The Ancients - Top Five Dinosaurs

Episode Date: September 25, 2022

They’re big. They’re fierce. And they’re extinct. This is how today’s guest - palaeontologist, evolutionary biologist and Senior Editor of the science journal Nature, Henry Gee, sums up why we have a continued fascination with dinosaurs.Join Tristan and Henry as they take a deep dive into their top five dinosaurs - from the Iguanodon to the Tyrannosaurus rex, plus a few surprises along the way.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!While you’re here, to be in with a chance of winning 5 Historical Non Fiction Books (with one being a signed copy of Dan Snow’s On This Day in History), please fill our this short survey so we can try and make your listening experience even better.

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 Entrance on History Hit. I'm Tristan Hughes, your host. And in today's podcast, where we're talking all about dinosaurs once more. And we've got a special guest returning to the podcast.

His name is Henry G. That name might ring a bell because Henry came on the podcast late last year to talk all about the origins of life on Earth, in which we covered millions, no, billions of years of history. It was wonderful to have Henry back on the podcast for this episode where we go through our top five dinosaurs. And we throw in a couple of surprises there too. It's always great having Henry on the show.

He's always full of energy, full of stories, full of anecdotes. So without further ado, to talk through our top five dinos, here's Henry. Henry, it is great to have you back on the podcast, my friend. It's wonderful to be back, Tristan. Thank you for inviting me again. You're more than welcome. We were talking just before we started recording that you are currently reading The Decline and Fall of the Roman Empire. We've had you on the podcast before to talk about the origins of life on Earth. It feels like we're going halfway with this very special pod today with the dinosaurs. Yes, it's good to get this historical continuity.

I remember when my son, aged very small, was at school in the kind of nursery section or the infancy. And they were taken to the local town museum to learn about the Victorians. And all the museum people were in Victorian dress and they learned about all sorts of things. So I didn't know this. So after school, I asked my kid, what did you do at school? Did you have a nice day at school? And usually you'd get oh i don't know don't remember but then he just launched into this long long story about how they'd been to the

museum and they learned about the victorians and the toys that victorian children played with and what they ate and what they did and you know i just sat back you know dinner and a show and then at the end he said dad were the victorians before or after the dinosaurs and so after that it became you know everything became sort of relative to victorians and dinosaurs so it'd be you know dinosaurs anglo-saxons tudors dinosaurs romans anglo-saxons victorians that sort of thing but then some wag said to me actually the dinosaurs came after the victorians because victorians invented the notion of dinosaurs it was a victorian scientist so i thought that would be a bit confusing to my tot at the time.

Well, actually, that is a well, actually moment, isn't it? Yeah. Clever clogs, clever clogs indeed. I mean, but, you know, whether it's the Victorians or whether it's us nowadays, Henry, there's just something about dinosaurs that fascinates each and every one of us. Yes, there is. I don't know what it is. I've tried to think a lot about that.

The usual glib answer is, well, they're big, fierce and extinct. So they're great, big, fierce, but they're conveniently extinct. So they're not going to come and eat you. But I remember seeing dinosaurs when I was the same age as my tot coming across Victorians. And it was their hugeness that got me when age five I was taken to the Natural History Museum and with not really much of an idea about dinosaurs. They were just so jaw-droppingly big. And that's really what got me. But it's a legitimate question why dinosaurs, rather than any other kind of prehistoric creature, excites this kind of fascination in people. There's a very, very good book called Dynomania by a man called Borea Sachs,

who tries to analyze this. And it's done in terms of national consciousness that dinosaurs, you know, in the Victorian times were seen as a kind of very British thing. They were part of imperial greatness, and so we took dinosaurs to our bosom. And in America, they were discovered just as the West was opening up, so it was seen as big, grand, American, manifest destiny, pioneer spirit. So it's a good thesis, but why it is that dinosaurs excite small children, that's really quite interesting how most small children can name 10 different dinosaurs before

they're potty trained, rather than any other creature is something I mean, it's a good question. Why is it that they excite so much interest? Well, my friend, don't worry. We're not going to name 10, but we are going to name five or six in today's podcast. We've had a bit of a chat today before recording. We had a bit of a back and forth about our top five dinosaurs and drawing a list together, which we're going to talk about over the next 40 minutes or so.

And Henry, looking through the list, I'm not going to spoil anything, but I think we or so and Henry looking through the list I'm not going to spoil anything but I think we've got we've got a nice balance between some very well known but also a couple of lesser well-known dinos too. Yep we certainly have there are a lot of different kinds of dinosaurs and we'll be talking about the the good old-fashioned ones that everybody knows about but you know over the past 20 30 years quite a lot of new dinosaurs have been well new dinosaurs they were there all the time your dinosaurs have been discovered that people might be less familiar with but which are still very exciting well i'll say them out

now we've got iguanodon diplodocus triceratops t T. rex, and S. spinosaurus aegiapticus. Now, Henry, which one would you like to start with? Let's start with Iguanodon. That was on the list, wasn't it? Absolutely. Because Iguanodon was one of the first ones to be discovered, and that was a British discovery. In fact, it was a discovery from quite close to where I grew up in Sussex, in the wheels of Sussex, in the sandstone. It was discovered by the wife of a country doctor, Mrs Gideon Mantell, and they were clip-clopping along, this is the story, in their pony and trap and Dr Mantell went to visit a patient. Well Mrs Mantell was just looking around outside and discovered the first remains of what became Iguanodon and

I've got another anecdote actually also related to small children. A friend of mine, a school teacher from near where I grew up in Sus sussex he told a story about going to visit the sandstone quarry with his small class of children where iguanodon was found and to get to this sandstone quarry they had to go through a path through the woods and they had to go through an immense five barred gate which if you're five, is really big. And then they got to the quarry, and the quarryman was talking to them about how Iguanodon was found. And a little boy at the back said, please, sir, how did it get through the gate? So that's another story about Iguanodon. Yeah, absolutely. And that's a great discovery story, isn't it? Gideon Mantell, but his wife,

Mary Mantell, who makes the discovery. What exactly is an iguanodon? Iguanodon was a moderately sized dinosaur. I don't know, about 30 feet long-ish. I'm not quite sure. It was a vegetarian. It was mostly bipedal, but it could walk on all four legs if it wanted to. And it belonged to a group of dinosaurs that were vegetarians and they had immense amounts of teeth in their jaws they had huge batteries of grinding teeth to grind up the very tough vegetation that lived at the time and they were pretty much defenseless except on their thumbs their thumbs had this immense spike which would have been good if they were hitchhiking but it was evolved before cars and they wouldn't be able to get in anyway so you could have seen it as a pre-adaptation to immense spike which would have been good if they were hitchhiking but it was evolved before cars

and they wouldn't be able to get in anyway so you could have seen it as a pre-adaptation to hitchhiking but i suppose if any predatory dinosaur came too close they could just shove this up its nose when iguanodon was first reconstructed it was reconstructed very much as a four square quadruped with the horn on the end of its nose because the iguanodon was found in Sussex you know in the early Victorian times but then much better remains were found in a coal mine in Belgium whole skeletons were later found and then people got a much better idea of the anatomy and that this spike was on its thumb and so on. So it became a fairly well-known dinosaur, particularly after the discovery in Belgium. And of course, people

had no idea what dinosaurs were because nobody thought about it. But this Eguanodon and two other ones, Megalosaurus, which is a predatory dinosaur is another one called hydeosaurus were described by richard owen the great victorian anatomist and it was he who came up with the word dinosaur terrible lizard they look kind of reptilian but they were a different kind of reptile from anything that had ever been seen before and remember remember, this was all before evolution. This was all before Darwin. But it took the discovery of dinosaurs to make people realise that the world was much older than the biblical accounts would suggest.

And this was another idea that was very difficult to stomach back then, the idea of extinction, that animals had become extinct. Maybe they perished in Noah's flood. In fact, it was this idea of extinction that actually opened up the American West. You may know that Thomas Jefferson, president, the villain in Hamilton, and, you know, celebrity slave owner and proto scientist, he commissioned Lewis and Clark to go and explore North America, but he hoped they'd find living woolly mammoths. He was sad that mammoths were not found anymore, and he hoped they'd find some live ones west of the Mississippi. Jefferson had actually

described a fossil, Megalonyx, which was not a dinosaur, but a giant ground sloth. And I've actually seen the fossil that Jefferson described in Philadelphia. described a fossil, Megalonyx, which was not a dinosaur but a giant ground sloth. And I've actually seen the fossil that Jefferson described in Philadelphia. In the American West later on, people found lots of dinosaurs, but sadly no live mammoths, which is a bit sad, really. So the dinosaurs helped open up the vista of the past, of the ancient, deep ancient past, to people who had no idea that such a thing existed before then people had found dinosaur bones and thought they were the bones of giants

so the iguanodon is significant in the fact it's one of those first fossils discovered as you say henry i mean this might be a personal bias of mine because i'm slightly related to gideon and mary mantel which i take pride in well even more see, I grew up in the Ashdown Forest in there, and you're related to the Mantel. So in our different ways, we are fans of Iguanodon. Absolutely. We are friends of Iguanodon. And also, as I said, this might be the personal bias coming in. But if they existed, and I'm not an expert in this, so if I'm wrong, please correct me.

But if Iguanodons exist in the Jurassic, maybe in the cretaceous too over like large parts of the planet they do feel like one of if not the most successful plant-eating dinosaur that the world ever saw yes the kind of body form of the iguanodon the kind of medium-sized mostly bipedal but sometimes quadrupedal dinosaur with the jaws absolutely crammed full of grinding teeth. Iguanodon was kind of an early example, but they became very successful as the age of dinosaurs wore on and largely took over the role of herbivorous dinosaurs from the gigantic sauropods like Diplodocus or Brachiosaurus.

The so-called Hadrosaurs, which Iguanodon was one, they became the more predominant herbivores. And they lived in immense numbers, huge herds of them. They were very kind of successful creatures. Well, let's move on then. We've got to get through these next four. And you mentioned the next one on our list right then. Let's go on to the Diplodocus diplodocus now this is a massive massive creature

isn't it yeah i can't remember how big it is but there was one in the natural history museum people remember dippy the diplodocus in the foyer of the natural history museum in london taking up the whole hall it wasn't the heaviest of them, but it was very long. It was one of the longest ones with a very long neck and a very long tail. When I was a lad, Dippy's tail trailed along the ground. But when people got to know more about the anatomy of the dinosaurs, people realised that the tail was held quite high above the ground and would whip around and could probably whip some marauding allosaurus around the gob if it got too close. And there have been various ideas about how fast the tail could have gone,

could it have gone, you know, the speed of sound, so on. But I think the real reason why they moved the tail bones above the floor was because when the tails were on the floor, the little bones kept being nicked by little boys who used to pinch them and the the actual skeleton in the natural history museum was actually a plaster cast of one in america diplodocus carnegie named after the robber baron and scientific philanthropist andrew carnegie so it was a plaster cast and they had loads and loads of cast tail bones in a big box in the paleontology department to replace ones that had been pinched by small

boys. Just between you and me, that's our little secret. I think that's the real reason they put the tail above the floor. Well, let's jump into the dinosaur itself, Henry, because the age of the sauropods, of creatures like Diplodocus, when was that? What do we know about when and how Diplodocus lived? The heyday of the sauropods was in the middle of the Jurassic period, which ended between about 200 and 150 million years ago. And a lot of the great sauropods were found in a huge sequence of rocks called the Morrison Formation, not named after the supermarkets, but it's in the American West. And this brings us to another great episode in dinosaur discovery. When the American West was opening up, pioneers kept finding these huge bones,

and two particular scientists on the East Coast were interested in them. There was Othniel Charles Marsh, who was a bit of a dimwit, but he had a very rich uncle called Peabody. Uncle Peabody opened his Neville Museum, which is now the Peabody Museum at Yale. And then there was the extremely bright and ambitious Edward Drinker Cope, who was the Harvard man. And these two people would commission gangs of workmen to go into the American West to dig up the bones and send them by pack, mule, rail, head, whatever, back to the East Coast.

And searching for fossils and digging up dinosaurs is quite heavy work anyway but just think they were far from civilization and they were often slaughtered by the apaches and they had quite a lot of dangerous adventures but the biggest enemy of any dinosaur hunter in the American West was other dinosaur hunters working for either Marsh or Cope or the one you weren't working for. And there's a wonderful memoir by a man called Charles Sternberg, who was one of the dinosaur hunters, I can't remember for which one, and he talks about what it was actually like to go and hunt for dinosaurs on the frontier. It was really quite exciting. And so how do these dinosaur hunters, how do they,

what do they therefore reveal about the Diplodocus, about, you know, how they lived, about when they lived, and like that kind of environment which these giant creatures were living in? Well, of course, now when you look at the American West, it's quite dry and desiccated badlands. But back in the time of the dinosaurs, most of the continents of the Earth were still more or less welded together in one giant continent, Pangaea. Pangaea came together much earlier than that. In fact, towards the end of the dinosaurs, it was starting to break up. But back in those days, the Earth was one large continent, and a lot of it was very, very hot.

There were some very hot deserts, but a lot of the places where the dinosaurs lived were very lush, very hot. There were some very hot deserts, but a lot of the places where the dinosaurs lived were very lush, very watered. There was no polar ice on Earth during the whole realm of the dinosaurs. The climate was pretty equable from pole to pole. In fact, there were dinosaurs known from Antarctica. Antarctica wasn't over the South Pole then but it was pretty far south and there are dinosaurs known from Alaska now even though these polar places didn't have any ice on and they were quite warm

they still got dark for half the year so the existence of dinosaurs particularly in Alaska suggests that they were much more active creatures than you know lizards and snakes and it was part of the realization that dinosaurs are more than just reptiles. They were very active, warm-blooded, intelligent creatures, as well as being big and fierce.

With the Dibridocus, one of the things that we know sauropods were is absolutely huge. And people are interested to know how they got so big and the reason they got so big is because inside they were made like birds so really it's best not to think of a diplodocus as a giant reptile but as a giant featherless four-footed flightless bird because inside birds birds have a unique way of breathing and it's been found in some living reptiles too and also has been seen in the way dinosaur bones are made when birds breathe in the air doesn't immediately come out again it goes into a lot of air sacs that permeate the entire body

and you can find this now if you pick up a chicken not a frozen chicken but an actual feathery chicken you know you'd expect from its size to be quite heavy, but it's not. And the reason is, is it's absolutely full of air. These air sacs permeate the entire body, including even into the bones. I mean, bird bones are hollow, and so are dinosaur bones. And one of the big air sacs that is important in the body of a bird and a dinosaur is it goes next to the liver now the liver is the i'm sorry about this digression but it explains why dinosaurs are huge the liver is the internal organ that generates most of the heat because that's where all the

food goes that's where all the digestion happens that's a big kind of smokestack industry of the body it's the big chemical factory and it produces a lot of heat and that heat has to go somewhere now in mammals like us it's carried away by the bloodstream and eventually comes out in your breath but in dinosaurs it was right against one of these big air sacs and it came directly out of the lungs without having to go into the blood and then go through the blood to the lungs and come out of the lungs again and because of that dinosaurs could grow very very large because the thing that limits the size that things can grow is heat exchange it's all to do with volume and surface area the larger you get the more insides you have relative to your outsides i mean if you're a

tiny animal the size of a dot, you don't need any special means of shedding heat because there isn't much inside. You're all outsides. But as you get bigger, there's more and more insides, and the insides are further and further from the outside. So any heat generated inside has to travel a long way. And so if you get more than a certain amount of size,

more than the size of a dot, you have to have special mechanisms to move the heat. Otherwise, you'll boil yourself alive from the inside. So dinosaurs could get as big as they did because they could transfer heat by this efficient system without boiling themselves alive from the inside out. And that's how dinosaurs could grow so immensely big. inside out. And that's how dinosaurs could grow so immensely big. And of course, dinosaurs grew big, especially these large herbivorous dinosaurs, because they were being chased by large carnivorous dinosaurs. And the only defense one of these large sauropods had, they didn't have any armor, they couldn't run fast. The only defense they had was just being enormous and also being sociable they lived in very large herds they nested in huge rookeries which would have stretched from

horizon to horizon they were so big and there's some evidence from trackways that the large dinosaurs when they're on the move used to form a ring around the smaller and younger dinosaurs in size so that's how they would move and so it was just the sheer size that was their defense interesting how interesting and as you said earlier then that size decreases as the time goes on and you get the likes of the hadrosaurs and iguanodon taking over don't you yes but you know when we say they were smaller they were were still very large. Yeah. And they lived in very large numbers, so safety would have been in numbers. Hi there, I'm Don Wildman, the host of the brand new podcast, American History Hit. Join me twice a week as I explore the past to help us understand the United States today.

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All right. Well, let's keep moving on this top five i said we've only got limited time but henry i want you to take it away i want you to go wild you have like five or ten minutes to explain this next dino tell me why triceratops is the next one on our list triceratops actually i suggested this triceratops is my wife's favorite dinosaur penny this is your favorite dinosaur triceratops was a member of another group of dinosaurs the keratopsians i'm pronouncing my c you know classically approved way there they were distinguished by a lot of armor on the head they had a big neck frill extended from the back of the skull to protect the neck. They had various horns on their faces. They were herbivorous dinosaurs. They had a lot of teeth, quite hadrosaur-like, but they also had a very long horny beak, which they would crop

the vegetation with. They started off quite small and bipedal, which in fact a lot of dinosaurs started out, but quite soon they became very big and very quadrupedal the triceratops we're all familiar with there were several different sorts and they lived in western north america in the very end of the period of the dinosaurs in the late cretaceous from 90 million years to when they died out 65 million years ago they're mostly known from western north america but they're mostly known from western north america but they're also known from eastern asia which was joined up at the time but they're also little bits of them everywhere you know there's one that turned up in hungary of all places

but the triceratops we all know about lived in the wild wild west lived in the wild west indeed and it has some defining features all around its horns isn't it uh yeah there are triceratops there was pentaceratops there were all kinds and there were all various different species and the reason why they had all these horns it could have been so the species could tell each other apart they might have been to do with sexual dimorphism like birds display with their feathers. There's some amazing artist reconstructions that the frills were decorated with all kinds of patterns that could either be warning coloration or to display. But like all dinosaurs, they live busy social lives, and Triceratops would have been no exception to that. And so what do we know, therefore,

are there any other key things you'd like to highlight about the Triceratops, about this particular species? For instance, in how it lived, its great enemies, or do we know anything about movements of these creatures, how they interacted with the wider dinosaur, late Cretaceous world? Well, you've given me the perfect segue to come into everyone's favourite dinosaur. T triceratops's big enemy was tyrannosaurus rex the king of the tyrant lizards which was the acme of carnivorous dinosaurs this creature weighed five tons and it could be 40 feet long and it only had these tiny arms but it had these immense muscular pillars of back legs counterweighted with a long tail and the counterweight was important because a lot of

the mass was in its chest and its huge huge head which was full of teeth absolutely full of teeth each one the size and shape of a banana but with the consistency of carbon steel and powered by huge muscles and the bite of a t-rex was probably unequaled by any animal certainly land animal before or since it could crush bone it would take huge chunks out of anything it ate and swallow them whole. And we know this because people have found T. rex poo. It fossilises because it's mostly bone. And the bone is Triceratops and other armoured dinosaurs like Ankylosaurus. and other armored dinosaurs like Ankylosaurus. But there are also known fossils of Triceratops with puncture marks in its frill

that absolutely fit T-Rex teeth. So T-Rex and Triceratops had this arms race. T-Rex could literally crush bone as it bit. And Triceratops had all this bone that could be crushed and still walk away without damage. And of course, there are quite a lot of famous and rather dramatic artistic reconstructions. The horns of a Triceratops could puncture the soft underbelly of a T. rex. So they would give as good as they got. But of course, it's very romantic to imagine battles

between T-Rex and Triceratops, but not inconceivable. When you see T-Rex battling with a Stegosaurus, no, no, no, no, no. The Stegosaurus had died out hundreds of millions of years before. But T-Rex and Triceratops were found in the same places, the same ages in Western North Americaica i remember i once saw a cartoon called the adolescent almighty and in this cartoon it's single panel this panoramic view was under a lowering sky a t-rex and a triceratops were giving battle and this little speech balloon

comes from the sky saying cool i mean it's so fascinating i love how you mentioned that arms race almost in the evolution of these two creatures and you know how they were almost the predator versus the prey but the prey also had the ability to fight back and i think on a slight tangent let's also talk about that other key animal reptile dinosaur which you mentioned there alongside triceratops which was sometimes on the opposite end of a tyrannosaurus rex which is these ankylosauruses yes the ankylosauruses were kind of the end point of another group of dinosaurs these armored dinosaurs their relatives the stegosauruses started it in the Jurassic. These were slow-moving, four-footed vegetarians,

and the Stegosauruses had these huge bony plates sticking up in a double row out of its back and spikes at the end of its tail. And there are various kinds of Stegosaurus. The archetypal one is, again, from the Morrison Formation in Western North America. But they've been found in Africa. They've been found in China.

They're a very successful group. But cousins of theirs developed into a much heavier armored creature with flat plates all over it, more like a giant armadillo. Flat plates all over the body, the legs, the head, with a big club at the end of the tail and i suspect what they could do if they were attacked was basically hunker down on the ground like a kind of armored pillbox and just wait till the predator had got bored of trying to get in and then they would go away but they were covered absolutely covered in thick armor plates and they lived at the time of t-rex and

its relatives the kind of acne of predatory creatures to focus on that club a bit more because it's interesting what you mentioned your theories is this like well-armed medieval knights you know almost impenetrable if it was tucked down you know for a tyrannosaurus even with its jaws of its teeth to dig its teeth into but that club that offensive part of an ankylosaurus's anatomy it is really extraordinary isn't it when you see visual depictions of this weapon that was at the end of a tale of an ankylosaurus yes now of course one reason it could have been used as a defence against predation, but another idea was that it was used in sexual display. I mean, I've got no evidence for or against,

but I would suspect that that would have been of use for them in the same way that you see stags attacking each other with their antlers, giraffes walloping their necks against each other. I think males would basically wallop each other with their antlers, giraffes walloping their necks against each other. I think males would basically wallop each other with their clubs and see if they could do damage to each other until one of them wandered off. So I think a lot of these offensive structures could have been used in display between ankylosauruses. There was an early relative, actually it's not an early relative,

it lived at about the same time, Pachycephalosaurus the bone-headed dinosaurs these were bipeds but they had very very thick skulls it looked like they're wearing cycle helmets and they were many inches thick and the idea is that the males would run at each other and back each other in the head and then see which one fell over first. And these were relations of triceratops, another theme on the armoured dinosaur riff, as it were. The cycle helmet dinosaurs, right? Yeah. Pachycephalosaurus. Okay, well, let's go back to Tinosaurus Rex just quickly. One more question on that, Henry. The acme of the predator, that's perhaps the most famous dinosaur we know of today.

We've mentioned other dinosaurs, Triceratops, Diplodocus and Iguanodon, they're living in herds in big groups. Is it very different with T-Rexes? Yes, it would have been because carnivores are the top of the food chain and the ecology only supports a certain amount of carnivores. It's the whole big fierce animals are rare thing because herbivores eat lots of plants and they convert only a certain amount of plant material into herbivore and so carnivores eat the herbivores but it takes quite a lot of herbivores to support a carnivore so t-rex like many carnivores wouldn't have lived in enormous herds it might have lived in family groups like prides of lions or similar things,

or have been solitary. Nobody knows, but we do know that all the dinosaurs we know about that lived in large herds were the big herbivores. The hadrosaurs, the sauropods, they lived in big groups. They nested together and they moved together. And it would have been very much like documentaries of the Serengeti. You'd have enormous groups of dinosaurs, maybe several different species moving in herds,

with large carnivores snapping away at the outside, and maybe smaller carnivores, the kind of little raptors, nipping away as well. But the carnivores would have been much rarer. Having said that, there have been quite a lot of these skeletons found t-rex seems to be quite popular i don't know how many have been found certainly not hundreds but quite a few now well one last question because we've got quite a lot of evidence for the t-rex therefore from the fossils and so on do we have any idea and if

we don't absolutely no problem do we have any any idea whether the females were bigger than the males? Do we have any idea around that? There probably is, but I'm not conversant with it immediately. I don't have that to hand. But I do know that there's a lot of evidence, and it's from T. rex, to show that dinosaurs reproduce like birds, in the sense that you can tell the sex of a t-rex from the insides of its bones because the females would strip the insides of their bones of calcium to make eggshells with and this is something that birds do now and you know i think it's likely the females would have been bigger than the males this is generally true of creatures like this but it's another bird-like thing dinosaurs laid eggs all dinosaurs laid eggs there's no dinosaur that we know about gave birth to live young so even the

biggest dinosaurs laid eggs and t-rex would have laid eggs and the female dinosaurs would have used calcium from inside their own bones to reprocess into eggshells right how interesting well i love that you mentioned that potential idea there which we will go back to in due course in our second podcast about feather dinosaurs and the like because that seems a little hint there doesn't it henry but we talked about the ankylosaurus but that was a special extra dino to our list because we got one more and i know that this is a personal favorite of yours and this is a more unusual one but it is a very interesting one i want you to take it away henry and correct me if i say this wrong spinosaurus egiapticus well you're the

classicist egyptiacus anyway in egypt before the Second World War and probably before the First World War, I can't quite remember, this remarkable giant carnivorous dinosaur, Spinosaurus, was found. It was very, very poorly known. It was probably taller and longer than T-Rex. Probably not as massive. I mean, T-Rex was a bit of a thick boy a bit of a chunk t-rex but the thing about spinosaurus it had these long long long jaws like it's a long crocodile like jaws which is the sort of jaws you'd see in a fish eater all the animals you see that are specialized as fish eaters tend to have very long long jaws with teeth in them and spinosaurus was one of them another thing

spinosaurus had was it had big claws on its hind feet. But Spinosaurus was kind of shadowy because the original remains were destroyed in the war. I can't remember if it was the first war, I think it was the Second World War. And later on, other ones were discovered. Now, one of the close relatives of Spinosaurus is a creature called Baryonyx that was discovered in England by a dog walker called Mr Walker who discovered this immense claw so it's called Baryonyx walkeri named after Mr Walker and his dog who found it while walking the dog so you know if you keep your eyes open while walking your dog who knows what you can find but this creature baryonyx was a big slender tall rangy creature with long jaws full of teeth and other ones have been found of this general

pattern and later on in egypt there's some new research done by egyptian researchers that have unearthed more spinosaurus remains now. Now, Spinosaurus is, at the moment, one of the most controversial dinosaurs because there's a great deal of debate about how it lived. Now, it's thought that Spinosaurus and its relatives were fish eaters, and there's kind of good evidence for this. They had fish hanging around, and they lived on the coastline, and, you you know animals with

this kind of jaw tend to eat fish it's a kind of trope but the general view of spinosaurus was that it had these long hind legs and fairly small front legs like carnivorous dinosaurs tend to but there was a reconstruction of spinosaurus in which the legs were of much more equal sizes and it would have been reconstructed as a swimming animal doing a kind of doggy paddle. And that caused an absolute furore. People couldn't believe this. There was a great deal of resistance to the idea that Spinosaurus, or any kind of dinosaur, was very much of a swimmer in the sense that it did any more than paddling, because the sea at the time was absolutely full of gigantic, ferocious marine reptiles.

There was no scope for any more. I mean, there were the mosasaurs, these giant lizards. There were the ichthyosaurs, these giant reptiles that look like dolphins. And then there were the plesiosaurs and elasmosaurs and goodness knows how many others. The world was full of sea serpents. It was just crammed full of them. So there would have been no room in the sea for dinosaurs,

which were a land-living group, to have invaded. So this reconstruction of Spinosaurus as this kind of four-legged dog paddler caused a great deal of furore. And then these Egyptians researchers discovered something that hadn't been found, or at least not in any detail. They found the tail of one, long, long, long tail, which is very deep from top to bottom, incredibly deep, which suggested it would move from side to side like a swimming animal. And then some other researchers, maybe some of the same ones, they got together and they looked at the bone density of Spinosaurus.

Now, a good clue for a land animal that's adapted for water is having very dense bones that help contract the buoyancy. Because, of course, you know, dinosaurs are full of air. They would keep bobbing to the surface. It was no point them holding their breath because they were full of air. They would have been lousy. They would have just kept popping up like corks i mean even people and we're much less full of air than dinosaurs you know we're less dense and water and it's difficult to stay underwater so but if you look at a lot of animals that are secondarily aquatic that means they're land animals but have been evolved to be aquatic things like dugongs and manatees, they have very dense bones that would have allowed them to contract their neutral buoyancy and actually go deep underwater.

And lo and behold, Spinosaurus has kind of dense bones, just like you'd expect for a land-living animal that spent more time in the water than you would normally expect. So it seems that Spinosaurus was, at least some of the time, a much more aquatic dinosaur, something that has never been seen in the whole of the amazing panoply of dinosaur wonderfulness, is these aquatic fish-eating carnivorous dinosaurs. How interesting. This almost feels, therefore, Henry, that potentially they might find more dinosaurs like this in the future if this new unique function of a Spinosaurus continues to be validated in the years ahead. Well, you'd think so, given that fossils tend to happen underwater and most fossilization tends to happen in lakes or near the sea.

But who knows? There are still lots more amazing dinosaurs being discovered. I mean, we've talked about the first ones being found in England and the great heyday of dinosaur discovery in North America. But now there are dinosaurs being discovered everywhere. There's huge deposits in China, especially China, Argentina, Madagascar. There's some dinosaurs that have been published recently in Zimbabwe. So basically, they're pretty much everywhere you look.

Oh, Mongolia. Oh, my goodness. Mongolia. Yeah, locked in there. So I wouldn't be surprised to find even more eye-poppingly amazing dinosaurs to turn up any day. Well, Henry, this has been great. Last thing, very quickly,

any other special mention dinosaurs you'd like to say before we wrap up this episode? Oh, gosh, I don't know. There are just so many. I think all my other favourite ones are feathered dinosaurs, but we're not going to talk about those now, are we, Tristan? We're not going to talk about feathered dinosaurs. I'm going to give a shout out to the brachiosaurus because that's such a cool iconic one isn't it yeah yeah brachiosaurus or now it's called giraffe titan

apparently is it yeah they apparently changed its name i hope they asked it first yeah that was one of the brachiosaurus arm lizard because its front legs were longer than its back legs so it could get its head even further above the ground it was certainly the tallest dinosaur a brachiosaurus oh argentinosaurus the very biggest dinosaur ever known 70 tons of dinosaur 100 feet long lived in the early cretaceous in south america and it was preyed by gigantic carnivorous dinosaurs carcharodontosaurus and land shock possibly even bigger and fiercer than the t-rex so that's all fairly recently found in south america another whole ecosystem of gigantic predator gigantic prey each one evolving to be bigger.

Well, I mean, that's the thing, because normally we think of the T-Rex as like the Titan, the big, big one. But there are others like Carnotaurus and the one you just mentioned there, which I'm not going to try and repeat the name of. There are other incredibly huge meat-eating dinosaurs too. It's just the T-Rex is the one we always think of. Well, yes, but I think the T-Rex will always be special because I think it wasn't just the size, it was its build and its bone-crushing force. I mean, it would have been utterly terrifying. People have wondered whether it could run fast, but I don't think that really matters because with the stride length it had, it would have easily caught up with you, even if it was running slowly. It's a terrifying thought, Henry, to leave this episode on. This has been great.

Last but certainly not least, your book, which covers this and so much more, is called... It's called A Very Short History of Life on Earth, Tristan, and it is in the proverbial All Good Bookshops, and now in paperback, believe it or not. So if you are a beginning zoology student, it will do half your homework for you, so you should buy two. And a friend of mine, Mrs K P of Jersey, said that's Christmas

sorted out then, so remember that rectangular gifts are easier to wrap. So there you are. Absolutely. And if you want some Tyrannosaurus Rex inspiration for Halloween, you also know where to go to. Oh, yes. And it's out now, folks. Out now, indeed. Well, Henry, it just goes to me to say thank you so much for taking the time to come back on the podcast today. You're very welcome. I've enjoyed it as ever.

Well, there you go. There was Henry G talking through our top dinosaur choices. I hope you enjoyed this slightly different, very, very conversational, very relaxed episode. Now, last things from me, we have a special offer currently ongoing at History Hit. History Hit is our online, on-demand history channel. We've got documentaries from the 20th century all the way back to ancient history and prehistory you can guess i'm much more of a fan of the latin i present a few documentaries there too you can also get access to all of our podcasts from the ancients to god medieval not just the tudors betwixt and so on the whole history hit stable you can get access to all

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