Heritage & Culture

T. Rex: The Killer Question

T.rex The Killer Question at Peterborough Cathedral

This summer, the Natural History Museum’s spectacular touring exhibition of animatronic dinosaurs comes roaring into Peterborough Cathedral... The exhibition – focused on the undoubted superstar of the dinosaur world, T. rex – includes moving dinosaurs, dinosaur scenes and a life-size T. rex skeleton. It also poses the killer question: ‘Was T. rex a ferocious hunter or a mere scavenger?’ The Moment talked to Principal Researcher at NHM, palaeontologist Dr Susannah Maidment, to pose this and other burning questions... What can we learn from dinosaurs? Could T. rex outrun a Jeep? And why the ludicrously tiny arms..?

 Susannah MaidmentEveryone has a bit of a fascination  for dinosaurs, but what is it about T. rex in particular that people love so much?
I think that it’s to do with this vision of the ultimate predator. What particularly captures children’s imagination, but actually many adults as well, is the idea of this huge animal – far bigger than anything that we have alive today – that would be genuinely terrifying to us, with this head that is effectively a killing machine. We haven’t measured the bite force of absolutely every animal, but as far as we know T. rex has the strongest bite force of any animal that’s ever lived. It could chomp us in half with no problem! It’s part of our nightmares, really, and I think that’s probably what captures people’s interest. Also, T. rex hasn’t actually been dead that long, in geological terms. It died out 66 million years ago. Compare that to, say, Stegosaurus, which died 150 million years ago, and think about all the erosion and tectonic forces that could have acted on it in that time… Because of this we have hardly any Stegosaurus fossils, but we have lots of T. rex fossils, which means it has the
benefit of being known from a number of rather complete specimens. It was one of those early dinosaurs that we knew a lot about from those skeletons, as opposed to some of those we only knew from fragments of teeth and little bits of bones. Early palaeontologists recognised these belonged to giant reptiles, but what they looked like beyond that was hard to work out. They were making their best guesses from analogies with other, living animals, but it wasn’t like you could mount those skeletons and show them to the public, as you could with the more complete T. rex. So, partly it’s because it’s so well-known from fossils and has been mounted so many times, but also it’s this idea of the ultimate super predator.

T. rex existed at the very end of the dinosaur period, in the Late Cretaceous, so does that mean they would have witnessed the catastrophic end of the dinosaurs’ reign?
Yes! It appears they lived between 68 and 66 million years ago, in what is now western USA, so at least some T. rexes somewhere would have been witness to the asteroid when it hit.

T-Rex skeleton head black background © The Natural History Museum London

T-Rex skeleton © The Natural History Museum London

How do you classify dinosaurs? Is it difficult sorting out what’s what and putting them into neat categories?
It’s not a straightforward process! What we all learned in biology at school was that what defines a species is two living things that can breed to produce viable offspring. Actually, it turns out that’s not a very good definition of species, because if you bring a polar bear and a brown bear together, or a wolf and a dog, they’ll breed to produce viable offspring, but we recognize them genetically as different species. With the dinosaurs, we don’t know who could breed with whom. We don’t have any DNA, so we can’t look at their genomes to say how different they are from each other. And of course, all things evolved from each other, very, very slowly, over time. So what we do as humans is put envelopes around things and say that this thing is one species, and this is another species. And the way that palaeontologists do that for extinct animals is by looking at the shapes of the bones, and differences in the shapes of the bones. We’re trying to identify features on the bones that are entirely unique to that animal.

That sounds simple, but it’s really not, and if you ask five different palaeontologists to look at five different skeletons of closely related animals and say: ‘Where do you draw the boundaries between these?’, they will probably come up with five different answers. One may look at the shape of a bone and say: ‘This is an entirely unique feature…’ while another might conclude that it’s just due to the bone being squashed in the ground for over 60 million years and not a feature at all. So, it’s difficult! We can use additional information, such as whether animals were living in the same place at the same time, or were separated by millions of years. We know, for example, that we share a common ancestor with orangutans, about 12 million years ago. So, if we have animals that are separated by 15 million years, we can say they’re probably not the same species, because we think evolution happens faster than that. But even so, it isn’t straightforward – and this has been exemplified for T. rex by a paper that came out just a few weeks ago, which actually split T. rex into three different species: Tyrannosaurus imperator, Tyrannosaurus regina and Tyrannosaurus rex. T. rex enthusiasts across the world have been appalled by this! But our need to be able to talk in a common language requires us to call these things something. We could just refer to them by the nicknames they’ve been given by palaeontologists – like Stan and Sue – but in terms of understanding evolution, and how evolution proceeds, that’s not very useful. Ultimately, some of these are questions that are not answerable.

Static T-Rex model head © The Natural History Museum London

T-Rex head © The Natural History Museum London

Because T. rex has been known about for a long time it’s also appeared in films going right back to the 1920s. But how has our understanding of T. rex changed in that time?
Well, as I said earlier, in terms of what it actually looks like – the shape and the way it stood, and things like that – it’s one of the few dinosaurs that hasn’t had a major makeover. There have been some changes. We now think that these dinosaurs didn’t drag their tails on the ground, as early depictions show. We now see them with a much stiffer spine, with a tail counterbalancing the front of the body. The thing that’s really changed is our appreciation of the biology of dinosaurs in general. When they were first discovered, everybody thought they were very lizard-like, very reptilian. It was with the understanding that birds evolved from dinosaurs that we came to realise that dinosaurs probably had a much faster, more efficient metabolism and perhaps were much more bird-like. We know that some meat-eating dinosaurs cared for their young, and we have fossils of meat-eating dinosaurs sitting on nests.

The other thing that’s interesting about tyrannosaurids as a group is that some early members of the lineage, leading to T. rex, were feathered, and one of the features that you sometimes see in popular literature is T. rex displayed with some sort of integumentary covering. Now, we don’t have any fossils of T. rex feathers and, actually, the evidence points more towards it having scaly skin. But the rocks it’s found in don’t really lend themselves to the preservation of those sorts of features. So, it’s tricky – but I think it’s certainly possible that juvenile T. rexes had fluff that helped keep them warm which they then lost as they got big enough not to need it, and might even have had some sort of fluffy mane.

We know the connection to birds features in Jurassic Park (1993), but when was that connection first understood?
It was first proposed by Thomas Henry Huxley, who was a big Darwin fan and proponent of evolution by natural selection in the latter part of the 19th century – but it was basically ignored. It wasn’t really suggested again until the 1970s when there were some proponents, but the thing that really brought it to full attention was the discovery in the early ‘90s of some amazing deposits in China. These are lake deposits interbedded with volcanic ash, and within them there are preserved dinosaurs with soft tissues – and there have now been hundreds of examples found of dinosaurs with feathers. And when people saw the feathers and saw that these were exactly the same features that you see on birds, then the other aspects of dinosaur anatomy really fell into place. So, for example, meat-eating dinosaurs have a wishbone – a furcula – which, of course, birds do today. When you look at Archaeopteryx, which is said to be the first bird, we can see it looks like a dinosaur. It’s got a toothed beak, it’s got a long bony tail – but it also has feathers and a reversed claw on its toes for perching, like a bird. So it has these features that are transitional between birds and dinosaurs.

Hadrosaur mother with hatchlings © The Natural History Museum London

Hadrosaur mother with hatchlings © The Natural History Museum London

Why did they develop feathers?
Our best guess right now is that feathers probably evolved for thermal regulation – so, they probably evolved like mammal fur, to keep the animal warm. So, these are animals that are evolving a warm-blooded metabolism. Dinosaurs share a common ancestor with crocodiles
and birds, but crocodiles are cold-blooded and birds are warm-blooded, so somewhere along the lineage warm- bloodedness is evolving. That must have happened in the dinosaurs somewhere – possibly even before, but probably not. So, we’ve probably got small, meat-eating dinosaurs that have elevated metabolic rates evolving warm- bloodedness and needing to keep warm. And so they develop a covering that’s a little bit like mammal hair.

Going back to T. rex, there’s one thing that I’m sure everyone must have wondered at some point… Why the tiny arms?
We don’t know! There have been various, slightly strange speculations about what they might have been used for. They do have muscle attachments and they were still able to do something with them. All dinosaurs started off using their forelimbs for grasping and probably pulling food to their mouths, but when you’ve got a head the size of T. rex, you probably don’t really need to do that – you literally just chomp! Effectively, I think their arms are replaced by their head, so they probably are a vestigial structure.

The exhibition asks visitors to consider whether T. rex is a predator or scavenger. Can we ever have a definitive answer to that?
No, I don’t think we can unless somebody invents time travel! We can look at evidence in the fossil record of bones that have been chewed and digested, and we can look at scavengers today and see what damage they do to bones. But I don’t think it necessarily has to be one or the other – it could well be that these animals were doing both. I mean, if you’re a T. rex, and you’re hunting a nice, fresh piece of meat, but you happen across a recently dead Triceratops that’s tripped up and broken its leg, I doubt you’re going to pass up that opportunity for a quick bite. So I suspect that they may well have been doing both. We do see predators in the modern day who will engage in scavenging behaviour if they need to – and if an important part of your diet is, say, being able to extract bone marrow or chomping and digesting bone that others can’t, then you are going to need a bite force that will allow you to do that.

This exhibition involves animatronics, which means building life-size models of dinosaurs that move… Do palaeontologists themselves learn from that process?
As scientists we don’t make physical models of our dinosaurs anymore; these days, we would make a digital model. But digital models are fundamental for our understanding of behaviour. So that’s how we’ve calculated the bite force of T. rex – through a digital model of the skull, manipulating that skull using engineering techniques which allow us to see how it deforms under stress. I work on locomotion, working with biomechanicists who look at living animals, and we make digital models of dinosaur legs, plot all the muscles, and we can then see what the ranges of motion are. When you get really advanced down this route you can even calculate running speeds, seeing how much stress the bones could withstand. This has been done for T. rex by my colleagues at the Universities of Manchester and Liverpool. They built this 3D model which they
put through an evolutionary learning algorithm and gave it all sorts of rules to obey, like gravity, and used engineering methods to tell the model how much stress the bones could withstand, based on information from living animals. Basically, if a bone exceeds a certain level of stress during locomotion, it’s going to break. What they found was that T. rex actually couldn’t run. It couldn’t perform a running gait, which is when both feet are off the ground at the same time; if it had done that, its bones physically would have broken. But what they found was it could walk at about 12 miles an hour, so it could still walk faster than most humans can run – but it couldn’t chase down the Jeep as it did in the original Jurassic Park.

Ankylosaurus © The Natural History Museum London

Ankylosaurus © The Natural History Museum London

Jurassic Park obviously got a lot of people excited about dinosaurs – but what made you want to become a palaeontologist?
Okay, true story – although it doesn’t sound like it… When I was seven, my grandpa – who was a very inspirational person to me – said ‘What are you going to be when you grow up?’ At the time I was sort of wavering between scientist and actor. My grandpa was very keen to make me go down the scientist route, so he asked ‘What sort of scientist?’ I didn’t really know there were different kinds; to me scientists were people who wore white lab coats and mixed coloured liquids and made things explode. But I really liked dinosaurs, so he said ‘Well, why don’t you become a dinosaur scientist?’ So I said ‘All right!’ And that was that! It made all my careers interviews at school really easy – and then I went on to do geology at university. When I was a kid we used to have lots of family holidays down on the Dorset coast – Charmouth and Lyme Regis – and finding ammonites was always part of my psyche. I loved collecting fossils and shells and stones and things like that.

Although all younger kids seem to love dinosaurs, it’s quite unusual for a girl to pursue that…
As a teenage girl it was sort of a secret hobby, a secret interest, which I couldn’t really say out loud. It just wasn’t very cool to say you were into dinosaurs when you were a 14-year-old girl! But then Jurassic Park came out when I was around 13 and it brought dinosaurs to the public eye again. It made it more socially acceptable. I think Jurassic Park did a huge service to really bring dinosaurs to the forefront of people’s minds and attention – and for me, personally, probably helped me not look like a total weirdo!

I think that in order to make it more socially acceptable for girls in general, or to try and encourage girls to do it, science has to be seen as a discipline that not just boys do. And I do think we have to change perceptions of palaeontologists. And it’s not easy because, honestly, I am one of just a handful of women worldwide who study dinosaurs. There are lots of female palaeontologists in other disciplines, and there are PhD students and postdocs and things like that, but I’m one of probably three or four women worldwide who studies dinosaurs as their permanent job.

Deinonychus close up of head © The Natural History Museum London

Deinonychus © The Natural History Museum London

The study of dinosaurs is necessarily a study of a mass extinction. What can we learn from that?
Looking at extinction in the fossil record is really important. Actually, the largest mass extinction was 250 million years ago, at the end of the Permian, when virtually everything alive went extinct – up to 95% of life on Earth. At the end of the Cretaceous, when the dinosaurs died out, it was more like 65%. But because the dinosaur extinction didn’t happen that long ago in geological time, it’s the one we know the most about. There’s very little debate these days about what caused it; we have the crater, we have the impact layer, we have a good idea of what effect that would have caused. But there have been five major mass extinctions, and many other smaller mass extinctions through time. And what we can do is look at those and find out how quickly things went extinct, look at patterns of biodiversity and how they changed as a consequence of that extinction, and understand how long it took for ecosystems to recover. We can use the past to help us predict what might be happening in our future; so if we want to predict how the ranges of certain animals might change, we can go back and look where extinction has occurred and how the ranges changed. At the end of the Permian it took tens of millions of years for ecosystems to recover. That mass extinction was probably caused by the largest volcanic eruptions ever to have happened on Earth, which pumped huge amounts of carbon dioxide into the atmosphere, and so, in some ways, is a better analogue to what’s happening today than the Cretaceous mass extinction. That was a geologically instantaneous event that occurred because of an extraterrestrial impact, so the causative mechanisms are slightly different. But nonetheless, we can still maybe compare how the fauna recovered after the K-Pg (Cretaceous-Paleogene extinction event) versus the Permian – how we see very rapid recovery after the Cretaceous mass extinction versus very elongated recovery due to massive climatic perturbation that occurred in the Permian. So, I actually think that palaeontology has never been more important to study than today, because we can’t predict the future from looking at today. We have to go back in time to discover what happened, how things changed and how they recovered. That’s a huge multidisciplinary effort.

Could such an effort actually provide a solution to climate change?
I think what’s really devastating is the amount of funding that is put into things like space travel, and the development of space flights; if that money had been used to fund 30 climate scientists for three years, we would have solved climate change. The perfect example of that is COVID vaccines. People have been working on mRNA vaccines for years, but the leap forward happened because suddenly everyone committed the money to solving the problem. So, it’s not that there isn’t the technology. It’s not like there aren’t the brains. What there isn’t, is the money and the will. This is why raising awareness of extinctions on our planet is so vitally important.

From the Dean

Dean of Peterborough, the Very Revd Chris Dalliston, on what it means to have dinosaurs in the Cathedral…

In the past, science and the Church have sometimes been at odds, not least on the topic of evolution. Does hosting dinosaurs in a cathedral show just how far we have ‘evolved’ with regard to this – and how important is it that Church and science are not seen as being in opposition?
It is certainly true that there has been this perception of a fundamental divide between faith and science, although of course many of the early scientific discoveries were made by clergy scholars and researchers! In fact, these are really two different ways of understanding our place within the universe and the created order. Science tells us how things happened, faith is more about the why! We believe that God has a destiny for human beings and for the created order, and a purpose, but that does not mean that scientific truth is any less valid. In fact, it is really important for us to listen carefully to what science has to tell us about the way the world works.

It seems that EVERYONE, young and old, loves dinosaurs! How important is that for the Cathedral and its hosting of this exhibition?
We believe that the Cathedral belongs to everyone. It is a big, gracious, generous space in which people of all backgrounds are welcome to explore, discover and, in fact, have fun! Hosting an exhibition like this offers a real opportunity for people to discover not only more about the dinosaurs but about the Cathedral and the faith for which it stands.

One thing everyone knows about dinosaurs is that they died out. Does that have something to teach us?
Christianity believes that the world is a gift of a loving Creator God, but it is both fragile as well as resilient. The extinction of the dinosaurs reminds us that we need to take huge care with our environment and with the way we exploit the natural world. It would be foolish and arrogant for humanity not to recognise that other species have been and gone in the past, and we should not assume that we are any different.

T. rex: The Killer Question

Monday 18 July until Saturday 3 September 2022
Peterborough Cathedral
Various times

See the Natural History Museum’s touring exhibition of moving and roaring animatronic dinosaurs inside 900-year-old Peterborough Cathedral. The exhibition asks the killer question: ‘Was T. rex a ferocious hunter or a mere scavenger?’ Come along and decide what you think!

  • Tickets: £6 per child (aged 3-16 years), £8 per adult and £25 per family ticket (2 adults and up to 3 children aged 3-16 years, or 1 adult and up to 4 children aged 3-16 years). A booking fee applies.
  • BOOK NOW: www.peterborough-cathedral.org.uk/t.rex or call Ticket Source on 0333 666 3366 during office hours (additional £1.80 fee applies to phone bookings).
Leave a Reply

Comments are closed.

Register an Account