Season 4 Episode 2: Transcript Dinosaurs in Antarctica

Alok Jha: Let me take you on a journey. To the coldest place on earth, and its last and greatest wilderness. On a voyage to Antarctica…

Hello and welcome back to A Voyage to Antarctica, brought to you by the UK Antarctic Heritage Trust. I’m Alok Jha. 

This week, we’re voyaging further than we’ve ever done before; 100 million years back in time… to when Antarctica was a rainforest and home to some of the biggest creatures to ever walk the earth – the dinosaurs! 

Taking us on this journey is Dr Susannah Maidment, Principal Researcher in fossil reptiles at Natural History Museum in London. 

Susannah has a PhD in vertebrate palaeontology from the University of Cambridge, and before working at the Natural History Museum, was a Research Fellow at Imperial College London. She also spent two years working in industry as an exploration geologist.

Susannah’s work focuses on the origin and establishment of dinosaur-dominated ecosystems using techniques ranging from taxonomy to biomechanics and sedimentology. She has published more than 65 papers in the peer-reviewed literature, and currently supervises six PhD students. 

Susannah appears regularly in the media talking about dinosaurs, and has been a guest on BBC Radio 4’s The Life Scientific and The Infinite Monkey Cage. She was one of National Geographic UK’s Women of Impact in 2019.  

Alok Jha: So our podcast series is about Antarctica, and it's famously a very cold, icy, inhospitable place. It kind of wasn't always like that, was it? Especially from your point of view. So tell us about a time when the landscape was a bit different.

Dr Susannah Maidment: Yeah, that's right. Antarctica wasn't actually permanently glaciated until about 30 million years ago. 

The Mesozoic is the time period when the dinosaurs dominated the Earth, it was from about 250 million years ago to 66 million years ago, and it comprises the Triassic period, the Jurassic period, and the Cretaceous period. And during the Jurassic and the Cretaceous, actually, all animals larger than a meter in size that lived on land were dinosaurs.

So, back in the Mesozoic there was no permanent ice caps on Antarctica at all. And actually there's quite a lot of evidence that there was quite a lush forest on Antarctica during that time period.

Alok Jha: So what kind of lush forest are we talking about? Is it like some sort of scrubland? Is it rainforest? What was the sort of climate like at the time? 

Dr Susannah Maidment: Yeah. Well, I mean, it varied a lot during that time period. Obviously that's an enormous amount of time. During that time, flowering plants evolved. So they evolved in the Cretaceous.

So back in the Permian, we have fossils from Antarctica of Glossopteris, which are tree-like ferns that are known from all around the margins of the Southern continents. And they're actually part of the evidence that all of the Southern continents were once joined up to each other. And then obviously as we go through the Mesozoic.

We have flowering plants evolving in the Cretaceous and then we start to see some broad-leaved plants as well. 

 

Alok Jha: And how does that compare to the rest of the world? You talked about continents all being joined together, but what was the rest of the world like? Was there a part of it which was icy that was just somewhere else or was the whole planet like this?

Dr Susannah Maidment: There was a landmass called Pangaea during the early part of the Mesozoic, so from the Permian through the Mesozoic, that extended from effectively the South Pole to the North Pole. So Antarctica was a little bit further north than it is today. 

All of the continents were joined up into this single supercontinent called Pangaea. And then during the Mesozoic, these continents began to break up and that affected climate, of course, it affected ocean currents, which have a huge influence on our climate. And this also affected the evolution of the animals that were living on those continents. So lots and lots of changes during the Mesozoic, and at the end of that time period, we start to see a planet that we'd recognize today with the continents, you know, distributed much more similarly to the way they are today.

Alok Jha: And what's exciting about this particular time is that the landmass beneath Antarctica being so lush and green and vibrant is that there were dinosaurs roaming around at the time as well. Again, it's a long time period, so I guess there's many answers to this question, but what kinds of dinosaurs would have seen in that time?

Dr Susannah Maidment: As you might expect, we actually don't have a brilliant fossil record from Antarctica. 

Alok Jha: Yeah, I was going to ask you about how you know all this stuff, but what do you imagine at least? 

Dr Susannah Maidment: We do actually have dinosaurs from two periods in time from Antarctica. One is from the early Jurassic, and this is really when the dinosaurs are just getting going.

So they're from about 198 million years ago, something like that. And we've got a meat-eating dinosaur called Cryolophosaurus. We've also got an early sauropodomorph, which is a long neck, long tailed dinosaur called Glacialisaurus. So these kind of icy names invoking where they're found. These are known from the Transantarctic Mountains.

And then if we move forward in time to the end of the Cretaceous period around about 68, 70 million years ago, something like that, we've got more dinosaurs from Antarctica, and these are known from the area around James Ross Island and the Weddell Sea. 

We've got meat eating dinosaurs, quite closely related to birds. We've got ornithopods, which are small herbivorous dinosaurs. And we've also got an ankylosaur, which is an armored dinosaur. And these were living alongside things like pterosaurs that we have also in these deposits, which are the flying reptiles. And they're actually found in shallow marine rocks. So these dinosaurs are being washed out into the sea and being preserved there.

And so they're found in association with a whole bunch of marine animals as well. 

Alok Jha: And are these dinosaurs you've described specimens that people would know? You mentioned the pterosaurs, of course, people might be familiar with those, they're the animals, as you say, but the one you mentioned right at the beginning, the Cryolophosaurus, which I'm not sure if you've made up as a name. It sounds too neat. What does that look like? Is it something we recognize? 

Dr Susannah Maidment: Yeah, it's definitely something that you'd recognize as a meat eating dinosaur. It's a two-legged animal. It's got sharp pointy teeth and a kind of boxy skull. But Cryolophosaurus is interesting because it has a kind of crest on its head that sort of sticks upwards from behind its eye region. And we don't really know what the function of these sorts of things. We've got lots of dinosaurs that have kind of bizarre crests and horns, strange things on their bodies, and we don't really know what they were for. 

Alok Jha: Okay, some sort of display or something, I guess?

Dr Susannah Maidment: Yeah, I think that's probably most likely that they could have been some sort of display structure or supported soft tissues, which might have, you know, extended even further out from the body and been even more elaborate display structures.

Alok Jha: I mean, it sounds like it was quite a lively place in terms of plant and animal life, very rich in all sorts of species. 

Dr Susannah Maidment: Yeah, absolutely. And as I say, we’re really only scratching the surface of the fossil record. I mean, only a fraction of the animals that ever live in a place are preserved. You know, we've got to be able to find them, even if they are preserved.

You know, we don't always find them. And in Antarctica, there's a whole range of reasons why it's really difficult to find fossils. So yeah, we've really only scratched the surface of what might have been living there. 

Alok Jha: Well, let's talk about that. So how do you go about finding fossils in Antarctica, given the kilometers of of ice that now sit on it and have been sitting on it for millions of years?

Dr Susannah Maidment: Firstly, I should say I have never been to Antarctica to find fossils. If anybody would like to fund me to do so, I'd be very, very happy to go. 

Alok Jha: This is your route onto it. 

Dr Susannah Maidment: As I say, the ones from the late Cretaceous are found from James Ross Island and found from the coastline. So I guess that, you know, certain times of the year that's not permanently covered in ice that there are exposed rock there.

The descriptions of these dinosaurs when they're found are that they're extremely frost shattered. So they're often, you know, broken into bits and they have to be kind of stuck back together in the lab once they're excavated. So they're quite difficult to get out. And I guess it's the same in the transAntarctic mountains. I guess that, you know, there are times when We don't have permanent ice sheets across the whole of the continent and, you know, there are drier areas where there isn't the ice and you can actually find exposed rock there. 

Alok Jha: So you're waiting for the weather patterns to change so the ice sheets recede a bit or allow you to get to the land underneath in order to maybe opportunistically find where the fossils are sort of lying there.

Yeah, absolutely. And some of the dinosaurs that have been found are generally found completely opportunistically. We have a dinosaur here in the Natural History Museum's collections. It's a ornithopod from James Ross Island. It was discovered when someone was looking for ammonites.

So they're actually looking for marine fossils and they found the bones of this dinosaur. Totally opportunistic. And to be honest, that's how we find most dinosaurs. 

We're currently describing it, which means we are writing about its anatomy so that other people can compare it to dinosaurs that they found. And also we're going to give it a name. At the moment, it hasn't got a name in the literature, but we think it's a valid species, a new species, and we're going to give it a name.

Alok Jha: What are the candidates for the name? This is very exciting. 

Dr Susannah Maidment: Oh, I'm not telling you. It's under wraps until the paper comes out. 

Alok Jha: When's that? I'm going to look out for this. It's interesting you should ask that because this paper has been in the making since actually I was at secondary school, actually before I was at secondary school.

It's been a slow, slow progress on this paper, but we are now trying to finish it. Uh, hopefully in the next year or two. 

Alok Jha: So I suppose it's nothing on the geological timescale, is it? 

Dr Susannah Maidment: As I always say, they'll still be extinct tomorrow. Yeah, that's right. So, you know, what's the hurry? 

Alok Jha: To be honest with you, you couldn't come up with a better name than Cryolophosaurus.

So, I mean, that's quite good. I'm impressed if you can come up with a better one than that. 

Dr Susannah Maidment: Yeah, they bagged a good one, didn't they? There's also Antarctopelta, which has already been used as well, so.

Alok Jha: Also excellent. Why haven't we talked about that so far? Antarctopelta. Fantastic. 

So are there expeditions every year to Antarctica and the sort of associated islands to try and gather as much as possible whilst the conditions allow? Is there a sort of routine collection program going on? 

Dr Susannah Maidment: I'm not aware that anybody is going year in year out to Antarctica just specifically to look for dinosaurs. Obviously, you know, you need a lot of funding to do that sort of thing. It may be that the Argentinians go, there's a big group of dinosaur paleontologists in Argentina and they're very active in Antarctic research or have been historically.

I don't know whether they go every year, I doubt it, because putting on an expedition like that costs lots and lots of money and, you know, if you're going to study climate change or something like that, there's many sources of funding available to you to do that, but maybe a bit less so to look for dinosaurs.

 

Alok Jha: Let's make the case, because aren't there, some of the most important fossil sites on Earth occur sort of in the Antarctic and sub Antarctic ranges, Seymour Island, for example. There are really important places there for the history of geology, essentially, and then the kinds of animals that are living there.

Dr Susannah Maidment: There are, and pretty much everything that we're going to find there is going to be new because it's so undersampled relative to the rest of the world. And actually Gondwana or the Southern Continent, so Gondwana was a super continent that was made up of South America, Africa, Antarctica, India, and Australia.

Those continents are incredibly undersampled for vertebrate fossils relative to the Northern Hemisphere. in general. And then we've got Antarctica, which is even more undersampled because it's all covered in ice. Everything that we find is going to be something new and is going to inform us about past life and past climates and past environments.

Alok Jha: Why is Gondwana so undersampled? Is it just because there haven't been many expeditions or that universities and research expeditions tend to focus closer to home in the sort of North? 

Dr Susannah Maidment: Yeah, I mean, all of those things, I think it's, there's definitely a historical bias towards the Northern Hemisphere because palaeontologists have been working there the longest.

So North America and Europe is particularly well sampled. Asia is extremely well sampled as well. There's been a long history of paleontological research in China, for example. Parts of the Southern Hemisphere – there are active, large paleontological groups like Argentina and increasingly Brazil, for example.

Australia also – there are some paleontologists who focused on vertebrate paleontology and dinosaurs particularly. But across Africa, for example, it's much more poorly sampled. There's some paleontologists, vertebrate paleontologists in Southern Africa and South Africa, but it's much, much less well sampled just for historical reasons, really.

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You talked about Gondwana. Am I imagining correctly if I think of it as the sort of southern part of Pangea? Or is there a sort of difference in terms of when Gondwana came along and became significant? It is the southern portion of Pangaea, which was this supercontinent that stretched from pole to pole during the early part of the Mesozoic, and then rifting between the north and the South occurs, and we are left with these two continents of Gondwana and Laurasia 

So Laurasia is the northern hemisphere, which comprises today, north America, Asia, and then we get Gondwana, which is the southern continents from today. What we see as we go into the Mesozoic, after that rifting had occurred, we do see quite different faunas in Gondwana than we do in Laurasia, so all of our famous and favorite North American dinosaurs that we know from that period, like Triceratops and T Rex.

They're not present at all in Antarctica and we see different taxa and actually ecosystems dominated by different animals in the southern hemisphere. 

Alok Jha: What was it about the southern part of this supercontinent that made the dinosaurs the way they were compared to, as you said, the more famous T Rexes and the Stegosauruses and all of those?

Dr Susannah Maidment: That's a question that's really difficult to answer, given that the fossil record that we have is so, so poor, and we really don't have a good handle on the environmental conditions that these dinosaurs were living in because the Cretaceous dinosaurs, the late Cretaceous, are actually found in marine sediments.

Now they weren't living in the sea, um, they were just washed out to sea after they died. So we don't even know much about the rocks where they would have been living. So it's really hard for us to get a handle on that environment. But of course, one thing that we do know. is particularly by the time we get to the late Cretaceous, they would have been living in a place that was dark for a lot of the time, a lot of the year.

It's not clear whether these animals would have migrated in and out of Antarctica. During the late Cretaceous, there were still routes to Australia, although that was also close to the pole at the time. They must have been living in a place where it was dark a lot of the year, and that would have been quite challenging.

One of the things that people have done is to have a look at their growth rates and see whether they grew more slowly. At least for the herbivorous dinosaurs, whether they grew more slowly than their relatives from the northern continents at the same time. And actually they didn't. They seem to have maintained similar growth rates.

They weren't kind of slowing down their growth or anything as a response to living in this cold, dark place. Some climate modeling has suggested that although it would have been cool and the continental interior would have been cold, it would get nowhere near the freezing conditions of today and in fact the coast may never have dropped below freezing at all.

It wouldn't have been the inhospitable place that we know today. 

Alok Jha: You've got a job that probably many people are very envious of. If I can call you a dinosaur hunter, I think that's probably accurate, right? What does it involve when you're going on an expedition? What does the day to day look like for someone who hunts dinosaurs and fossils?

Dr Susannah Maidment: When we're planning the expedition, the most important thing that we're doing is working with local people in the area, where we go to work with local collaborators and to make sure that we understand all the sort of land laws and everything like that. And Antarctica is rather different from that point of view, isn't it?

Because I guess there aren't really any locals, so who are you working with there and whose land are you on? And that sort of thing is quite a different prospect. And of course, logistics of getting to where you're going are much more difficult if you're going to go to Antarctica than places where I do fieldwork, like the Western US and North Africa.

It's much easier, you know, I can just jump on a Ryanair plane to Morocco, I can't do that to Antarctica. So there's quite some challenges to being able to mount an expedition. And one of the big issues that we have is what happens to the specimens when they come back. So as I said, I work in Morocco. When we're working in a country like Morocco, the specimens will stay in that country.

Most countries have laws about where you can put the fossils once you collect them. I don't know the answer. I don't know what happens to fossils from Antarctica. I don't know what the agreements are, whether there are any agreements. I know that we have one here in the Natural History Museum that was collected in 1980s, late 1980s.

I know some Antarctic dinosaurs are in collections in Argentina. I know some are in the U. S. But I don't know who decides where those specimens go and who gets to own those fossils. It would be really interesting to address those challenges and kind of mount an expedition there.

Alok Jha: I guess people think about where to locate fossils more nowadays.

Because of ownership rights and, you know, not taking fossils from one country to another in the way that sort of colonialists might have done in the past. Talking of which, in Natural History Museum's collection, I do believe you have fossils from Antarctica collected by Robert Scott on his expeditions.

He must've been picking up quite a lot of things in the areas around Antarctica, there's some trees and other fossils there. Tell me about those. 

Dr Susannah Maidment: Yeah. So we actually have fossils that were found when they found the Scott expedition. On the sledge, they actually found a bunch of fossils that are actually just down the hall from where I'm sitting right now, stored in the paleobotany collection.

And they are of this tree glossopteris, which is well known from the Permian period. And we actually have fossils of this same tree from all around the southern continents. And this provided a key piece of evidence that the southern continents are once all united in a single landmass. 

Alok Jha: In terms of like how you use the fossils that you find then in that case, I just wonder, are there species that stand out for you in terms of the information they've given you or told you about some part of history that opened up your eyes to that ancient world? 

Dr Susannah Maidment: Well really every specimen that we find is a missing link to the past.

And every single new specimen adds more data to help us understand a picture of what life was like in the past and how environmental changes can affect species diversity. And fundamentally what we're trying to do is understand how biodiversity has changed through time. And that's our kind of central tenet of paleobiology.

So every single new specimen that we find adds a piece of data to that. One of the things that we can do with the Antarctic dinosaurs. And as I said, we have this one in the NHM that we are working on that I've been doing recently with it is looking at paleogeography. 

So we're looking at how animals evolved in terms of how they spread out across the globe and did that evolution occur because of vicariance? So because species ranges were split and species were isolated. Or did it occur through dispersal events from one continent to another, and then populations were isolated and evolution occurred there? Once we understand a bit about the family tree of these dinosaurs and the relationships between them, we can start to map those patterns of evolution and see how evolution actually occurred.

But we can also look at it the other way. If we have a good family tree of the dinosaurs, that can help inform us about how the tectonic plates broke up, because we can look at who's most closely related to whom and therefore who shares the most recent common ancestor. And so it can help us understand things like the breakup of Pangaea as well. So there's loads that we can do with every single new piece of data adds to this picture. 

Alok Jha: Do we know when Antarctica sort of moved to the position it's in now? And do we know, second to that. What were the animals living there at the time, if any?

Dr Susannah Maidment: I don't fully know the answer to that question. Antarctica was situated further north, not much, but somewhat further north, during the Jurassic period and it began to drift south with the rest of Gondwana during the Cretaceous period.

I don't know exactly when it got to its current location. It became glaciated about 30 million years ago in the Oligocene, and that was long after the dinosaurs were extinct. 

 

Alok Jha: So there weren't any dinosaurs trapped under the ice or anything like that, as far as you know. 

Dr Susannah Maidment: No, we won't find any dinosaurs, unfortunately, uh, preserved in any ice sheets if the ice completely melts.

Alok Jha: So it was a huge change to the creatures living there, and we don't know what was living there specifically, but so the species that you talk about, did they all just die off, or did they move north as the rest of the continents moved around? Do we know what happened to them?

Dr Susannah Maidment: No, we really don't. For the middle Jurassic ones, this Cryolophosaurus and Glacialosaurus, They would have been extinct, they were fossils by the time the Cretaceous ones lived. This is how long we're talking in terms of time. We don't know what caused them to go extinct.

We have just a couple of specimens, one or two specimens of each one. We just don't have that level of data. For the Cretaceous dinosaurs, they were actually living in the Maastrichtian, and that is the time period right before the dinosaurs went extinct, so it's right before the asteroid hit. So it is possible that those taxa were around and were actually wiped out by the end Cretaceous mass extinction.

Although again, we just don't have those rocks preserved to be able to give us that level of resolution. 

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Camilla Nichol: Hello, I'm Camilla Nichol, CEO of the UK Antarctic Heritage Trust. 

As a charity, we work to preserve and protect Antarctica's unique heritage, from the wreck of Shackleton’s Endurance and historic huts of early pioneers, to the amazing discoveries in climate science. Our mission is to inspire more people to discover, value and protect this precious wilderness.

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Thank you - enjoy the rest of the show.

 

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Alok Jha: Suzie, can you tell me how you got into this area of research? Paleobiology, what was your journey into it? 

Dr Susannah Maidment: This sounds like a story that's made up, but I promise it's not. When I was about seven, my grandpa, who is an electrical engineer, said to me, what are you going to be when you grow up? And I had given this some thought, age seven, and had decided that scientists look quite cool.

I think I had in my head somebody who wears white coats and pours different liquids into jars and they sort of explode and change color and stuff like that. And so I said, well, you know, I'm thinking about being a scientist, but I maybe like to be a princess as well. And he was quite clear that I should definitely go down the scientist route rather than the princess route, which seemed reasonable to me.

 

And then he said, well, what sort of scientist would you like to be? It hadn't even occurred to me that there were different sorts of scientists. So I said, I don't know. And he said, well, why don't you be a dinosaur scientist? I, you know, seven, like dinosaurs, had a stegosaurus money box and a blow up stegosaurus and stuff like that.

So I said, okay, then that sounds good. I'll do that. So I did. 

Alok Jha I mean, as simple as that is it. I love the fact you had a blow up stegosaurus and now you're an expert in stegosaurus dinosaurs. 

Dr Susannah Maidmenet: Well, actually, when I, um, I applied for a PhD to work on a whole group of dinosaurs.

Um, a really interesting PhD. And when I got to the interview, the supervisor who had advertised this position said, Oh, uh, there's been a thing, basically you can't do that PhD anymore. Um, I've had to give it to somebody in the year above you because his PhD went wrong, so it's not available anymore. And I thought, cool, well, why am I here?

Like what, what am I interviewing for? Anyway, I, he said, well, let's interview you anyway. And we did the interview and then he phoned me up a week or two later and said, I'd really like you to come and work with me and I've got an idea for another PhD. And it would be on stegosaurs. Would you like to do it?

And I thought, yeah, I had this blow up stegosaurus and stegosaurus money box. So it seems appropriate. So yeah, sure. Why not? 

Alok Jha: Is climate change having an effect on the kinds of fossils that you can now find? I'm just thinking from a layman's point of view, if ice sheets are retreating generally around the world, and especially in places like Antarctica and the Arctic actually, are you finding new things as a result? And it's kind of the bittersweet lining to a terrible thing.

Dr Susannah Maidment: I think that inevitably there will be, as more land is exposed, more things will be found. And I don't know whether anything has been found in a place where 30 or 40 years ago there was permanent ice sheet and now that ice sheet's retreated and we're finding things. I think it's inevitable that these sorts of things. Will start to give up their secrets. Antarctica will start to release its secrets as the ice melts. 

On the other side of the coin, one of the things we're seeing in places where I work, like Morocco, we're seeing increased interest in the fossil trade from people like subsistence farmers, because they're unable to grow crops because of climate change, there's not enough water.

Desert is encroaching on their livelihoods. And so they're turning to the commercial fossil trade to actually survive. So climate change is having an impact on how we find dinosaurs, whether it's revealing new land in Antarctica or causing people to turn to selling fossils in Morocco. 

Alok Jha: You've had, and you still have, a very distinguished career searching for dinosaurs. And I just wonder, in that time, is there a favourite, is there a dinosaur that you particularly like? I know it's a difficult question for someone who makes a living, you know, looking for all different types and putting them into the big puzzle piece, but is there one you love the most? 

Dr Susannah Maidment: That's a really, really hard question because I love different ones for different reasons.

Yeah, probably my favorite dinosaur here at the Natural History Museum is kind of insignificant to the public, at least specimen called Dasentaurus, which was the first stegosaur ever found. And it was found in 1875 in a brick pit in Swindon, and it is actually on display. 

 

Alok Jha: That's quite far from Antarctica, isn't it?

Dr Susannah Maidmenet; That is relatively far from Antarctica, yeah, Swindon. I didn't find it, but I have studied it a lot. So that kind of has a special place in my heart, as one I spent a lot of time working on during my PhD. 

Alok Jha: And what does it look like, that one? Is it a terrifying dinosaur? 

Dr Susannah Maidment: It's a stegosaur, so it's closely related to Stegosaurus with the plates on its back.

Except we don't actually have any plates preserved for this particular one. We do have some tail spikes preserved for it. We've just got the back half of the animal, so we don't have that much of it. We don't have any heads or anything, so it's not very well known. 

My most exciting find was when I was involved in a dig where we excavated the neck and skull of a Camarasaurus.It's a long neck, long tail dinosaur. So it's got very long neck, very long tail. It's got big forelimbs that are slightly taller than its hind limbs. And quite small heads and spatulate teeth. So teeth that were a bit like a spoon, really. 

Alok Jha: How big would it have been, roughly?

Dr Susannah Maidment: Oh, 30 tons, maybe. Pretty tall, probably two and a half, three meters at the shoulder, something like that. Okay. Yeah. So pretty big animals from the upper Jurassic of the Western US. 

Alok Jha: Okay. So sort of small bus sized. 

Dr Susannah Maidment: Yeah. Bigger, bigger, longer than a bus, but a bit lower probably than a double decker bus. Yeah.

Alok Jha: And this is a difficult question to answer, but I'm just curious, where next are you going to be looking in terms of like these prehistoric environments you've described? You can only piece them together with a patchwork of fossils that are all incomplete from different parts of the world and hard to get, and there's so much we don't know because every fossil you find that probably just raises more questions, but are there specific parts of the fossil record or prehistory that you're particularly interested in just finding out more about? What are the biggest questions for you are? 

Dr Susannah Maidment:The time that I'm focusing right now is the middle Jurassic, and this is a time period of around about 168 to 165 million years ago. For me, it's really interesting because. It's where we have the radiation of all of the major groups of dinosaurs. So prior to this time, we've mainly just got two legged meat eating dinosaurs, the theropods and prosauropods, which are early representatives of the long necked, long tailed dinosaurs, and a few herbivores that are kind of boring and two legged and quite small and aren't doing very many interesting things.

Alok Jha: Oh, well, you, you think they're not doing interesting things. Who knows what they were doing? 

Dr Susannah Maidment: That's true, but they're not very morphologically diverse. They're all quite similar. 

Alok Jha: Fair enough. 

Dr Susannah Maidment: And then after this time, we get in the upper Jurassic, we have this huge diversity of dinosaurs. All the ones that you could name when you were seven, you know, Stegosaurus and Diplodocus and Apatosaurus and Allosaurus and all these huge herbivores and these huge meat eating dinosaurs.

But we don't know what happened in the middle there. We don't know how we got from these relatively uninteresting ecosystems of the early Jurassic to these upper Jurassic, these incredibly diverse ecosystems of the upper Jurassic. So the middle Jurassic is a time period I'm really interested in, and it's very, very poorly sampled globally.

Sea levels were quite high at the time, and that means that we don't have lots of land deposited rock worldwide. So I said a few times already that I've been working in Morocco, that's on a middle Jurassic site. 

We've also got quite a bit of middle Jurassic in the UK, which is somewhat underexplored. Around Oxfordshire and Gloucestershire, we have quite a lot of exposures of shallow marine rather than terrestrial, but very, very shallow. There are some dinosaur fossils from there, they've not really been well characterised.

There's an interesting opportunity to go back and revisit what we think we know and that's a lot of what we do really. We don't just go out and dig up new stuff. We spend a lot of time going back through our collections and looking at what is already in the museum collections and every new dinosaur that's found adds information to what we've already found, of course. So we can go back and reappraise what we've got in the light of new data.

Alok Jha: I wonder about that because as you say the fossil record is patchy but there's huge amounts of time that you're sort of trying to cover with little bits of bone and other morphological things that you find here and there. How does a fact become certain about a particular part of history?

How much information do you need? How many fossils do you need to know that that is the period when X happened or Y happened? Or will there always be a massive amount of uncertainty, lots of arguments and things? I'm just curious how argumentative your field is. 

Dr Susannah Maidment: I think there are some things, there's no facts in science, are there really?

At least not outside of physics and maths. There's only hypotheses that we can test beyond all reasonable doubt. And I think that things like the end Cretaceous mass extinction being caused by a meteorite hitting the earth is now accepted as as close to fact as we're ever going to get. There's so much evidence for that. We're all really, really happy that that's what happened, that that is what caused the mass extinction at the end of the Cretaceous. And there's very few voices that disagree with that in the community. 

Another example would be that birds evolved from dinosaurs. Maybe 40 years ago, it wasn't widely accepted. It was a debate, but now we've found so many new fossils of birdlike dinosaurs, feathered dinosaurs, huge number from China have come to light, which make it beyond all reasonable doubt that that is the case, that birds are dinosaurs and that they evolved directly from dinosaurian ancestors.

So those sorts of things, I think we're really, really happy about. Of course, as we go further back in time, the fossils get rarer and rarer and less well preserved, and there's still really big questions. Even really fundamental questions about which major group of dinosaur are most closely related to each other is still the matter of some debate.

So there's a lot that we still have to find out, but we can resolve debates if we have enough data. 

Alok Jha: And enough fossils, I guess. Which leads me back to Antarctica. We talked earlier about difficulty of finding fossils in that part of the world and the fact that perhaps there are not necessarily lots of expeditions going on down there.

As somebody who researches this stuff, I just wonder how important is it that we do try and fill in the fossil record from places like that? What are the questions you can answer if you were sort of collecting more often from down there? 

Dr Susannah Maidment: Fundamentally, as I said earlier, our aim as paleobiologists is to document how life has changed, how biodiversity has changed on earth in response to changing environmental conditions and changing evolutionary conditions.

We're missing a big part of the jigsaw. We're missing virtually the whole fossil record of an entire continent. There's an enormous amount that we could be learning if we were launching regular expeditions down there. If we had the funding to go down to Antarctica every year and collect, who knows what we could find.

We will be shedding an enormous amount of light on past biodiversity, past climates, past environments, and how climate change has influenced how diversity has changed in the past, which of course informs our knowledge of the future on a warming earth. 

Alok Jha: If you were offered a trip to Antarctica to go and hunt for some fossils. How would you, uh, respond?

Dr Susannah Maidment: Well, I'm quite a cold person, so as long as they could promise me a great deal of warm clothing, then I would absolutely, I'd be delighted to go. 

Alok Jha: I think it comes with the territory, .

Dr Susannah Maidment: Okay, that's fine. Then

Alok Jha:  you get all the warm clothing in the world. 

Dr Susannah Maidmenet: Yeah, that's perfect. 

Alok Jha: Alright, well just for finally, before you go, let me ask you, why does Antarctica matter to you?

Dr Susannah Maidment: I think it's the last wilderness really on earth, isn't it? It's the last unexplored place and it's just tantalising for what we could find there. what we could find about the earth, about the earth's past and about life on earth. There's nowhere else on earth where the potential to find something so radically different and completely change our understanding exists really.

Susie, thank you very much for your time. Thank you.

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Thank you for listening. A Voyage to Antarctica is brought to you by the UK Antarctic Heritage Trust, and made possible by support from Hurtigruten Expeditions. 

To find out more about our guests and how you can support the Trust, please head to our website at www.ukaht.org, or find us on social media. If you enjoyed this episode, please don’t forget to follow and rate us, wherever you get your podcasts. It makes a huge difference to us.

Please join us next time, when I’ll be talking to journalist and author Julian Sanction about the harrowing and epic survival story of the Belgica; an early polar expedition gone terribly wrong.

A Voyage to Antarctica was presented by me, Alok Jha. Theme music is by Alec Hewes, and Editing and Additional Music is by James Stickland. The show is Produced by Jessica Norman. 

See you next time.