Sauropods: Titans of the Mesozoic

good morning everybody welcome to the 20/20 edition of the royal trio museum speaker series today the Royal Trail Museum and it's cooperating Society are proud to present mr. Kerry Woodruff Kerry is currently a PhD candidate at the University of Toronto he's originally from the town of bumpass in Virginia in the United States and he obtained his BSC in Earth Sciences at Montana State University in Bozeman in Montana or his senior undergraduate thesis Kerry conducted an actual istic taphonomy experiment on the first burrowing dinosaur the small ornithopod oryctodromeus and for his master's Kerry decided to stay at Montana State University where he studied the ontogeny and development and life history of diploid osted sauropods after completing his master's he moved to Canada to begin his PhD in the Department of ecology and evolutionary biology at the University of Toronto for his dissertation Kerry is investigating the evolution kinematics and life history of North American pachycephalosaurs the dome headed dinosaurs Kerry is truly passionate about sauropods which are the long necked dinosaurs and he's interested in many other aspects and many other research topics as well including taphonomy histology Stegosaurus and cersei and dinosaurs just name a few he is currently the director of paleontology at the Great Plains dinosaur museum in Malta Montana or he conducts fieldwork every summer today Kerry is talking about sauropods the Giants of the Mesozoic so without further delay I present mr. Kerry Woodruff [Applause] good morning I hope everyone can hear me if I'm not loud enough just like this I'll try talking louder I'm I had a cold a couple weeks ago and it's ravaged my throat so I'm just sound like a 40 year smoker of a please pardon that theropods represent some of our most classic and iconic of dinosaurs often referred to as the cereal box time and especially for the public when they think of the word dinosaur a lot of times just a mental image of the body plan of a sauropod comes to mind and so sauropods have basically ever since their discovery have always graced the public's perception of dinosaurs and this ranges from the logo of Sinclair oil which of course actually has to get its history because of paleontology expeditions digging up sauropods in the American West and a business relationship with that of course the very first that animation ever was Gertie the dinosaur Fogerty the sauropod and of course the numerous forms of popular media such as Littlefoot from The Land Before Time and even the crate dragon of the first Star Wars film was a cast of the Diplodocus Carnegie Carnegie a hollow Titan but what really captivates us about sauropods collectively is their scale I mean they are truly Titanic beings so we think that animals like dinosaurs like Tyrannosaurus and Triceratops were large and they certainly are jalaw are large animals when compared to a human but for the dinosaurs scale sauropods are hands-down the largest of all dinosaurs significantly larger and this isn't just one or two sauropods that were particularly Titanic for their entire evolutionary history on earth the majority of sauropods are recorded and dominated by these truly titanic animals and of course we don't we've never had any other group of animals walking around on earth since sauropods are after that even come close to achieving their proportions so they're incredibly fascinating animals and in fact the largest sauropod that we know of to date and of course it's always a debate what's the largest sauropod are we talking about mass are we talking about length and this is hard we don't find them complete but the sort of clear winner of recent is this monster how to get Titan from South America it's estimated to have been about 130 feet long give or take you can see beautiful life-size casts of it at the Field Museum of Chicago and the American Museum of Natural History and over here on the right this is one of the discoverers of Pataca Titan at Diego pole with the femur and that femur is eight feet on the dot I think second to the skull of you know Torosaurus just the you know skeletal immature Triceratops that's you know single-handedly the largest bone that you know a limb bone at least we know of from a dinosaur table and again of course compared to Taurus versus you know one of the largest just dinosaur bones we have in general but there are a lot of sort of misconceptions I think with sauropods a lot of their history and things we sort of gloss over or sort of perpetuate that aren't necessarily factual so throughout the course of the lecture today I want to try to not only clarify some of these points but go into some aspects of sauropod paleobiology that I think make them incredibly special animals so the first popular perception that I always like to squish is there's sort of a narrative that sauropods have their heyday in the Jurassic they kick the bucket in the lake Jurassic and of course it's because of this absence of sauropods that hadrosaurs and ceratopsians are able to dominate throughout the Cretaceous and this narrative is only partially true if you are in East Asia and North America but if you look at the rest of the world throughout the Mesozoic there is an entire history of sauropods that dominate the record as eat dominant terrestrial herbivores so again go anywhere else in the world throughout the Mesozoic and you find a dinosaur odds are it's probably going to be a sauropod so they've really had a worldwide domination and especially on the market for terrestrial herbivores and you can go again anywhere in the world and find sauropods I'm a little biased I think the American West has the best record of sauropods that we can find and you can go to places like Dinosaur National Monument in Vernal Utah and you can just these beautiful death assemblages of nearly complete to complete sauropods together there is actually a sauropod record in Canada it is at least as of published now noon just from tracks but there is actually the very first body fossil of a sauropod from Canada that's currently being described so they were up here too contrary to again popular perception that they weren't here in Canada people also think that all sauropods are big and again their evolutionary history is dominated by being big but they certainly didn't start out being big the earliest sauropods which are also some of our earliest dinosaurs that we know of on earth were small and bipedal like here this is Saturnalia so not only were they small and bipedal and note the small four limbs the earliest sauropods were also carnivores so sauropods that ate meat and it's only shortly into their evolutionary history that they decide plants are kind of a good route to take for the rest of their history but for those of us who study sauropod paleo biology the majority of our questions again are sighs focused and dedicated to being big now I can't go into all of it today but you simply cannot take let's just say for instance we took a mouse and blow up a mouse to be the size of an elephant so biomechanics does not work that way you can't just simply make an animal bigger and so sauropods have an entire evolutionary history that time and time again is documented by the bioengineering that goes on to being thick so some of the questions that a sauropod paleo biologists are looking at is some sort of pods like the mint resource of a neck that's 17 meters long so you can imagine not only is that neck 17 meter in of the bones and the next 17 meters so is the trachea so imagine breathing in and out of the tube 17 meters how the heck do you not pass out in between breaths right with some sauropods weighing in excess of 50 tons how is not only the skeleton but the muscle form the muscles designed to be able to maintain that weight even through locomotion so how do you move when you're that big what's the soft tissue engineering that goes into that of course again wait related all they were eating at least these more you know advanced or you know derived sauropods are eating plants how the heck do you get to be fifty tons by just eating plants and compared to today's standards a lot of them are very low nutrient quality plants so how the heck did they get to be so big and so generally when we're looking at and trying to make physiological inferences from dinosaurs we use a method called the extant phylogenetic bracket so we compare a dinosaur we bracket it between their closest living relatives today so crocodilians and birds so just for an example let's say we didn't know dinosaurs laid eggs crocodilians lay eggs bird lay eggs therefore dinosaurs probably laid eggs as well check mark but there's many aspects of the sauropod their collective biology that really makes an EP be level approach incredibly difficult if not impossible they had parental care more like a crocodile they had respiration more like a bird but they had a stance unlike that that we see in crocodilians and birds they have we have evidence of muscles and soft tissues that are different from both birds and crocodiles and again it's their extreme size that is so different so we can't necessarily make these direct comparisons so it can be really hard to try to understand from this approach aspects of sauropod paleobiology but that doesn't mean that we can't do it nonetheless we just have to be a lot more I think I can say more innovative in our approaches to questioning sauropod physio physiology so today just two aspects and I mean I've even done whole short courses on sauropods so you're getting the incompletely abridged version um but just two of the things I think about their overall biology that are fascinating are the necks and what they actually did with their necks and of course their life history so of course let's dive into the sex east end of the sauropod the neck that's received the most attention if we look at sauropods in the Morrison Formation so two classic ones are Diplodocus and Brachiosaurus living and they lived alongside together if we look at the bones in their neck we see that sauropods like Diplodocus have this split neural spine of the split I'll spawn here it's often referred to be bifurcated neural spine and sauropods like Brachiosaurus have an unsplit rounded neuronal spine and yet regardless of the spine morphology you always see Brachiosaurus and Diplodocus with these s-shaped Verte you know vertical swan-like necks well what are these sauropods doing with their neck well for time immemorial the answer clearly they're using these vertical necks to feed high up in trees I mean why would they have a long neck otherwise and so of course it didn't take paleontologists very long because we're studying extinct animals so we've looked at modern animals for a lot of analogs so it didn't take paleontologists very long to figure to you guys know that there's a long necked plant eater that's around today and so they said oh of course the giraffe it's a perfect living example of a sauropod and in fact there's even a sauropod today known as giraffatitan so you know the Titanic giraffe but if we look a little bit closer we see that this is only these similarities are only skin-deep so again we look not only at the number of vertebrae that make the neck the size of the body size of the neck of course aspects of their reproduction their digestion parental carrots that are etc we see that the two are in fact very very different and I would say that you know again the comparison between the giraffe and a sauropod really is only skin-deep and I say we need to actually get you know stop making this association between sort of between giraffes just being a modern-day sauropods and so of course that begs to ask well if sauropods and giraffes are not one in the same and sauropods are not using their necks like a giraffe how were they using their necks and this was really challenged and studied and I think what's probably the most important sauropod paper of the modern age and this was work done by Kent Stevens and Mike Parrish and what they did is they looked at computer models of scans of sauropod neck bones and what they did is they were studying what's called range of motion so bone tells us the way that it moves so right my elbow can only move this way if my elbow could move the other I have a serious problem right so bone dictates how it moves past one another so what they did is in the computer because it's a lot easier to actually manipulate to big sauropod vertebrae and the computer is they looked at how these two bones could move past one another then they added another vertebra and another vertebra in another vertebra and so on and so on and so on until they got the whole neck and they looked at how they could actually move and amazingly they found out that sauropods like Diplodocus that the necks actually could move up and down only a little bit but that they stuck out from the body horizontally and it was great for moving side-to-side so I think you know again this horizontal not vertical neck posture they also did this for sauropods like Brachiosaurus and concluded that while Brachiosaurus had a more vertical neck posture than Diplodocus no sauropods had that you know that swan-shaped you know telephone pole vertical neck posture and so they argued that in the case of Diplodocus this horizontal neck that's weak side to side was really great and perfectly engineered for feeding on low browsing plants and this is just kind of neat I think from a historical perspective just understanding the history of paleontological ideas because this paper came out in 99 it was immediately picked up by Tim Haines and incorporated into walking with dinosaurs later that year and I think this is still probably the further leus case or the shortest case of a scientific discovery being incorporated and then disseminated to the public through the form of mass media such as kind of neat Kahn understands in the history so that's why if you ever wondered why the Diplodocus and walking the dinosaurs have these vertical next because it was right you know and it was a great change and so I will admit I am like I talked to Ken Stevens like once every week I take a bullet for that man I definitely am a disciple of Stevens principles and I was fortunate enough in some of my own research to sort of aspects of it that I think really supported the horizontal neck posture which the horizontal neck posture is the most debated concept in sauropod paleobiology there's what I call you know horizontal knickers and the wrong people and they're that polarized that I mean that's how you get sore popular biologists arguing with each other is talking about the posture of the necks so I got to you know at least I think have my own contribution to set argument and it all really started around a classic sauropod biomechanical model so in 1942 the brilliant Scottish anatomist da Thompson looking out his window at Scotland's Forth Bridge and he realized the body plan of a sauropod is very similar to a bridge right you have the two large you know vertical components of the bridge which are similar to the limbs and girdles and you have these long extended cables no even at the time Thompson back then was thinking of horizontal sauropods so he was ahead of his time for certain but he came up with this classic model called the sauropod suspension bridge and if you look up any dinosaur biomechanics work this is the classic example you'll always see but there are some problems again when people subsequently looking at Thompson tried to relay these soft tissues over the skeleton because again you know people were looking at crocodilians Birds and giraffes and even though because of comparative vertebrate anatomy so all these animals with bones right we mostly have the same bones we have the same soft parts going on but what we do with them is a little bit different and so the same is that the anatomy of a crocodile Yin a bird and a giraffe are all very different and people have been trying to reconstruct the soft tissues of sauropods using each one of these as a model and of course they weren't coming to any consensus there was always argument disagreement and this was no different with the neck so when people were trying to reconstruct the anatomy of the neck and where I come into it the anatomy surrounding the bifurcated neural spines so the split neural spines people are trying to argue was there muscle in between those two spines was there air sacs what was going on and so to try to solve that people were just looking at animals with long necks but as we've learned all long necks are not created equal so I went back to the drawing board and while a sauropod neck is indeed a long neck it also represents a heavy mass place off of the shoulders so I decided to look at a living animal today to try to understand what the soft tissue was to find an animal that had the greatest head to body ratio that was alive today and I found that in something that did not have any long neck at all I found it in a very unusual breed of African Cal that is near and dear to my heart now called the and Coley Watusi the N Coley Watusi is the largest horned animal on the planet so this is lurch I got to work with lurch before he died lurch broke his own world record several times in his life I can at least say this that you know madness to ceratopsians they had nothing in comparison to horns of Watusi no questions asked lurch was a particularly amazing animal we used to put pants on his horns to show the size like you know Jarrod it's uh boys like how much you'd lost but also used to put a saddle on lurch and kids would ride him around I was just really cool he was a big gentleman for the body of an animal that's actually not that ridiculously big so I found the what to see we did not have Watusi skeleton so I literally put all my chips on the table and did this as a gamble and I had three what to see cows delivered to to Bozeman Montana where I was doing my masters at the time and we wanted to see going through all of this having these three exotic African Cal's delivered if they had bifurcated neural spines no one knew so we did large-scale dissections and of course I was very happy to report thankfully that the Watusi does have bifurcated neural spines now admittedly it's not the same that we would see in a sauropod but this was actually the first documentation of bifurcated neural spines in a quadrupedal herbivore around today so that was neat now again I want to document the soft tissue because what's going on with their split spines what soft tissues are associated with it well the what you see is a cow so its muscles and everything were pretty much the exact same proportion and everything as a count but what was really special and unique was what I've highlighted in green here which is called the nuchal ligament the nuchal ligament runs him from back of the head all the way down the hips they call it a different name once it gets in the back but for simplicity sake nuchal ligament but what was different about the Watusi was that we're in top views we see where the neural spines split so did the nuchal ligament into a left and right half and so if we look at other animals today in their new Cole's why do the Watusi have this split and branched ligament that was unlike what we'd expect in other animals well I propose it had to do with this that large head now it's not simply about being able to support that weight bison have a big head right and they actually shorten the length of their neck and then they get that big shoulder hump right so that's one way you can go back here and wait but for the Watusi it's not just that the horns are large wait it's a large weight that they have to keep mobile off of their shoulders and move around and so I started looking at other tetrapods both extinct and extent and I actually found that bifurcated neural spines are incredibly common and distributed throughout tetrapods everyone in this room you have bifurcated neural spines in your cervical so in your neck because guess what we have a large mobile weight we have to keep off of our shoulders and in fact we don't realize but our part of our ear anatomy is basically like a bubble level and we don't realize but we're actually always moving our head to keep it level so we have to have a large mobile weight up front off of our shoulders there are some animals like stegasaurus that also do it in their tails but again it's a large mobile weight that's positioned off of the body so that was really neat and so I took the muscle proportions of the Watusi reconstructed them onto a sauropod and also reconstructed this split ligaments but during this whole project there was something that was deeply troubling me and that was Thompson's sauropod suspension bridge model and the big reason that this was troubling me and it been so popular for time immemorial but the big issue is a bridge is meant for static forces right a bridge is meant to be stable and things move over it generally speaking if you have a moving bridge there is a problem so I kept that the sauropod suspension bridge while superficially there were elements of it that certainly I think are suitable and analogous it's not a really good model for the sauropod bowel plan and I kept thinking about this and it kept troubling me and I was driving along with my ex-wife one day to go visit her grandparents and I'm thinking about this and we were driving in Montana and I happened to look off in a field and I see a thing out in this field that I've seen a thousand times before in a field but I realized there in the moment that was my Newton's apple that here I was looking at something that was a what I thought was a perfect mechanical analog to a sauropod I was so captivated with it that I in fact drove off the road much to my ex-wife's dismay and she couldn't understand why I was jumping on the car and taking pictures of a central pivot irrigator so those of you who may not be familiar with central pivot irrigate errs you know they're very popular irrigation system here in the West if you've ever been flying and you wonder what all those circles are it's because of these pivot irrigator x' and a lot of peer of it pivot irrigate errs the way they're designed is they have this long horizontally extended piece that's the sprayer and then they have these v-shaped brackets that run along the top and a left and right cable that's suspended between these v-shaped brackets and they are in fact when the central pivot irrigator was actually introduced in the world in the 1976 issue of science magazine it was hailed and purposely designed that way for dealing with stresses as it moves left and right in a field so I argued that the central pivot irrigator is a much more better mechanical analog to certain sauropods but the whole key to this what I think is a sort of the linchpin the success story of this is that split ligament now a lot of animals take advantage of ligaments today right the ligaments are alast and right there basically nature's rubber band so a lot of animals like kangaroos right they spend a little bit of muscle energy to start the bounce and then it's free energy sort of like a spring stored up in that ligament racehorses do it as well and so sort of analogous to you know the drinking bird on it tipped on its side is that's how I proposed was the sustained mechanism to the lateral sweet feeding of stevens and parish was that people had always wondered with this like well how could they sustain moving their neck side-to-side for so long so in this case the sauropod spends a little bit of muscle energy moving its neck one way or another and then it can just using that elastic energy sweeping side to side to feed and again these things are probably feeding you know fifteen eighteen hours a day so they need a more sufficient way to sustain it so this Apatosaurus could sweeping clear one area of vegetation take one step forward and it's in an entirely new swath of vegetation which is way more energy efficient because think about it if you're feeding from a tree what do you always have to do you always have to walk around your tree right the tree doesn't move or in relation to you so again the fact that this horizontal sweet feeding is way more energy efficient so a way to sustain feeding in these Titantic animals so that's next the second part we'll talk at that's near and dear is I like their sauropod life history so how they grew up so even though sauropods are the largest animals that have ever lived on earth they actually do not come from our largest eggs so the best sauropod nesting colony that we know of in the world to date is a place in South America called a coma wave oh and the eggs there are about the size of a cantaloupe and we have embryos and eggs which that's really helpful because a lot of times we have dinosaur eggs from all over the world but unless we have embryos in them it's much harder to say yes this egg came from this kind of dinosaur there are other nesting colonies in South America and there's another one and elsewhere around the world like one in the Pyrenees but we don't have embryos in there so it's harder to say if those were sauropods and we do have some baby sauropods baby sauropods were not bipedal don't trust that top left image that's just hey leo art they were quadrupedal their whole life or at least but half of them or at least half of the year for a period but we do have do have young baby sauropods and there's a lot we can glean about their life history because again think about it this animal hatches from an egg the size of a cantaloupe to become the one of the largest animals that's ever walk the earth how long did that take though that was part of my master's thesis are really the bulk of my master's thesis was trying to understand the life history of these Diplodocus sauropods and so the most famous Diplodocus sauropod is Diplodocus so that's what I had the most samples of and of course I wanted to understand how long did it take to grow up and this is a easier said than done now paleontologists used to think that dinosaurs were just really big reptiles and if reptiles take a really long time to grow a really really big reptile must take a really really long time to grow up so people were coming up with these estimates saying sauropods you know it took centuries to grow up and this was respectfully not based on anything it was just hogwash the way we do it which I'm sure people are many speakers here you know end of the lecture have probably noticed um of course great research that the Terrell does a lot of is to determine the age of an animal we do what's called histology so we actually take aim we break the bone open and we look at the inside now a lot of people refer to this as you know destructive or they think it's damaging but I will say you can learn more about the inside of an animal than you ever can you can learn more about an animal by looking at the inside of its bones than you ever could by looking at the outside so I think since its enhancing our knowledge I refer to it as enhanced sampling and fossils aren't these rare you know pieces of art you know they're they're scientific data points so let's actually use data to learn something so I cut open everything I can I'm even doing the first histology on sauropod skulls right you know so let's let's learn with the data that we have so I did that I actually cut open these sauropod bones and in like manner two counting tree rings they you know you see a tree cut down in you see these annual growth rings you count those rings and you determine how old the tree was we can do a similar thing in certain bones of dinosaurs sauropods are a little weird we have to do it in their ribs which is very odd not their limb bones because they we're growing so fast that that birth record gets obliterated in their limb bones and so what I saw was that in some of our smaller specimens we saw a minimum of two growth lines which we were then able to indicate that in this six meter long Diplodocus it was about two years old an 18 meter long Diplodocus we see eight of these growth lines a lot of them were starting to be we call it remodeled we were losing parts of that growth record so when we basically calculated missing lines we determined that that animal was an 18 meter Diplodocus was probably that's low you know early teenage years and in our biggest oldest applauded kiss specimens that I was able to sample I was so a 24 give me a 27 meter long animal I was able to count 24 growth lines so we determined that this animal is approximately 30 years old when it done so again think about that 30 years to go from a cantaloupe to a hundred feet long for argument's sake I you know the dinosaurs this isn't in something new we know that the dinosaur record that they grew incredibly fast um some duckbill dinosaurs had faster growth rates and sauropods but again imagine this you know I only partially joke where I bet with times you can watch a sauropod grow right they were growing up that fast especially earlier in their life history but there's a lot more than we can learn from just how long did it take these animals to grow up so in these drawings here these scales we're looking at animals that are the way the drawings are related what we'd call isometric so that just the way these drawings are depicted it would shows that you know a baby sauropod is just a scaled-down version of an adult and a lot of peeling oncologists used to think that was sauropods but it is adamantly vehemently 100% opposite so again something that's a lot of forefront and paleo research is called fancy terms for our radical onto genetic trajectories so the poster child for this Triceratops right how the horns and the frills change dramatic shape as it grows up and we see the exact same things in sauropods and I would argue the animals that we see the greatest size change through their life history are the animals we should expect to see the greatest rat ontogenetic trajectories in now sauropods big spoiler didn't have horns and frills so what the heck was changing in their skeleton geing when they were growing well it's the rest of their skeleton right to deal with being so big so I was able to document that through growth those bifurcated neural spines in adults are not present in the really young immature animals they have a single rounded neural spine and it actually grows through ontogeny now this is really neat because this has implications for feeding right this is suggesting that young Diplodocus are moving their neck differently than older animals and if they're moving their neck differently that probably has something to say that they were feeding differently through growth but of course you know we can talk about necks food but if we're talking about food they're sort of one end of an animal that we have to talk about of course that's the head right the business head and a lot of paleontologists even a lot of sauropod paleo biologists think that sauropod skulls are the rarest of rare fossils and they almost talk about them and you know hush you know hushed whispers and this is where I get cocky I think sauropod skulls are you're gonna find fewer sauropod skulls and ephemeral lying around the museum collections but I don't think they're as incredibly rare as people talk about and in all fairness I've never had a problem finding sauropod skulls I find a lot of them and I even got to work on one really incredible skull so this just for reference because I always like it as a size scale so this is a cast of an adult Diplodocus longus so again you look at that the body of this animal is about a hundred feet long but the head is basically the size of a horse right so just remember that mental picture of how big it is in my hands anyone see a baby this is Andrew so that's Andrew in my hands the skull is nine is that nine inches long in fact Andrews the smallest Diplodocus skull that we've ever found to date and so you can see like your the teeth here's the eye Andrews an amazing specimen I was really honored and fortunate to work on it and perhaps there's a lot that we learned through Andrew about the development of the skull of Diplodocus through growth but perhaps I think the most interesting thing that we learned were it's about its teeth so sauropod teeth basically come in two flavors so they're teeth like Diplodocus which are these peg like teeth and you have Cameron swords which you can see again a great cast of in the gallery they have these really spatulate teeth now Andrews a Diplodocus it should have just peg like Diplodocus teeth and it does have those in the front of its mouth but in the back of its mouth Andrew had camera soros spatulate teeth which is really fascinating and never before had the two tooth forms ever been documented in a sauropod now we know for a long time that teeth correlate to what an animal's feeding on right like the pointy teeth of a Tyrannosaur indicate it was feeding on meat right we know that a lot of similar things for sauropod teeth so there's been a lot of work over the decades that shown that the peg like teeth of Diplodocus which are more grass IEL delicate are used for softer plant types such as ferns where the more robust spatulate teeth of camera source are for coarser vegetation such as cycads and Andrew with the two tooth forms indicates that it was feeding on a variety of plant types which of course makes sense right instead of be you know being so specialized in a certain kind of plant early in its ontogeny baby sauropods like Andrew could just have free access to the salad bar right will eat whatever they want and then now I guess you like a Swiss Army knife the different tooth forms mean that these young sauropods could just have it at the right tools for the job for all of the plant types they could bulk feed everything to grow so incredibly fast but we were able to learn more about Andrew than from Andrew than just the head so here Andrew shown in blue the red specimen is the second smallest opatija skull to heaven known and gray as an adult now these body sizes are scaled it's head size the body length but again this assumes isometry right so the same you know proportions through growth which we know again in the whole dinosaur record is clearly wrong and I wanted to come up with a better picture of what these young sauropods look like with the rest of their skeleton looks like now Andrew we only had a skull but Andrew comes from a bone bed of 15 other individuals so I looked at all of the other skeletons that we had looked at the range of size variation shape etc and I came up with this this was a skeletal reconstruction that I made and I showed this to a bunch of other sauropod colleagues and unanimous across the board they all said it you know the same answers that can't be right there's absolutely no way that's right look at those gangly legs those proportions how do you know that's right what is your supportive evidence and I very clearly say and believe my evidence are is animals today as a lot of baby animals are really stupid-looking right they have these incredibly long gangly legs and this is a hallmark of rapid ontogeny that we see in mammals it's not only an indication of rapid ontogeny we see these long leg proportions in animals that often don't have the same degree of parental care or they have to be highly mobile once they're on their own and we think sauropods were basically analogous to sea turtles parent you know mom digs a nest lays the egg leaves them on their own so the young are raised and lived in their own sort of set age Thakker gated hurts so they had to be on the move fast right we see this again today right puppies really big paws they grow into their paws right and so I think that a lot of these young sauropods had these really gangly legs because they were basically growing into their legs throughout their life history so we took all of our science this was really cool I never actually got to work with a paleo illustrator before so I was really honored with that and so we took our science and we worked with the insanely talented paleo artist Andre tattooin and Andre took all of our science and made a visual representation of that so here we see young you know gangly Andrew feeding on a different plant type than either one of it to the two adults so that was a really fun project and there's lots or that we not only deciphered about diplodocus growth and life history but there's still a lot more work coming up so one of the things we're doing is because I have now a wealth of Diplodocus skulls is from an oncogenic series is some of the things we're looking at for instance are CT scanning the brain and actually looking at how the brain changes for ontogeny lots of really cool work to come so I hope you've just been able to learn a little bit more and maybe you appreciate sauropods a bit more you know they are unfortunately quite often treated as being the dumb very vanilla dinosaurs in it other than their size there's nothing special about them but I hope you've been able to just from two very brief examples today see and understand that they actually are incredibly not only interesting and amazing animals but again a lot of the biomechanics the bioengineering that's gone into their life history and their evolution to be able to get to be so big it's a lot of things that we don't see in fact in any other dinosaurs and so we really I think probably biased opinion should be doing a lot more research on sauropods because if we're trying to understand for instance why do dinosaurs get to be so big maybe it's not a bad idea to look at the biggest of the dinosaurs right to try to answer that question or even how to get big so fast so with that I want to thank the course the Royal Tyrrell Museum here in the speaker series that even brought me it was able to bring me here to have a wonderful time I've had a great week so far looking in collections I'll have today and part of tomorrow to do that as well of course at Patty Robert and Francois for just notifying me about this program bringing me here of course all of you in attendance today so thank you very much you

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Id: GyWu4MZeaGs

Length: 39min 29sec (2369 seconds)

Published: Fri Feb 21 2020