Dr Stephen Brusatte - Tyrannosaur Discoveries

we're now going to go to totally it I'd like to welcome dr. Stephen Brewster she is not going to stand and they get standard the light Stevens a Chancellor's fellow in the school of Geoscience at the University of Edinburgh and he's a vertebrate paleontologist and he is an evolutionary biologist and he specializes in the anatomy genealogy and evolution of fossil vertebrates his particular research focuses dinosaurs but he also studies mammals crocodiles and other groups OB just no others other groups are amongst his specialists research subjects are the rise of dinosaurs to dominance during the Triassic period about 250 200 million years ago the evolution and genealogy of carnivorous dinosaurs the evolution of birds from carnivorous dinosaurs and then the extinction of dinosaurs that's used to pretty much cover dinosaurs actually doesn't know something that does it the beginning is why we're going under mammals and cracks he's written 78 peer-reviewed papers including 3 and science 2 in the Proceedings of the National Academy of Sciences he's the author of five books including the academic textbook dinosaur paleontology he's named over 15 new species of fossil vertebrate including four new species of tyrannosaurs and he's going to tell you what those names are because I'm not going to read them out so we'll get to that later he's undertaken field work in many places around the world including the western United States China Tibet UK Romania Portugal Poland and Lithuania his research is currently funded by the European Commission the Royal Society of London and the National Science Foundation in the u.s. Steve's got an undergraduate degree in tío physical sciences from the University of Chicago a master's in paleo biology from the University of Bristol and a PhD in Earth and Environmental Sciences from Columbia University in New York his research is frequently profiled by the popular press he often appears on radio and television and I was very interested to see the last thing I can tell you about Steve is that he's the resident paleontologist for the BBC's Walking with Dinosaurs program and was a scientific consultant on the 2013 blockbuster Walking with Dinosaurs 3d cinema release so would you join me in welcoming Steve all right if we have any time left we can talk about Tyrannis okay so how about this life I to tyrannosaurs this was great and hopefully I can follow up professor has his talk with something very different and that is one of my research focuses I think the most incredible amazing iconic dinosaurs of all tyrannosaurs t-rex and about 25 30 of its closest relatives meat-eating carnivorous dinosaurs that were around for a long period of time of course our thankfully extinct today but a group that we're learning more and more and more about every year so this is what I do for a living I study dinosaurs and other groups but particularly dinosaurs and it's an incredible time to study dinosaurs we now know of over 1200 different species of dinosaurs as you'll see a little bit later we are finding them at such an incredible pace right now and there were all kinds of dinosaurs that lived from the time that they originated about 240 230 million years ago until the time that most of them went extinct about 66 million years ago and here are just some of the the more familiar dinosaurs of all I get to do it here in Edinburgh which is great obviously you can tell from the way I talk I am NOT a native Scot I'm an adopted Scot but it's a great place to study paleontology there is such a legacy of paleontology at this university and in this country some of the most important fossils in the world come from Scotland not so many dinosaurs we're trying to change that but there's a long long legacy of people studying paleontology here so I'm it's been really great over the last couple of years to start building up my research group and become part of this history so alright enough about that so let's talk about Tyrannosaurus alright that's what we're here to do so this is t-rex I think we all know t-rex I think you could show this picture to almost anybody out on the street any kindergartner for sure and they would know it's t-rex this is the biggest baddest meanest dinosaur of all the biggest predator to ever live on land 13 metres long five or six one's size of a double-decker bus whatever hyperbole you want to use this was it tyrannosaurs are a group that really fascinate me I can't help but being fascinated by them they are my favorite dinosaurs it's a little bit cliched but I've worked on them quite a bit over the last ten years or so and I've been very privileged to be part of some excellent research teams that have been able to describe a name and discover four new tyrannosaurs these tyrannosaurs here when we're going to talk in particular later today about a couple of these pinocchio rex janja soros and alia ramos but we've also worked on a couple others and we have a few more that we're working on now because as you'll see we are learning so much more about tyrannosaurus literally every month a big part of my work has been not just to find new Tyrannosaurus and describe them but to study their genealogy and their evolution so a huge focus is putting together a family tree of Tyrannosaurus that's basically what I'm going to talk about today is how we fleshed out this family tree particularly over the last ten years or so and then when we have a family tree the reason we do this is the same reason why a lot of us I think build family trees for our own families we're interested in our history we want to know where we came from we want to know how our families changed over time how they moved around how our different ancestors got together and so that's the same reason we do this for fossils it helps us understand evolution because ultimately that's why fossils are important this is how we know about how evolution works over vast timescales millions and millions of years time scales we just can't observe today and tyrannosaurs are a great group for studying evolution because as we'll see there's a lot of them we're finding more and more of them we have a lot of really good fossils and of course they're very very popular they lived a long time great group to study alright so let's go to the beginning let's start telling this story from where it all began about a hundred years ago and this is when the first Tyrannosaur the most iconic Tyrannosaur of all t-rex was discovered so t-rex is only unknown for a little over a hundred years and much of the credit well some of the credit actually probably far too much of the credit goes to this guy here this very aristocratic looking gentleman very nice moustache like people had at that time Henry Fairfield Osberg very well-known paleontologist in New York at the American Museum where I did my PhD and where II and of our postdoc fellows did her PhD every day we'd walk in this entrance great place to work biggest dinosaur collection in the world a lot of that is because of this guy osburgh who got it started now he wasn't any old scientist he wasn't like you or me this guy had a father who owned a bunch of railroads he had more money than he knew what he could do with and he also unfortunately was not the most pleasant individual he was a rich white guy at a time when they had all kinds of interesting opinions so he was the president of the eugenics Society in the US he had some very intriguing racial views let's just say that he actually sent expeditions to Asia with the express purpose of trying to find the oldest humans to prove that humans didn't come from Africa not the nicest guy but a very prominent scientist not many scientists make the cover of Time magazine I guess professor has we've learned has been in Time magazine so maybe a few more actually can but this guy was on the cover because he was so well known president of the American Museum one of the most visible scientists in the u.s. now he didn't do a whole lot of field work himself but he was a paleontologist and he would send people out into the field to collect dinosaurs for him and so during the turn of the last century around 1900 he started to send out people to the western US to some of the best places in the world to find dinosaur bones in particular to the state of Montana way up there in the northwestern corner of the US and he sent this guy out there a guy with the really funny name of Barnum brown actually named after the circus guy PT Barnum Barnum Brown was one of the most unusual colorful people in the whole history of paleontology one of the greatest fossil hunters that ever lived a guy with a nose for fossils he found some of the best-known dinosaurs ever but a strange guy he would do field work in the summer in a mink coat why not not hot enough in Montana he he was a spy during both world wars he worked for oil companies and actually was quite a bit of sabotage when he was out looking for fossils he find fossils by day and steal information and even sometimes destroy oil wells by night interesting character he has offspring all over the American West apparently but a great fossil hunter maybe even one of the best fossil hunters of all time and in about 1902 he was sent out by Osbourne to Montana to find dinosaurs and he found a dinosaur an incredible dinosaur this dinosaur which immediately made headlines and a few years later Osburn described it in this publication and called it tyrannosaurus rex the tyrant dinosaur king the biggest predatory dinosaur that had ever been found and this did cause a sensation at the time because no other dinosaur at all like this had been discovered there had been smaller meat-eaters that had been found but nothing quite of this size that's why he gave it this dramatic name t-rex came from right at the end of the Cretaceous 66 67 million years old they didn't quite know that at the time we now know that because we have more precise radiometric dating of rocks but this was one of the last surviving dinosaurs of all this was a dinosaur that actually would have witnessed the asteroid impact that knocked off most of the dinosaurs 66 million years ago so t-rex the sensational dinosaur that Brown found that Osburn described amazing dinosaur but one of the last surviving ones of all and dinosaurs as I mentioned originated long time before so t-rex was really just kind of part of the end game of dinosaurs and so this led to a lot of questions we didn't know nearly as much about dinosaurs back then as we do now but of course people wanted to know where did this incredible 13 meter long 5 ton dinosaur come from what did it evolve from did they live earlier in time nobody knew all we had was this Colossus right from the end of the Cretaceous over the next 75 years or so people started to find more as we do all the time in paleontology people fanned out around the world and new tyrannosaurs were found but all of these tyrannosaurs were pretty similar to t-rex none of them were quite as big but these were all fairly large predators that lived right at the end of the age of dinosaurs and many of these are from North America albertasaurus of course named after Alberta in Canada Gorgosaurus des fleeta soros then people found some in Asia this is Tarbosaurus the closest relative of t-rex lived in China and Mongolia when t-rex lived in Asia so people over the course of the 20th century started to learn more about tyrannosaurs started to figure out that they were a more diverse group than just this one wacky oddball t-rex but we didn't really know that much really all that we knew adding to this picture was that there were a bunch of big predators living in North America and Asia at the end of the Cretaceous we didn't know much about where they came from how they evolved how they changed over time how they achieved such gigantic size we literally really had no idea until very recently up until about 2000 so really just 15 years ago so this is what the family tree of tyrannosaurs looked like we knew we had t-rex we knew we had some of these other big guys living at the end of the Cretaceous we had other dinosaurs and this was pretty much it that is what the family tree of Tyrannosaurus looked like at about the time that I entered high school so we didn't really know that much at all but things have changed things have really changed and things are changing fast and they continue to change because we are in the Golden Age of dinosaur discovery these are just a few headlines from the last six months people right now are finding a new species of dinosaur somewhere around the world on average of once a week so about 50 new species of dinosaur every year and that's not new fossils that's not a new bone or new skeleton that's a totally new type of dinosaur that we never knew before so the pace of discovery is tremendous and a lot of these new dinosaurs are tyrannosaurs and so these new discoveries have told us a whole lot they have really helped us piece together the family tree of Tyrannosaurus and understand the evolution of Tyrannosaurus one of the things they tell us is where Tyrannosaurus fit in with all the other dinosaurs where they fit on the dinosaur family tree and it may surprise you but actually birds of course are dinosaurs some of you may may know of this many many feathered dinosaurs we'll talk about this a little bit later birds are dinosaurs very peculiar living dinosaurs that can fly and Tyrannosaurus actually are fairly close relatives to birds they're not too far away they're more closely related to birds than to almost any other type of dinosaur amazing so t-rex really wasn't some overgrown crocodile or lizard it was a very bird-like animal and we didn't really know this until these new discoveries over the past 15 years but the other thing that these discoveries really allow us to do is finally flesh out this family tree of tyrannosaurs and tell the story of how they evolved and it turns out to be a fascinating story a very rich story and I think a very unexpected story and so what I'm going to do for in this talk is take you to three places where three very important new tyrannosaurs have been found as well as some other tyrannosaurs alongside them these are Russia Mongolia and China now there are other tyrannosaurs still coming out of the US and Canada there's even some tyrannosaurs in Europe there are tyrannosaurs that have been found in England there are a few species and we even have a few bones from middle Jurassic about 170 million years ago from Scotland from the Isle of Skye that are probably very early tyrannosaurs but I'm not going to really talk about those because I want to be a little bit more exotic and take you a little bit further afield so let's go to Asia and let's start building up this story of tyrannosaurs and their evolutionary history so let's go to Russia first this very small region of Russia Siberia a very important dinosaur was discovered less than five years ago it was discovered by this guy who smiling next to Sasha a varieties one of Russia's most senior paleontologists they actually works more on mammals and on dinosaurs he's an expert on those mammals that were living alongside the dinosaurs but when he's screen washing to find his tiny little mammal teeth occasionally he also finds a dinosaur so he has to study the dinosaur poor guy and so when he was working with his team about five years ago in Siberia they discovered and very interesting specimen there's not a whole lot of it only a few bones from the skull there's a few more bones of the lower jaw that aren't shown here they were found later there's a few bones of the neck and parts of the rest of the skeleton not a whole lot but very clearly a new type of dinosaur very clearly a meat-eating dinosaur and very clearly a Tyrannosaur but an old Tyrannosaur about a hundred and sixty-seven million years old a hundred million years older than t-rex this is the oldest Tyrannosaur that we know about and it's very different looking from t-rex I think that's pretty obvious it's a lot smaller than t-rex for one it's only about the size of a human and it doesn't have that big toothy skull of t-rex it has a much more delicate skull with the base of this very strange crest now you can't really see most of the crest here but we know it has a crest because a couple of other very close relatives of this cholesky this Russian Tyrannosaur have also been found very recently one in China with a huge crest and there's a lot of bones of this guy is called guanlong also just about human-sized and then once guanlong was found and showed that you had tyrannosaurs at this very early age and they had these weird crests people went back to look at museum collections and people noticed in the Natural History Museum in London this specimen called crow Ceratosaurus discovered in 1910 only a few years after t-rex nobody knew what it was nobody even thought it was a Tyrannosaur it was so much older than t-rex it looked nothing like t-rex at least to the naked eye but when guanlong was found it was something of a rosetta stone and immediately people noticed the similarity so we know that some of the earliest tyrannosaurs also were living in england so it looks like we had these early tyrannosaurs a hundred million years before t-rex in russia in china in england probably a globally distributed group but these were not very big animals these were not dominant animals these were not animals at the top of the food chain they were living in the shadow of other big predatory dinosaurs so not very impressive dinosaurs these were they probably looked something like this you'll notice very fuzzy this dinosaur we'll talk about that in a minute but this this is basically where t-rex came from interesting looking animal but I don't think if you looked at this guy you would really ever draw a parallel to t-rex I don't think you would ever predict that a hundred million years down the line that basically this kind of thing would evolve into a 13 meter long 5 ton top of the food chain killing machine but that is what evolution did so we can start now to put together this timeline in this family tree of tyrannosaurs and this is what we saw before again this is all we really knew up until about the year 2000 but now we can add in that tyrannosaurs evolved at least a hundred million years before t-rex has very different types of animals small fast running not top of the food chain dinosaurs and we can add these to the family tree and we can see that there's these weird ones small ones with these crests very early on that our tyrannosaurs and I just say we know they're tyrannosaurs because they share features of the skeleton that are only seen in t-rex they might be subtle things you might not notice them immediately but there are many features in common including of this throughout one the bones of the snout are fused together in tier X and another tyrannosaurs they're also fused together in these dinosaurs you don't see that in other dinosaurs that's one of many features that tells us that although these things don't look a whole lot like t-rex they are Tyrannosaurus so we're starting to build up the family tree here and let's keep adding to it now let's go to China now to this corner of northeastern China Kalyanam province this is part of Manchuria tortured history over the last few hundred years shares a border with North Korea interesting place not a place that Taurus really ever get to although it's not too far from Beijing Beijing just over here I was there last week this I took this photo a week ago week ago last Thursday from the Train this is what it looks like in the countryside there again it's not the prettiest place in the world very industrial also a lot of rolling hills and a lot of farmland this is all farmland out there there's even some fields here we barley but especially corn has grown in this area and this is a place that in addition to having a lot of Industry and a lot of farmland is also a place that now produces what are probably the most incredible dinosaur fossils from anywhere in the world and one of these is a new Tyrannosaur described just two years ago called you Tyrannis we'll get to you Tyrannis in a second but the reason why you Tyrannis is so interesting i mean it's a new Tyrannosaur that's interesting enough but is interesting because it has feathers on it but that doesn't make you Tyrannis unique in fact we now have thousands of fossils of die sores covered in feathers from this area in Leone and these are the primary evidence that dinosaurs were the ancestors of birds that living birds came from dinosaurs we only have dinosaurs with feathers but we have dinosaurs with wings there's a dinosaur with the wing incredible and very rare to get this kind of preservation you can't just preserve feathers everywhere these feathers are preserved because this area was full of volcanoes 125 million years ago they would occasionally erupt and Pompey style would bury entire dinosaur ecosystems preserving everything as a snapshot and burying everything so quickly that even the soft bits like the feathers would get preserved usually those decay away but here we're lucky that we have them and here where we get that kind of preservation we see that almost every type of dinosaur has some kind of feather some have these very quillpen type feathers like living Birds others have simpler feathers that look a lot more like hair one of these is you Tyrannis people are finding new fossils of these feathered dinosaurs every day and they're not really scientists that are finding the fossils in fact scientists don't even know where a lot of the best sites are it's farmers farmers working the land that find these fossils and sell them to museums and this is a museum the jinjo Museum where I was last week and this is one of five storerooms that they have full of dinosaurs with feathers shelf after shelf after shelf after shelf I can't tell you how many new species I just saw walking through incredible incredible and literally every day farmers are finding new ones this is a big part of the research I'm doing we have a big collaboration with workers in China and so the reason I was there last week was to work on this guy this is a new feathered dinosaur a very close relative of velociraptor and so this is something we're working on now and hopefully we'll we'll be able to come out with this in a few months or so all goes well one of the guys I work with in China is this chap here shushing is his name probably the most famous dinosaur hunter in China right now he's one of the leaders at the Institute of vertebrate paleontology and paleoanthropology in Beijing and he has studied many of these feathered dinosaurs including this one here is called Microraptor it's a Velociraptor type animal with big feathers all over its arms and its legs one incredible dinosaur but not a Tyrannosaur a couple years ago Xu and his team worked on these fossils that they got from a farmer as probably doesn't look like much so you can see probably some bones here and there maybe you can see these jaws up here with teeth this is a new Tyrannosaur which they called you Tyrannis lived 125 million years ago and it's quite a bit bigger than those little crested ones that we saw from Russia and from England and from earlier in China this one's about 8 or 9 metres long about a ton and a half is what it would have weighed so nowhere near the size of t-rex but a much bigger animal tyrannosaurs were diversifying they were changing they were doing more things by this time about 40 million years or so after they originated this is the skull really really nice preservation and there's multiple individuals these look like they were social animals they live together just like many birds do today but the great thing about you Tyrannis is as I mentioned it is covered in feathers feathers that looked a lot like hair so basically this would have been a big fluff ball all over its body too not just a mohawk on its back or a little bit around its head or a little bit on the arms all over the body this thing was covered in feathers and it's not the only feathered Tyrannosaur from those rocks and leaning province there's another one called D long that was actually found a few years earlier and this is a much smaller Tyrannosaur tiny just about the size of a terrier really and it is also covered in feathers beautiful feathers here are some of the feathers these are a couple of the tail bones individual vertebrae of the tail and these things that look like scratches up on the top those are feathers simple feathers feathers that look like hair this is what the feathers of birds today with vanes the quill pen type feathers this is what they evolved from but these early dinosaurs had bodies covered in these types of feathers so this is really leading to a total re-imagination of what tyrannosaurs looked like this give or take is probably what t-rex would have looked like we don't have any feathers preserved in t-rex because in Montana these places where Barnum brown found his fossils you didn't have volcanoes burying entire ecosystem so feathers decayed skin muscles all that stuff decayed but if we had to guess I think we would guess at something like this because we know that other tyrannosaurs close relatives of t-rex had feathers of this kind so this famous fight scene between t-rex and Triceratops that you see in Jurassic Park and you see in museum exhibits and basically every kid's book it probably looked a little bit more like this and even the Triceratops probably had some kind of feathers incredible so these things were big fur balls big fluffy monsters big birds from hell whatever you want to call them a different vision of t-rex than we think and you won't see this in the new Jurassic Park because they won't put feathers on it because they think people you know don't want to see him with feathers and you know maybe they're true because when the first Jurassic Park came out 1993 those feathered dinosaurs weren't known those feathered dinosaurs were only first found in 1997 so less than 20 years ago until then we'd had never found a dinosaur with feathers now we have thousands so this is helping build up this Tyrannosaur evolutionary story even more we can now add in that by kind of the early part of the Cretaceous 125 million years ago or so you had other tyrannosaurs some of them were larger like you Tyrannis some of them though actually most of them were still small and they were covered in feathers and we can put them into the family tree and see that they kind of fall out around here so intermediate kind of between those very the primitive ones and the big t-rex like ones from the end of the Cretaceous but our story in China doesn't stop there because of course I have to talk about Pinocchio Rex which is one of our new discoveries that we announced earlier this year and Pinocchio Rex comes from a lot younger rocks so rocks that are much closer in age to the present it's about 66 67 million years old and it comes from farther south and taught in China near a city called Gallo and it was here in 2010 at this site so I'm standing here with my colleague Yoon Kang Liu another one of my very good friends and co-workers in China he was also in the photo where we were studying that dromaeosaurus or with feathers at the museum and Liang but here we are in southern China at basically what is a big building site looks to be that way because that's what it is there's a building boom all across China especially in this area new buildings are going up everywhere and they just so happen here when they're building these buildings this isn't soil this is actually ground-up mud stone or shale this is rock and this is rock that is about 66 or 67 million years old in this rock this full of dinosaur bone so in 2010 one of the workers was working his digger his backhoe and hit something hard which normally is a bad thing if you're building a building and you run into something hard but they went down they feared the worst they thought the backhoe was broken or that they you know ran into some bedrock or something like that they cleared it away and they found that oh no nothing to worry about just a complete skeleton of a Tyrannosaur just another day at work actually it is kind of just another day at work in this part of China because there are many dinosaurs that they're finding they're finding a lot of these very small bird-like dinosaurs they're finding big long-necked dinosaurs they're even finding lizards and lots of dinosaur eggs in these same rocks so full of dinosaurs so really every day they basically do find dinosaur bones but this day they happen to find a complete skeleton of a Tyrannosaur and luckily it made its way into this museum the gonzo museum and there's an incredible story here because well that Tyrannosaur was found as we saw earlier 7.3 billion mobile phones in the world all those workmen started to call people and within 30 minutes people from the museum had come but also some poachers some black-market fossil dealers it's a big problem a lot of fossils from China you might see online on eBay and Rock shops these are illegal you can't take fossils out of China but there's a booming underground trade and it was literally minutes that separated this fossil from being sold and going to the museum but luckily it went into the museum amazing museum this is one of the storerooms is like the size of an airplane hangar this is Pinocchio Rex here an 8 or 9 meter long dinosaur and all of these are dinosaur nests eggs of different kinds of dinosaurs they have tens of thousands of dinosaur eggs in their collection so an incredible place to work but more interesting than the eggs is certainly the skeleton of this Tyrannosaur and it's an amazing skeleton we have basically the entire skull the teeth aren't preserved it didn't have a beak or anything wasn't a beak Tyrannosaur anything like that the teeth have fallen out but almost all other parts of the skull are there as well as most of the rest of the skeleton here's the neck here's part of the tail these are a couple of bones of the legs and so we have nearly a complete skeleton we can tell that this thing was probably about eight or nine meters long probably weighed a few tons not quite t-rex eyes but a decent-sized animal but it wasn't fully grown it was a teenager when it died we think it looks something like this and what really stands out is it has this long skull this long snout that's why we gave it this cheeky little pinocchio nickname because this proper scientific name janja soros and correct me if i'm mispronouncing it's very difficult to say i've been corrected many many times so we thought a nickname would be in order so because it has this long skull we called it Pinocchio Rex and this long skull really sets it apart from almost all other tyrannosaurs t-rex doesn't have a skull like that t-rex has a skull that's much shorter much deeper very robust very schooler not Pinocchio Rex and Pinocchio Rex also has a bunch of little horns on top of its skull not like the horns of Triceratops but kind of little bumps and this is also very unusual so this is a strange Tyrannosaur but very obviously a Tyrannosaur and this is a reconstruction that we had a really really good artist in China do a little bit psychedelic rainbow colors maybe could be we don't know but this is basically what we think it was it was a big bloodthirsty predatory dinosaur but probably not at the top of the food chain it probably ate small lizards and some of these small feathered dinosaurs but it actually lived alongside these Tarbosaurus dinosaurs the Asian version of t-rex the 13 metre long five or six tonnes one so this was a Tyrannosaur that was eight or nine metres long weighed over a ton but wasn't even the top predator in this ecosystem and it wasn't only China where you had these strange long-snouted tyrannosaurs so it turns out there's a few other fossils of long-snouted tyrannosaurs and these have been mysterious for a long time this is one called Elia Ramos remotest this is just a drawing of a few bones there's part of the upper jaw part of the snout some of the lower jaw now much of it is known it was discovered in Mongolia it was discovered in the 70s back during that time when we didn't know much about tyrannosaurs now if people were able to interpret this right at the time they actually would have learned something really unexpected about tyrannosaurs but for various reasons the specimen wasn't very accessible to researchers other political issues it's in the collection in Russia you can imagine what may have happened in the 70s in the 80s when people would want to study the specimen so it was out there it was described in a Russian paper but nobody really got to look at it so people knew it was a Tyrannosaur and could tell it was a little bit different from t-rex seem to have a longer snout but we really didn't know what to make of it well that was until 2009 and in the Gobi Desert of Mongolia a new Tyrannosaur was named and this was from a team that was led by this guy here dapper looking fellow Andy Warhol look-alike mark Norell who is my PhD advisor and also E's in New York very eminent paleontologist one of the world's great dinosaur experts and for over 20 years he has been leading a team a joint American Mongolian team that every year goes to the Gobi Desert one of the best places in the world to find dinosaurs and finds new dinosaurs digs him up and so in 2001 somebody came across this this jaw bone sticking out of the rock Tyrannosaur bone and so they took it out of the ground and over the next few years took it back to the lab and prepared it very carefully took the bone out of the rock and it turned out that this was a beautiful specimen a nearly complete skull but unlike pinocchio rex all of the bones are separated great brain case these are the bones that surround the brain protect the brain in the sense organs much of the rest of the skeleton the neck the back the hind legs a huge amount of material and putting it all together the skull looks something like this very unusual long-snouted it looks like Pinocchio Rex of course Pinocchio Rex came a few years later so we didn't know about Pinocchio Rex at the time but a very similar dinosaur it turns out to be a very close relative of Pinocchio Rex but it's a new species and we call this a Leah Ramos LT and this is basically what his skeleton looks like again these dinosaurs were not quite t-rex in size they were eight or nine metres long weighed one or two tonnes living alongside the bigger tyrannosaurs so huge dinosaurs but not apex predators we have studied this skeleton in gruesome detail as we like to do we love bones so he studied a lot of bones and we use whatever technology we can so one of the things we did here was we used a cat scanning to look inside those bones that surround the brain to get a look at what the brain would have looked like and so this is basic the model that was reconstructed these are all different sinuses this is the brain if we just look at the brain here this is what the brain of a Tyrannosaur would have looked like and there's the ear the inner ear these are the different nerves coming out so this is just just kind of a taster of so you can see how paleontologists are really using very sophisticated tools these days and this is something that basically all of my students are starting to use and E is a very very high level user of CT scanning so she's working on lizards and snakes using this technology here anyway so it's not just finding bones and studying bones but we're using a lot of new technology just a taster so these long-snouted tyrannosaurs then they add more complexity they help flesh out the family tree even more because now they tell us that during the very end of the age of dinosaurs 66 67 68 million years ago when t-rex was dominant in North America when Tarbosaurus this Asian version of t-rex was at the top of the food chain in Asia you also had some weird tyrannosaurs with long snouts second tier predators so you had diverse ecosystems with tyrannosaurs filling different roles tyrannosaurs weren't just top guns even at the very end of the age of dinosaurs and so we can add these into the family tree and we can put them up here we actually see that they're very close relatives of t-rex although they look a bit different that's because they kind of went on their own little evolutionary path they're actually very very close relatives of t-rex and so this is basically where the Tyrannosaur family tree stands right now this is a simplified version we have about 30 different species now so much greater than those five or six species we had only 15 years ago and we could add in all the little twigs and it wouldn't look so pretty as a as a slide but basically this is in general what the family tree looks like we have a lot of new tyrannosaurs from all over the world many that I wasn't able to talk about and of course now that we have this ever-growing family tree we can have fun with it we can use it to study evolution just really what we enjoy doing and so what then is the evolutionary story of tyrannosaurs where did t-rex come from well this is how the story is looking now tyrannosaurids were very diverse very long evolutionary history this wasn't just t-rex living at the end of the age of dinosaurs Tyrannosaurus were so much more than that they originated more than a hundred million years before t-rex lived they are an ancient group of dinosaurs we almost certainly had them in Scotland when these fossil bearing rocks on the Isle of Skye were laid down it's only a matter of time maybe the next time we go up the sky we'll find a Scottish Tyrannosaur it should be incredible they're a very very very old group with a rich history but for most of that history the first 80 million years or so they were not very special they weren't dominant animals they weren't at the top of the food chain most of them were human sized fast runners probably feeding on small prey living in the shadow of other types of dinosaurs that were at the top of the food chain more primitive dinosaurs that were the top predators sure there were a few tyrannosaurs like that big fuzzy you Tyrannis from China that were a little bit bigger but nothing like the size of t-rex so 80% or more of the history of tyrannosaurs there wasn't really that much to and they were doing well they were living all over the place they were diverse they were evolving but they were not dominant in any sense of the word they only became these colossal apex predators at the very very very very end of the time of dinosaurs only about 20 million years before that asteroid hit did tyrannosaurs become huge and become at the top of the food chain and only in North America and Asia by the way there were no tyrannosaurs in europe at that time there were no tyrannosaurs and the Southern Cotton's of that time so really tyrannosaurs were a pretty localized group but in those local regions they were the top dogs they were apex predators and they were doing very well until one day one Tuesday morning or Wednesday morning or whatever morning something 10 kilometers wide fell out of the sky smashed into Mexico what is now Mexico and wiped out all of the dinosaurs except for birds so the reign of tyrannosaurs came to a very sudden very abrupt very unexpected end so I think Tyrannosaurus tell us something very interesting about evolution for most of their history they weren't very special you would have never predicted back 170 million years ago that they would evolve into something like t-rex and then t-rex came into being it evolved it became a top predator and then BAM one day it was wiped out and really I think this is how evolution works nothing predestined us nothing preordained you never know what paths evolution is going to take so even something as incredible as iconic as dynamic as amazing as t-rex was really just kind of a tip of the iceberg of this long history of a group that had been pretty pathetic for a long time and then it was struck down in his prime but that's why we're here that's why mammals had our chance to diversify so with that thank you for paying attention to Tyrannosaurus and of course I'm very happy to take any questions that you have I'm not sure if it's still accepted that structures that look the same kind of had completely separate eeveelution Airy origins like the octopus I'm the mammalian I I'm just wondering how we know that things that look look like feathers on dinosaur and fossils have got anything to do with things that we call feathers on birds yeah so it depends on which feathers you're talking about think anybody would debate anything about these quill pen type photos you have dinosaurs like Velociraptor type dinosaurs that had wings with feathers it looks like you could just pluck one off and start writing with it so there's no question about those the ones with hair the hairy looking feathers you know maybe you could have a question about that they don't look a lot like feathers today well they kind but they actually kind of do birds have lots of different kinds of feathers and there are very simple feathers down feathers and other types in birds today that are very very similar to those simple hair like feathers there's also things you can do developmentally you can tweak the DNA of birds and make them grow these very simple feathers and with the fossil feathers you can look at their microstructure under the microscope and you can find that they have the same structure basically internally as bird feathers do today so that is is kind of the nutshell of why we're pretty confident that these things are absolutely feathers you mentioned something about all these dinosaurs in different places around the world but the world was very different 100 million years ago what you know what does that have to do with the interplay of the distribution of the different species and yeah yeah well when tyrannosaurus first originated 170 million years ago or so the continents were much closer together you know this wasn't Pangaea time Pangaea had started to split up before but most of the continents were still connected which is probably why these tyrannosaurs lived everywhere by 66 million years ago the continents basically look like they do today which is probably why you only had tyrannosaurs in certain parts of the world North America and Asia at that time so there's no question that the drifting continents played a big role in how tyrannosaurs were distributed and probably were a major driver of the revolution as well birds have a very distinctive breathing system very very distinct from lizards or mammals do we have any evidence of how dinosaurs breathed did they have a bird type system and this is have any explanatory power over their eyes yes is the answer to that question yes and yes we do know how they breathed at least generally and they did have a bird-like system and we know that because the respiratory system leaves marks on the bones so birds have a long a very efficient type of lung that's uni-directional and I probably need an engineer to explain it but the way it works is oxygen actually goes across the tissues of the lung both when the bird breathes in and when it breathes out and there's a system of air sacs that basically shunt air to different parts of the body that allow that to happen those air sacs invade the bones they need places to go in the skeleton and so we see in living Birds where those air sacs go into bones we see what that looks like we see the holes in the bones very characteristic size and shape and distribution and placement we see the same things in not all dinosaurs but basically all of the carnivorous dinosaurs and also the long neck dinosaur so t-rex we have its bones it has those marks where those air sacs go into the bones it would have had a bird-like lung which is incredible I was just wondering could you explain how it is the event in Mexico wait to the dinosaurs ah with pleasure yes so this is me glad to assess but I think this is one of the things that you know we've been studying and we had a new study come out a few months ago where we took a fresh look at this question because there is a lot of debate we know an asteroid or a comet one or the other hit 66 million years ago no question we have a crater all kinds of other evidence but there has been a question about whether that killed off the dinosaurs or whether maybe this was a coincidence and dinosaurs are on their way out anyway a lot of different thoughts hard to test of course because this was a long time ago and the fossil record is very biased but one thing that we can do in which we did was look at evolution trends and dinosaurs over time especially over the last 20 million years or so of the Cretaceous period using all you know the most updated records of dinosaurs again we're finding so many new ones every year that our datasets getting better and better but also we have a lot more sophisticated techniques now statistical techniques to look at evolutionary trends to take into account biases in the fossil record and so we did this this very updated analysis and we found absolutely no evidence for any kind of long term declines or anything like that dinosaurs were doing well when the asteroid hit but there's a little bit of a twist in that during the last few million years before the asteroid hit just a few million years a few groups of dinosaurs were kind of waning a little bit in their diversity and those were the big plant eaters those were the horned dinosaurs the duck-billed dinosaurs the base of the food chain dinosaurs so it looks like and some ecological modeling has suggested this it looks like those ecosystems with fewer big plant eaters at the base of the food chain were a bit more susceptible to collapse if something happened and so it just so happened that that's what those ecosystems were when the asteroid hit if the asteroid hit a few million years earlier maybe it wouldn't have been so severe if it hit a few million years later when those dinosaurs surely would have recovered their diversity as they always had for 150 million years maybe they would have been in a better position to survive so the asteroid did it no doubt it was sudden no doubt but this very short term diversity decline of just a few types of dinosaurs seems like it made their ecosystems a little bit more vulnerable and probably made that asteroid even more serious when it hit I don't know wish we to ask this question but why did some dinosaurs get so big or why have mammals not so big because mammals at the top of the food chain carnivorous mammals are nothing like as big as these very large dinosaurs and have there always been very large dinosaurs of the size of Tyrannosaurus same time they've been small ones yeah so this is one of those questions about dinosaurs that we are always wondering about how some of them get so big because some of these dinosaurs are just totally out of the range of anything alive today a t-rex would be one I mean the biggest predator today is a polar bear which is big you wouldn't want to run into one but it's nothing like a t-rex but not to mention the big plant eating dinosaur is the big long neck one some of these things probably weighed 70 or 80 tons and were 35 40 meters long nothing like that today so there's a lot of research on this there's a lot of competing ideas but I think it was probably a cocktail of things that allowed dinosaurs to get so big their biology was probably part of it they probably were not quite as warm blooded as living mammals so they didn't probably need as much in terms of resources and food they could grow pretty fast as well it could grow faster than a lot of mammals today or very least kind of a similar rate so they were able to get big fast you're living in a world that was much warmer there's more oxygen all kinds of things like this so it was probably a number of things that allowed them to get big and also the lungs may be an important part of this story because those air sacs can hollow out bones and actually save a lot of weight in the skeleton mammals can't do that we have sinuses in our skulls but we can't reduce weight in the rest of our skeleton by sending air sacs into our vertebrae and into our femurs and stuff so this actually may have been something that you know might not think of maybe a trivial little thing but it could have been a very important part of that cocktail so I think the the short answer is it was probably a lot of things that combined both biological things and also environmental things that allow dinosaurs just to do things very differently than mammals thank you Steve I don't think I've ever been numb to a lecture about dinosaurs it's heard them described as big fluffy monsters before it's put a whole different take on dinosaurs for whatever I remember that in your nightmare I will I will but you have your absolute enthusiasm for your subject has shown through tonight and you said we were in a golden age of dinosaur discovery and you obviously relish Sigma and you've really shared your passion enthusiasm with us I'd like to ask everybody to thank don't steal it

Channel: The University of Edinburgh

Views: 58,617

Rating: 4.7088609 out of 5

Keywords: Tyrannosaur (Film), Stephen L. Brusatte, Dinosaur (Character Species), Paleontology (Field Of Study), Tyrannosaurus (Organism Classification), Tyrannosaurus rex, T.rex

Id: hVJmPmb_LWY

Length: 52min 56sec (3176 seconds)

Published: Fri Feb 20 2015