of the food chain. They were not the most diverse animals. They were not the most abundant animals. Dinosaurs really were role players during most, if not all, of the Triassic period. So what were the dominant animals at that time then, Steve? In the rivers, in the lakes, near the water, you had enormous amphibians. You had basically what were salamanders that were the size of small cars. These terrifying creatures, hundreds and hundreds of sharp teeth in their mouths, and they form flocks. There were hundreds, maybe thousands

of these giant salamanders that lived together in social groups. They would have clogged the rivers and the lakes. They would have mostly been fish eaters. But if you were one of these small early dinosaurs and these first dinosaurs, they were small. They were only the size of humans. Most of them are the size of dogs. A few got up to the size of horses, but most were quite tiny. They were nothing like a T-Rex or a brontosaurus. That would all come later. So the first dinosaurs, they were meager animals, really. And so they would have wanted to avoid the shorelines at all costs because those giant salamanders would have been lurking there. But the dry land was no better because the dry land, that was the domain of the

crocodiles and their cousins. So, you know, in today's world, there's only about 25 species of crocodiles and alligators, and they're all kind of the same. They all live in the tropics or the subtropics. They live at that interface of water and land. They can swim. They can move on the land a little bit. They're hunters. They fish. You know, we all know what crocodiles are like. But back in the Triassic period, this was the time when crocs really flourished. And there was an enormous diversity of crocs and their extinct cousins. And there were ones that were apex predators, ones that had heads that looked like the heads of T-Rex, you know, giant bone-crushing teeth. There were ones that had armor and spikes all over their bodies. There were ones that didn't

even have any teeth. They lost their teeth and they had beaks to eat plants. There were some that only walked on their hind legs. I mean, just this incredible, rich menagerie of ancient crocs. And they were the ones that really controlled the food webs on land. They were the top predators in most ecosystems. They filled many different ecological roles, big predators, small predators, plant eaters, omnivores, and so on. ecological roles, big predators, small predators, plant eaters, omnivores, and so on. And the dinosaurs really slotted in to what was a croc-dominated world. But then that, of course, ended a little bit later, and there was another catastrophe that paved the way for the dinosaurs to take over. I will get to that. Absolutely, Steve. I mean, just quickly, I was a huge fan

of Walking with Dinosaurs when I was growing up. And I remember the first episode and they say, is it Postosuchus or something like that? It looks like a dinosaur, but that's not a dinosaur. You're absolutely right. That thing, it's a croc. It's a close cousin of crocs. It's something technically called a Rauasuchian, but that's the fancy name for this group of ancient crocodile relatives. But if you look at this thing, Postosuchus, you know, you think it's a dinosaur. I mean, it's big. It's reptilian. It has sharp teeth. It has sharp claws. It has a big head and a big mouth and, you know, clearly a big top predator type of animal. But it was not a dinosaur. It would have eaten dinosaurs. But this is a perfect example of what crocs were doing back then. There are no

crocs today, thankfully, I would say, that are anything like a Postosuchus. We don't have to worry about just going out, taking a walk, riding our bike, and having some five, six, seven, eight meter long killer croc just lurking in the shadows, ready to jump out and crush us with its jaws. But the first dinosaurs did. That was the world that they lived in. Did Edison really take credit for things he didn't invent? Were treadmills originally a form of corporal punishment? And would man have ever got to the moon without the bra? You can expect answers to all these questions and more in the brand new podcast from history hit

patented History of Inventions. Join me, Dallas Campbell, as I uncover what really sparked history's most impactful ideas. Each episode, I'll be recruiting the help of experts, scientists, historians, and even a few real-life inventors. Subscribe to Patented History of Inventions wherever you listen to your podcasts. Whether you're in your running era, Pilates era, or yoga era, dive into Peloton workouts that work with you. From meditating at your kid's game to mastering a strength program, they've got everything you need to keep knocking down your goals. No pressure to be who you're not, just workouts and classes to strengthen who you are.

So no matter your era, make it your best with Peloton. Find your push. Find your power. Peloton. Visit Peloton at onepeloton.ca. so as the triassic progresses and as you say we're going to get to the end of the triassic very very soon but if we're talking about the late triassic period now and the status of dinosaurs then just before the end of the Triassic and the real rise of the dinosaurs. We seem to have this one other

extraordinary archaeological site that seems to shine a light into this late Triassic world and the role of the dinosaurs at that time, the diversity of the dinosaurs and how they fit into the system etc. And I've got my notes here the name Ghost Ranch. Now Steve talk us through Ghost Ranch, this site, and what it's telling us about the dinosaurs in the late Triassic. Ghost Ranch is a really special place for understanding early dinosaurs. And it's just a special place in general. And I profile it in the book, The Rise and Fall of the Dinosaurs.

And it's a very important story early on in the book I tell about Ghost Ranch. Some good friends of mine have worked there for a few decades now, actually, a group of young scientists, and they've been finding a huge wealth of bones of early dinosaurs, along with some of these crocs and amphibians and other things they were living with in the Triassic. But it was actually many, many decades earlier that the first fossils were found there. And these were found by an expedition that found a graveyard of skeletons of a very early meat-eating dinosaur, a very primitive cousin of T. rex. And that was around the time when those fossils were first found that Georgia O'Keeffe was out in Ghost Ranch. So Georgia O'Keeffe, you know, the great artist, she moved out to Ghost Ranch because apparently the story

says she thought the light out there was like the best light, just the perfect light, the natural light of the sun shining on those badlands, on those candy-striped hills and gullies. She just loved that. And of course, it was a very common motif in her work, those sort of southwestern landscapes. But she lived in Ghost Ranch, was this most famous citizen. She's what Ghost Ranch is most known for, I think, in general. But I think it surprises a lot of people and a lot of art enthusiasts that this place that Georgia O'Keeffe made so famous actually is one of the best known fossil sites for early dinosaurs. And what Ghost Ranch shows is that even later in the Triassic period, I mean, we're getting late. So the Triassic period was 50 million years

long. It started about 252 million years ago with that great extinction at the end of the Permian. It then continued for about 50 million years. And throughout that entire time, really dinosaurs were not that special. And Ghost Ranch is a linchpin because it comes from later in the Triassic. And, you know, we're talking about a span that's kind of 220-ish to 210-ish million years ago. There's lots of different fossil sites in that area. But still, at that time, dinosaurs are not very preeminent in any way. You don't have anything that looks like a T. rex or a brontosaurus. You don't really have any dinosaurs that are larger than a horse. You have different species of dinosaurs. You have meat eaters. You have plant

eaters. You have members of some of the different groups, but it's a small diversity of dinosaurs. They still very much are role players in their ecosystems at that time. And I think that's really interesting. I mean, it means that the first 50 million years of dinosaur history, give or take, the dinosaurs were not dominant. They were not very special. They were just one of many groups of animals that were trying to make a living on the supercontinent of Pangea during this time the Earth was recovering from that great extinction. And there were other groups that not only were eclipsing them, there were other groups that had eclipsed them. This was a croc world. This was an amphibian world. The dinosaurs seemed to just slot in there. But we know that would change. So Ghost Ranch is a picture of

that kind of world before the next catastrophe would happen. Well, let's now go on to that next catastrophe. Because, Steve, how do dinosaurs therefore topple the crocs and become dominant? It was another stroke of either fortune or misfortune, depending on how you look at it. But it's one of those great contingencies of Earth history. And, you know, it's the same thing in human history. Just think of all the small little things, the turning points where major things happen. There's some small trigger and the domino effects are enormous.

And these things are unpredictable from the start. And a lot of times they have nothing to do, at least in evolution, with the animals themselves. They have everything to do with the environment. And sometimes the environment changes so drastically, so radically, so quickly that organisms are shaped by that and have to endure that and have to adapt to that. And some do and some don't. And so sometimes these sudden environmental shifts, they really do reset the evolution of life and they set life on radical new courses. And that's what we see at the end of the Triassic period, about 201 million years ago. The supercontinent begins to break apart. And of course it did. I mean, this is why we have separate continents today. This is why there's a North America and a Europe. This is why there's South America separated from Africa. That all happened 200

million years ago as that supercontinent began to break. Now, the dividing line today is the Atlantic seaboard. The Atlantic Ocean fills that gap where those continents used to be connected, which is why South America and Africa fit together like puzzle pieces. But that process took a long time to pull the crust to that extent where an ocean could come in. So initially, as Pangea began to break apart, the Earth bled lava again. It was another time of great volcanic eruptions, kind of like the ones 50 million years earlier. Not quite as severe, not quite as much lava. They didn't last for quite as long. They lasted for about 600,000 years this time. But still, you had all this lava, you had all this carbon dioxide and methane coming up with the lava that led to global warming.

It led again to a mass extinction. Less severe, but still a great extinction where plants and animals all over the world succumbed to death all at the same general time. And what happened then was that the crocodiles and those big amphibians, they were hit really hard. They were the big victims of that extinction. They didn't totally die out. A few crocs made it through, the ancestors of today's paltry diversity of crocodiles. But all of these apex predator crocs and ones with spikes and ones with beaks and ones that walked on two legs and that ate plants and all these things, they died in that extinction, in that global warming caused by the

volcano. Same with a lot of the big amphibians. Dinosaurs, though, were the great survivors of that extinction. They sailed right on through. It's like they didn't even notice that the world was burning around them. It's remarkable. So they showed adaptability and resilience at that time. We don't know exactly why. You know, there's no clear good answer yet. Somebody will find the answer. And I think it is the biggest mystery about dinosaurs we still need to solve. And that is what allowed them to deal with that global warming and those volcanoes so well when their competitors, the crocs and the big amphibians, the things that had been keeping them down for tens of millions of years, didn't deal with that extinction well. We don't know the answer.

There are various ideas out there, but I think it's something that somebody in the next generation of paleontologists is going to figure out. Well, that's really exciting indeed to know that, you know, there will be hopefully an answer to that question very soon, that huge question. And there's also, especially as a Joe Bloggs listening to you now, also given the size, as you say, that most dinosaurs at that time, they weren't that big too. I mean, are dinosaurs the main, I guess, victors of this event or do mammals also survive or is it just mainly the dinosaurs? Mammals are another survivor of this extinction because mammals go back to Pangea, to the Triassic. Mammals originated right around the same time as dinosaurs, which is a fact that I think surprises a lot of people. We think oftentimes of mammals

as the successors of the dinosaurs. Well, the dinosaurs died. I know we're getting way ahead of ourselves, but you know, the asteroid came, killed off the dinosaurs and mammals took over. But actually mammals and dinosaurs go back to the same time. Their origin stories go back to the same time and place, the supercontinent of Pangea in the Triassic after that terrible and Permian extinction. The mammals, stayed small, stayed in the shadows. The dinosaurs eventually got bigger. So mammals and dinosaurs went their own separate ways. And over the next, you know, many tens of millions of years, the dinosaurs kept mammals from becoming big. You know, dinosaurs were incumbent in those big ecological niches. But mammals, we shouldn't sell them short because they did the opposite.

They prevented dinosaurs from becoming small. You know, you never had a Triceratops or a Stegosaurus get down to the size of a rat or a mouse. Why? Because the mammals were really good in those roles. So mammals also survived that extinction at the end of the Triassic. They were victors alongside the dinosaurs when the crocs and the big amphibians and so on died out. So there may be something about being small, because remember the dinosaurs at this time were still small. There were no T-Rexes yet. So maybe being small was part of it. Mammals grow fast. Mammals reproduce fast. I mean, maybe those are parts of it too. Mammals

keep themselves warm with hair. It helps control our body temperatures. It can help buffer us against big changes in climate. We know now a lot of dinosaurs had feathers. Maybe it was because dinosaurs in the Triassic had feathers. That helped them to survive periods of climate change. It's quite speculative. We don't have a good answer. But my guess is it has something to do with dinosaurs being small,

with having feathers, with being able to grow and reproduce fast, similar to mammals, which also survived. Steve, this has been great. A couple more questions as we start wrapping up this Rise of the Dinosaurs podcast episode. I mean, so following this great disaster, which the dinosaurs have emerged the victors, so to speak, of, you get the start of the famous Jurassic period. And you mentioned how dinosaurs start to get really big. So how do they take advantage of, I guess, of this great extinction event to therefore start getting really big, to become dominant? How do they take advantage of this new world that they survive and manage to thrive in?

So now there's this extinction. take advantage of this new world that they survive and manage to thrive in. So now there's this extinction. A lot of the crocs, a lot of the giant amphibians are wiped out. Dinosaurs survive. The Triassic has ticked over to the next period of time, which is the Jurassic period. And this is when dinosaurs truly take over the world. And this is why the book and the film is Jurassic Park. If it was Triassic Park, it would be a film about big crocs and big salamanders, which would be pretty cool, but it wouldn't be the same. It wouldn't be about dinosaurs. It's only in the Jurassic that dinosaurs really become spectacular. Whether you're in your running era, Pilates era, or yoga era, dive into Peloton workouts that work with you. From meditating at your kid's game to mastering a strength program,

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empire. In the Triassic, they were still restricted to certain pockets, only certain climates, certain latitudes could dinosaurs live well in. In the Jurassic, they spread everywhere. They migrate everywhere. And you find them really all over the world, any kind of environment on land. In the Jurassic, you see dinosaurs get bigger. And you see meat-eating dinosaurs grow into things like the size of buses. You see the plant-eating dinosaurs with long necks become even bigger. Some of these things eventually become the size of Boeing 737 aircraft. You know, amazing to think of a living animal that has to eat and breathe and move and be born and grow up and so on, you know, the size of a jet plane. But that all happened in the Jurassic.

And it seems like more than anything, it was having that open space after the extinction that allowed dinosaurs to experiment and allowed them to do new things, to adapt to their new world. And that just led to their diversification. Now, some of them did become really big. That is like these ones that became the size of jet planes. That has been a longstanding question as, you know, why was that? What allowed these dinosaurs to become so big? Why have no mammals that have

lived on land ever become that big? Of course, mammals that live in the water, like whales, are even bigger than dinosaurs, but the water is a whole different realm. You don't have to worry about hoisting yourself up against gravity and, against gravity. But on the land, the biggest mammals were only a fraction, maybe a quarter of the size of the biggest dinosaurs that ever lived. And the Jurassic is the real nexus of all this. That's where dinosaurs are becoming huge. And it seems like something that was integral to that was the development of a new type of lung. So the way that dinosaurs breathed, at least a lot of dinosaurs, was much more efficient than the way that we breathe, the way that any mammal breathes. Dinosaurs could take in a lot more air with each breath, a lot more oxygen with each breath than mammals. And you might say, how in

the world do we know that? I mean, do we find fossilized dinosaur lungs? You know, how do we know about how they breathe? And we don't find their fossilized lungs. Lungs are, you know, basically bags of tissue. They're so soft, they decay away so quickly. But what we do see are the marks that the lungs left on the bones. And this is really intriguing. Modern day birds have these distinctive lungs that take in more oxygen than mammal lungs. That's because when they breathe in, some of the air with oxygen goes across the lungs immediately.

Some of the air is shunted off into air sacs, into these little balloons that connect to the lungs. And then when the bird breathes out, those air sacs deflate. That air in those air sacs still had oxygen. So that goes across the lung when the bird breathes out. So when the bird breathes in and out, it takes in oxygen. Many dinosaurs had those same lungs. How do we know? Because those air sacs, those balloons that store air, they actually leave marks on the

bones. They invade the bones because they're invasive. They go all over the skeleton, all over the body. You know, the bird needs space for these air sacs. So we see those marks on dinosaur bones. That tells us they have the same lungs as today's birds, these extra efficient lungs. So if you can take in more oxygen, that would help you get bigger. Not only that, but those air sacs actually hollow out the bones. So they make the bones lighter and more limber. You know, these dinosaurs like brontosaurs, they were huge. They were colossal

animals, but they were not bulky, really. They were quite flexible. They could move quite easily. Their bones were really lightweight, like a well-designed skyscraper. And also those air sacs are an air conditioning system throughout the body. And shedding heat, keeping cool, is always a problem for big animals. So it does seem like those lungs with those air sacs may have been a major reason why some dinosaurs were able to get so big and certainly were able to get bigger than mammals. And this was all happening in the Jurassic period after that extinction. Steve, it is extraordinary. I mean, as I said, this really feels like the golden age of the dinosaurs, as it were, as you mentioned, they spread across the globe. The amount of diversity is extraordinary. Carnores herbivores omnivores etc etc etc

but as we mentioned we've been talking about the dawn of the dinosaurs today the age of the dinosaurs the golden age and the fall those will be for other podcasts but i mean just to wrap up as a last thing it must be great as a paleontologist, or really interesting, shall I say, to look at dinosaurs in the Triassic and perhaps the iconic dinosaurs like the Coelophysis or something like that, a small dinosaur, and then to see how different dinosaurs are in the following Jurassic with the likes of Allosaurus and the like. It must be extraordinary just looking at this evolution of the dinosaurs across these two different periods and the events which cause them to become the dominant creature on land and sea. It is absolutely fascinating. And it's another thing that's hard to put into words, but there is just something really special about being a scientist that goes out, looks for fossils. When we go out and we look for fossils, we have no idea what we're going to find. Any fossil is a clue. It's a clue to a world that's hundreds of millions of years old. These

fossils belong to plants and animals that don't live anymore. You're the first person to see this thing when you find it. There's a real magic there. And I try to convey that magic in the book. So in the Rise and Fall of the Dinosaurs book, I tell the story of dinosaur evolution from their humble origins to their evolution of enormous size. And of course, some dinosaurs became birds. I tell that whole story, how some dinosaurs got small and evolved feathers and wings and started to fly. And then, of course, we talk about the extinction of the dinosaurs. I tell the whole story in the book, and now it's super richly illustrated in the new Folio Society edition, which I'm really proud of. But the other thing I try to do in the book is just convey now it's super richly illustrated in the new Folio Society edition, which I'm really proud of. But the other thing I try to do in the book is just convey what it's like to be a

paleontologist. How do we find fossils? How do we study fossils? What it's like to be one of these scientists who gets to pursue this childhood dream of digging up dinosaur bones for your job. And it is a fascinating thing. And I think when I study early dinosaurs, the sense I get is just how humble those first dinosaurs were and how long it took for dinosaurs to become splendid. That doesn't really jibe with at least what we used to think about dinosaurs. You think a T-Rex, you think a Brontosaurus, you see the grandeur, the majesty, the size of those animals. And I think it's natural to just think, well, there was something so special about them that endowed them to just take over the world as soon as they

originated. They were the dinosaurs after all. But what we see with this early history of dinosaurs is no, dinosaurs had a very, very meager origin story. I mean, they were these tiny animals. They stem from ancestors that endured the worst catastrophe in Earth history. And then for tens of millions of years, then they had to cope with other animals that had also survived that extinction, but were becoming bigger and were becoming more diverse. And it was only, you know, a second extinction, a second unpredictable cataclysm that allowed dinosaurs to vault past those crocodile and amphibian rivals. You put all that together, it's a pretty rich story. It's a neat story. It's a fun story. It's a story about evolution. It's a story that gets at this question, how does a major group of animals become dominant? How does it work?

And I think you could ask that in history as well. How does a country like the United States become a superpower? How does a country like Great Britain become a great imperial power? What are the steps that make that? These countries aren't just born. And the same thing with the evolutionary dynasties. Dinosaurs, mammals, whatever the case is, they're not just born. They have to be made and they have to be made over millions of years of evolution. And it's not just the animals themselves, but it's the worlds they live in. And those worlds are always shaping them, challenging them, throwing up new obstacles. And fundamentally, that's why dinosaurs are so important to study. Like, yes, it's cool to study dinosaurs. It's an amazing thing to dig up dinosaur bones for a living. I love studying T-Rex.

You know, I mean, how can I not? These are awesome animals. And I think they are important because they do get kids especially, but also the public interested in science. They're a real gateway into science. But more than anything, dinosaurs are clues from the past that tell us how real organisms, real ecosystems changed over time, how they dealt with changing climates, changing environments.

The history of Earth is immense. Four and a half billion years of incredible change. Everything happening in today's world has happened before. Temperatures have spiked. There have been global warming events. Sea levels have risen. The oceans have gotten acidic. All these things levels have risen. The oceans have gotten acidic. All these things that happened before.

The causes now are different, but these things have happened before. If we want to understand these things, we need to look to the fossil record. Real plants and animals have already had to endure these things. And some have succumbed. Others have survived. Others have prospered. And so the early story of dinosaurs to me is a story of a humble group of organisms that survived, endured, and eventually prospered in the face of incredible obstacles. Looking to the sources.

I love the passion. And see, science and history, we're not too different after all. Steve, this has been a brilliant chat. Thank you so much for your time. Last but certainly not least, we mentioned it a couple of times of times but one more time your book on this topic is called it's called the rise and fall of the dinosaurs the book came out a few years ago it's an adult pop science trade type of book it's a narrative book it's not an encyclopedia it's not a kid's book it's for adults it's a story of the history of dinosaurs and how we study dinosaurs. But what's new now is we have this gorgeous new Folio Society edition. So this was a thrill for me. I'm a big bibliophile like many of

us who study science and study history and the Folio Society. They just do the most fantastic job of taking books and putting a new spin on them. So there's beautiful new artwork from one of the world's greatest paleo artists named Davide Bonadonna from Italy. We have a new cover. We have new interior spreads, including spreads of two of the most classic dinosaur ecosystems, a Jurassic ecosystem with all these big long neck dinosaurs, and then the latest Cretaceous ecosystem with T-Rex and Triceratops, the one that was there the day the asteroid hit. We have new maps in the book. We have a big pullout map showing the localities of important dinosaur discoveries. And we have lots of new images in the book. Beautiful, full color, full page images. And I think images like that, ultimately with dinosaurs, these are visual things.

We need to see them. We need to revel in them. My words on the page can do it a little bit, but really we need to see them in their glory. So this Folio Society edition, it is absolutely beautiful. I just got my copy sent here last week and I'm just mesmerized by the job they put into it and just incredibly honored to be part of their catalog. Well, Steve, as you say, it is a beautiful book with lots of lovely images and so much more. What it just goes for me to say, Steve, thank you so much for taking the time to come on the podcast today. Thank you very much, Tristan. My pleasure. And really fun to chat about not just dinosaurs, but this intersection between paleontology, history. And we're really all doing the same thing.

Well, there you go. There was Dr. Steve Brissetti explaining all about the rise of the dinosaurs. I hope you enjoyed that episode. It's slightly different to our usual sorts of episodes on the ancients. There's no Greece, there's no Rome, there's no other ancient civilizations in sight. But who doesn't love dinosaurs once in a while? And you can rest assured we'll be doing some more dinosaur content in the near future. You're going to love it.

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