Interview with a dino expert

Palaeontologist Mike Benton on dinosaurs’ true colours, mass-extinction events and life working in the field

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Mike Benton

Mike Benton is Professor of Vertebrate Palaeontology at the University of Bristol and is a world-renowned dinosaur specialist. His areas of interest include the diversification of life throughout time, the origin of dinosaurs and the end-Permian mass-extinction event, the latter seeing him work in the field frequently both in Russia and China.

How It Works: What is your special area of expertise?

Mike Benton: I am a professor of vertebrate palaeontology at the University of Bristol and my job here is teaching students at undergraduate and postgraduate level as well as doing research. I am greatly interested in a variety of ancient life, particularly dinosaurs, and a couple of areas I am currently working in is the origin of dinosaurs and reconstructing colour in their and ancient birds’ feathers.

HIW: Could you go into more detail on your colour-reconstruction work?

MB: Yes, the colour reconstruction is particularly interesting. This work was first published in 2010, which was the first-ever announcement of objective evidence of coloured feathers in dinosaurs and that was quite a claim. I think it was a topic people thought that we would never know the answers to. However, we were able to rely on a fair number of fossil feathers that were exceptionally well preserved and deep within their internal structure you can see colour-bearing organelles. By comparison with modern feathers where we can link different pigments within organelles within the feathers giving a range of colours like black, white, grey, brown and ginger, we find the self-same organelles in fossil feathers that are over 100 million years old. So we are able to pinpoint some of the colours – not all of the colours – to a great degree of accuracy.

HIW: Why is determining the colour of dinosaur and ancient bird feathers important?

MB: I suppose initially it was very much the Sherlock Holmes aspect of everyone saying it couldn’t be done. So by using some smart observations and techniques we proved it to be possible and solved the mystery. Then, having done the trick of course you could say well that’s it, it’s done and that is that. But we would argue there is a broader significance, because terrestrial vertebrates today, including birds and mammals, are highly visual creatures, and a great deal of evolutionary success depends on signalling, and that in turn depends on colour and patterns and vision. So to be able to extend this big area of animal behaviour and sexual selection with which research started with Charles Darwin among others, back in time to an iconic group such as dinosaurs we feel is very interesting. It tells us something about behaviour, it tells us something about vision capability in extinct organisms and, importantly, I think it tells us something about the origins of biodiversity. That is because vision and sexual selection and behaviour are key elements of birds and mammals today, so to be able to track that back is quite helpful in determining how those groups got established and how they got to be so successful.

HIW: Could you give an example of the type of work you are currently undertaking?

MB: Well, as you are currently aware, the nature of university research is that nobody works alone and so I probably work with 50-60 other people at any one time, many of whom are my own students and other researchers at other institutions. So yes, we have funded research going on at the moment taking that colour concept in ancient bird and dinosaur feathers forward, but we have also just submitted a paper before Christmas on another area.

I have recently been working with some Chinese colleagues in Yunnan, looking at Triassic age rocks to try to understand the nature of the recovery of life from the devastating end-Permian mass extinction, which happened 252 million years ago. And the rock successions in south China have rapidly become a honeypot for researchers who are interested in this critical time in the history of the Earth and life as they are rich in fossils and cover a vast area where there is room for everyone. The paper we just wrote was looking at unusual tracks we have found in a flat surface covered in strange markings. This flat surface is an ancient seabed and scattered over this are all kinds of shells and fossilised fish and all the sorts of things you would expect. However, what was also imprinted into the soft mud are some beautifully preserved strange markings in double sets, about half a metre to a metre wide – so they were made by quite a large animal – and they seem to be punt marks, as if the animal that made them punted along the bottom of the seabed. These punt marks meander across this flat surface and loop over tens of metres, so we mapped them out and measured them up and compared them with various possible makers, and it seems almost certain now that they were made by a marine reptile from the Nothosaur group.

Nothosaurs had a set of four paddles and nobody had detected their prints on the seafloor before. They were thought to be free-water swimmers and top predators and they were very new at that time in history. They were a newly-evolved group, part of this explosive recovery of life, and what we believe this proves is that these animals were punting along the seabed, which was not their usual form of locomotion (they typically swam like seals or dolphins), and they were doing this to disturb organisms off the seafloor such as lobsters and other shellfish. So they were probably ploughing through the seabed mud, trying to disturb the creates within, flushing out prey so to speak.

HIW: What is life like working in the field?

MB: Palaeontologists have always done field work and it is commonly the case that they do so for two reasons. For many palaeontologists today the main drive is to find new species of dinosaurs or anything else, so every year huge expeditions are mounted in the American Midwest, Mongolia, Argentina, China, Australia and many other parts of the world, where a few established academics will go with a team of five or six students and other enthusiasts looking for fossils. Now, if they are lucky they find complete skeletons, wonderful new fossils and they get to write papers about a new dinosaur.

The other reason palaeontologists go into the field is to find evidence of evolution. I have given one example of where we weren’t finding a new species or a new skeleton fossil, but instead we were finding evidence of ancient behaviour. So certain kinds of excavation and study in the field can be for palaeoecology, trying to reconstruct food webs and modes of locomotion, or they can be about looking at patterns through time, going up metre by metre in rock formations and analysing fossil groups and seeing how they change.

HIW: Does more weight fall now on that evolutionary research than simply finding more fossils?

MB: I think that the norm these days, as it has to be in all branches of science, has to be some of what we do is what we refer to as a ‘fishing trip’, which is where we go out looking for something but you don’t know what that is going to be. Of course, that is not necessarily the most efficient way to go about things because you can go ‘fishing’ for a long time and find very little. In contrast, what I prefer – and I think the majority of palaeontologists prefer – is to go into the field with an objective. So you go to a particular part of the world, and at the moment lots of people are going to south China, as there is access to a certain quality of data, meaning it is possible to make a bid for funding and make a case for finding the answers to a particular unanswered question. So questions such as how and how fast did life recover from near annihilation after the end-Permian extinction event. You set up the parameters of the research and decide where to go and get the necessary funding and select which techniques and processes you are going to use to ensure data is gathered in advance – that is not a fishing a trip, as you have an objective and questions to answer.

HIW: Could you talk about the end-Permian mass extinction?

MB: It is a very interesting part of the history of life that there have been mass extinctions. This is something that Darwin and the other Victorian scientists knew nothing about. It is one of the biggest discoveries of the last century. The most famous mass-extinction event is the K-T event, which is famous for two reasons; first, it it is the most recent, occurring 66 million years ago, and second, it is the one that wiped out the dinosaurs. It wasn’t the only mass-extinction event and it certainly wasn’t the biggest. Within the last 500 million years most people agree there were at least five mass extinctions, four of which being the same size as the K-T event. The remaining one, however, was on a different order of magnitude and that was the end-Permian. It was the biggest of all. That claim is based upon all different kinds of estimates on the amounts of species lost. Only 10 per cent survived. In ecological terms that was huge. If you knock a couple of species out of a food web it will survive, with new species emerging over time and plugging the gaps, but if you knock 90 per cent out them out, then it is very likely that the entire ecosystem will collapse and disappear. It is then that life really needs to restart from a different level.

My final point, I think, would be that the evidence is that after the K-T mass extinction the dinosaurs had gone but nothing major or structural had really changed, after the end-Permian forests disappeared on land and in the sea reefs disappeared. That kind of level of fundamental loss is unique to that event, which is why people are honing in on the Triassic, which is the period that directly follows the end-Permian event, trying to see piece-by-piece how life came back from such a devastating collapse.

HIW: Is that study of the end-Permian event and Triassic recovery a hot research area right now?

MB: I think it is, because the K-T event was a really hot area in the Eighties and Nineties following the famous impact hypothesis paper, but they were not looking at the end-Permian as the dating was difficult and most of the good sections for study were in difficult-to-reach areas of the Earth. It was very hard to get to certain places and, to a degree, still is. However, with places like China now being very accessible that has changed.

HIW: Why is China so hot right now for palaeontologists?

MB: It is partly an accident of history, the fact that there is an area of geology as large and varied as the whole of Europe which hadn’t been explored until the Eighties and Nineties. All the work that has been done elsewhere in the world from 1800 up to the present day is now happening in China at a super-fast rate. I don’t think China is over-stocked with spectacular fossils, it’s just that we are now making up for 200 years of missed work, if you like. And it is all coming incredibly thick and fast!

HIW: Is it true that you have a dinosaur named after you?

MB: Well, yes, it’s true, but it technically isn’t a dinosaur but a species of rhynchosaur called Bentonyx. It was named by some of my students about four years ago and it was very nice and I didn’t expect it. The reason is that I had worked on these strange creatures called rhynchosaurs in my PhD and they thought they would name one after me. It really was very nice.

So rhynchosaurs were from the Triassic and they lived side-by-side with the very first dinosaurs – they have no living relatives today. They were an important group of plant-eating reptiles before the dinosaurs got established and died out about 225 million years ago, shortly after the dinosaurs exploded and became very dominant. Rhynchosaurs were about two metres (6.6 feet) long, had a very broad skull and a remarkable system of jaws and teeth that appear to have been designed to deal with incredibly tough vegetation. It seems that just about the time they became extinct the world’s climate got hotter and dryer and the nature of vegetation changed, leading to the plant-loving rhynchosaurs to suddenly see much of their food disappearing.

Lastly, that strange jaw arrangement made them have an inane grin on their faces at most times, which is probably why my students named one after me! They are also pot-bellied!

HIW: Could you talk about two or three dinosaurs that you find particularly interesting?

MB: The first one is what we call the Bristol dinosaur, which is a species called Thecodontosaurus. It was not a huge or particularly special dinosaur, but it was the fourth one ever to be named in the world, back in 1836, and it came from Bristol. With myself and Bristol University being here, we have latched onto Thecodontosaurus and now use it as a tool for a major education programme called the Bristol Dinosaur Project. So Thecodontosaurus was of modest size, bipedal and a planteater with a long thin neck and tail. It was a very modest dinosaur.

I suppose my second choice would have to be T-rex, as it was the biggest and most remarkable flesh-eating animal ever, and certainly the most impressive. Weighing something like five tons yet walking bipedally is incredibly interesting too, as it pushes the absolute limits of what is possible. I mean, you look at an elephant and think ‘wow that is amazing’, however, an elephant has to walk on four legs and weighs roughly the same amount, so understanding how T-rex functioned is a fascinating area of research.

Lastly, I will choose Microraptor. Microraptor was a small, flesh-eating dinosaur from China with feathers and the reason I am choosing it is because it is very close to the origin of birds. Its remains show it had wings on its arms and on its legs, so it was a four-winged creature. It couldn’t fly properly, however, but instead used its wings to glide. This shows us something that we simply did not know with Archeopteryx, and that is that the origin of flight in birds and their ancestors was much more complex and diverse than we ever expected.

On a dig site in Albuquerque, Mexico
On a dig site in Albuquerque, Mexico

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