Could we ever know how dinosaurs thought or behaved?

right good afternoon ladies and gentlemen my name is Malcolm Brown I'm president to the Geological Society and welcome to this the fifth Society London lecture of 2018 which has been designated year of resources today's lecture is entitled could we ever have known how dinosaurs thought or behaved it's my pleasure to introduce our speaker dr. David Norman of Cambridge University the last naive UN dinosaur trot the earth about 66 million years ago so researching such ephemeral topics as thought and behavior in socials long dead creatures presents us with many scientific imponderables he's arguably one of the ultimate forensic challenges David is a paleo biologist based the Department of Earth Sciences in Cambridge he trained at Leeds University and then King's College London and the Natural History Museum where he worked on Iguanodon he worked in Brussels on these extraordinary big wanna dawn disturb discovered it Ben Issa and later returned to London at Queen Mary's College within Oxford University before working for the government he then became the first director of the sedgwick museum post he has held for some 20 years dave has been involved in paleo biological research and all continents except Antarctica has trained some the leading vertebrate paleontologists of the present day and has written several books and dinosaurs and their biology including recently dinosaurs a very short introduction with Oxford University Press ladies and gentlemen please welcome David Norman [Applause] thank you very much Malcolm good evening and here we go we're talking about dinosaurs and trying to really investigate almost from a forensic perspective how we might induce or did use aspects of their biology behavior and so on and to do so you need to draw in various aspects of the things that we know that are associated with dinosaurs that could be hard parts it can be things left behind by dinosaurs and the the tasks we're faced with is that given that despite Jurassic Park and what you might read in the media these are extremely rare things actually drawing the information together and telling a coherent and in a sense believable story is the problem that we all face it's when in any historical science it's that sort of problem it's trying to draw together something where you don't have a time machine to go back and test in a verifiable scientific sense in a pop Irian sort of world exactly what your deductions have been or what you've induced in terms of the data that you've seen so it's an impossible task so my skills if they are any are ones where I'm trying to be persuasive it's the skills of a barrister I'm trying to persuade the twelve honest and true citizens that my interpretation of the circumstances is the most plausible therefore you find the the opponent guilty but that aside I want to try and draw you through a process of how we make reasoned deductions or inductions about the information that we've got and draw together I hope a series of strands that sort of in a sense tell a pick tell story and build a picture of what dinosaurs were like you know in a in a reasonable way and embellish it a little bit by thinking about this issue which I've sort of tempted you with which is you know how have you know how they thought I the contents are tangential to that but nevertheless maybe maybe we can develop some sort of insight into the subject before I actually start the lecture I just like to say in a way this is a sort of thank you and memorial to some body who you may know or some of you may know Martin brazier professor at Oxford tragically killed in a car accident just before a meeting a few years ago Martin and I had since we were both at Oxford to be cross swords over a particular specimen and argued furiously for about three years to basically to no avail but I got the result out in the end so sorry Martin will hear about that a bit later so let's get on with the lecture so the strands that I'm going to try and in a way and they're not as clear-cut as they seem in those four points there but I'm going to try and sort of structure the lecture a little bit despite the overlaps to to show you how the information tends to get put together so we'll deal with footprints elements of anatomy biomechanics although they sort of overlap both ecology and soft tissues so we it's sort of getting closer and closer to the soft soft part of the biology of these creatures and the geological circumstances that might have led to some rather interesting preservation so let's get started and deal with number one footprints trackways the the photograph on the Left top left is a specimen from Yorkshire it's a Jurassic footprint and you can see those three nice long Lawson u-shaped tobert toe impressions of what well it's Mesozoic and if you look at the the technical drawing here you can see these rather long loss in shape toes and it seems quite probable that what you've got here is the impression of a footprint left behind by creature like this which was quite large predatory dinosaur the foot corresponds to the print and in truth if you were to touch that specimen you're as near as you're ever going to get to a dinosaur a dinosaur went past that left that behind it you're terribly close to the actual critter that left that it's one of those rare quite common things but it's in a way when you think about it's quite moving risking a joke that you might have you might be that clips to the critter that actually left that that as an individual specimen is interesting per se is pretty it tells you something about the animal and perhaps the nature of that animal I know because of the shape of the toes that that was a carnivorous beasts its feet are rather distinctive so so I can begin to induce from the data are some sort of scenario as to what this critter was so that that's something moving in a direction of a live animal on other occasions if if you're lucky sometimes you can find arrays like this this is a footprint trackway lots and lots of as you can see superimposed footprints which were not the same shape as the footprints that you see over there they clearly they're not elongated toe impressions you have rather large rounded plate like feet which poses a question again they're Mesozoic they're big you know some of these footprints are about yea big so these are really quite large feet but what left them and that's where having some understanding or knowledge of the overall anatomy of various creatures and they are varied so you need a sort of it's like encyclopedic knowledge of the different varieties of anatomy to help the interpretation ends up with the most reasonable interpretation of the shape of those four which are basically more or less plate like circular and then some others that are D shaped that are often associated with the big plate like ones and the animals that have the right configuration of toes are these these are so-called Brachiosaurus they're obviously rather large elephantine creatures they can be up to 25 meters in length may have weighed somewhere between 15 and 20 tonnes it's a big animal big feet big impressions and you can see the similarity of general footprints or it's a bit characterized but you can see that the feet are rather distinctive and similar to the footprints that you saw earlier so we know roughly what type of animal left the footprints but there's another message there's a whole bunch of them moving in that general direction in the same group we have what appear to be a set of overlapping footprints you know things are one footprint is left behind then another steps on top of it so you seem to have a cluster of these animals moving together in the same direction at the same time which is a rarity you don't often have an opportunity to get that close to the timing of footprints being left and in this instance there's also another story that emerges which is that there are big footprints out here and smaller ones here you could argue quite plausibly that you've got a structured heard or darris a flock of dinosaurs moving in the same general direction and perhaps you might be able to reasonably conclude that there actually is a structure to the herd Biggins on the outside small and more vulnerable specimens in the middle so that's interesting in terms of a behavioral repertoire that these dumb stupid animals may have had which is sort of runs counter to that old ancient sort of Victorian view of what dinosaurs were old slow stupid things destined for extinction and and I'll keep repeating that sort of contradiction you know the old perspective versus perhaps a reasonable forensic understanding of what these things imply about the biology and way of life of these animals so already something as big and stupid as these huge dinosaurs may have had a rather structured life some sort of implication of social interactions and knowing how to move especially if there's some big meat-eating predators around which when you want to protect your young isn't that something similar to animals that live today yeah in a general sense there are other messages that come through which relate to the shape of the foot big round plate like feet there are other animals that have big round plate like feet are they big and heavy as well elephants there's the sole of an elephant they don't have individual toes sticking out they have rounded print footprints and would leave footprints rather like the ones that we saw why because they're energetically efficient if you weigh 15 tons and you step every time you take a step although we don't tend to appreciate it you lift your center of mass one of the neat things about dinosaurs is that they actually walk on the dollar toe tips of their toes they all do that if you walk on the tips of your toes as all the women might be familiar with if you wear moderately high heels then you raise your center of mass and you sort of glide along the surface your head doesn't Bob up and down Olympic runners no the same Usain Bolt when he's running at speed he's up on the tips of his toes watch his head it's absolutely flat he's not wasting energy moving his center of mass up and down elephants do the same if you weigh four or five the last thing you want to do is waste energy lifting your body and then dropping it again so up on your toes and neat have an elasticated ball of tissue behind the foot which stores elastic strain energy when the weight is on the foot as you can see it compressing and then releases it as the weight is taken off for the next so you get a Spring Heeled effect dinosaurs did the same elementary biomechanics in relation to a large heavy in this case herbivorous animal it makes perfect logical sense and why shouldn't they they have the efficiency of locomotion seen in modern animals like elephants perfectly reasonable some of you may have attended Emily ray fields lectures you want from one of my former PhD students wish you looking at the biomechanics of dinosaur skulls its again it's the taking the energy engineering principles hate that's not geology and applying them in an interdisciplinary way to a problem and try to solve it that way by using a range of different scientific disciplines this is forensic science at its most basic bringing in different scientific disciplines to try and solve a problem provide you to realize as a problem so back to the structured herd maybe this scenario in this lovely picture by John Gertz isn't isn't completely fake you have these very large critters on the outside little youngsters actually rather large animals but nevertheless little youngsters compared to the adults being protected by the outriders against lurking predators it's not so unreasonable in relation to those footprints that we saw just as a while ago and we've we've built a a reasonable scenario about a biology in a way of life and that has implications about the the the mental thought processes that the dinosaurs were going through to actually do that to have in a sense the wisdom to realize if you move in a structured hood if you're young a safer not unreasonable a third more relatively recent discovery it was friend of mine martin luckily he was based in denver colorado has done a lot of work on fossil footprints and more recently he's discovered that there appear to be these cleared areas and it's not just a one-off a number of different sites have been found in colorado which appear to be cleared areas within which you find these very characteristic doubles scrapes which pits so double pits with piles of sediment on either side and the you could say the fanciful but the interpretation that was eventually put on this is this is not a weird geological sedimentary phenomenon we actually see scrape marks on the sides of these pits where these things animal snatchy dug these pits out and what he proposed was that this was actually a lek it's rather like grouse capercaillie and things like that they create an arena the males and perform within the arena to attract females maybe what you have here is Tyrannosaur like animals creating these scrapes and these Lexor rhiness within which they behaved again is that sluggish stupid destined for extinction type of behavior in these sorts of dinosaurs it sort of implies things about in a sense the awareness behavior reaction to the environment and again maybe to some extent females are dominating there at least the sexual selection going on here the most elaborate displays the most flamboyant males are being selected in a reproductive sense by the females bit of power for the females there so and other artifacts like tracks can actually imply quite a lot about the behavior and way of life of these animals that that perhaps create a more richly textured view not it's not the dinosaurs it's what they've left behind what they have left behind occasionally is quite reasonable skeletons sometimes they're patch works that have to be put together this is a thing called Deinonychus a great friend of mine called John Ostrom who sadly passed away described this he was based in Yale found this in Montana pretty much complete and the question then is what style of animal is this and and your common sense when you simply look at the body proportions the proportions of the limbs the there are the wonderful balance of the animal it's running on its back legs only its front legs were grasping it couldn't use all fours it had to have the neural integration and the wops called technically proprioceptive feedback from the muscles to the rest of the brain to say hey we need to be able to balance here so we need fast feedback between the body and the brain to result in the reaction to the muscles to maintain the balance think of a toddler and the amount of time it takes him to learn how to hurt to learn how to walk on two legs these guys were doing it it it implies a degree of neural sophistication within the brain so allow that posture less alone the the implication is actually think could scamper around pretty fast it's also got eyes that point forward all the better to see you with it's it's really a rather sophisticated animal dull stupid destined for extinction possibly not it's an extreme example I know it's an animals on the line leading to birds so again the the bird connection also you know implies a degree of sophistication that some dinosaur if we take it a little bit we start to probe this isn't the same animal obviously but the ant the same the same things apply to the thing that we just looked at as this animal here this animal is appropriately named air austin this bones are full of air basically this is thus as much of the skeleton own every bone so this bone has been sectioned this large hip bone has been sectioned across here if you look at the interior it's full of holes air-filled cavities even the clavicle the collarbones here have cavities in them there are pneumatic opening these vertebrae are just amazing structures absolutely riddled with holes many of these dinosaurs are incredibly light they look gigantic but it's rather like an ostrich you say Oh big bird that's gonna be really heavy you can sort of pick it up with one hand they're incredibly light these animals were big but light most of them the reasons I said most of them is that they're not all the same dinosaurs are many and varied so when we're looking again this is the complexity when we're looking at overall general scenarios of explanation we have to also be able to be aware of the diversity the this isn't on if this skin it doesn't have air filled bones so okay so it's a dinosaur it's different the parameters that affect its biomechanics and its operations a critter in general terms are going to be different from those that apply to the air to animals we've just seen so some have wait wait saving adaptation some don't some move fast some don't this is a bit of a plodder that's a rather slow moving creature judged by its overall and a semi and it's a lot heavier than than the light air-filled things that you just saw so we have to be careful because though is it's such an easy thing to just take one group as our but they're all like that when in fact they're not so the breadth of understanding is something can cause compromises in terms of getting a general understanding so anatomy and biomechanics and have a work sort of underpin and understanding of how the animal works and that has implications for its neural circuitry the things that control its body movement some if you think about bipedal forms need of rather sophisticated fast brain with very fast interactions between muscles and nerves that need to be coordinated by a thing up here to allow for bipedal running and balance others don't so maybe there's a diversity of brain types another way of looking at them is again to take real Anatomy and this this is I'm sorry it's not as clear as I'd like it to be what you've got is a series of thin sections through bone of dinosaurs and the point and I'll just try make briefly is that the cross-sections reveal the internal structure of bone when dinosaur bones are found they haven't gone through a process of mineral replacement there's a sort of general perception that you pick up a dinosaur bone and and basically it's been in filled by minerals and that's it our bones are made of calcium phosphate the mineral apatite fundamentally it's an extremely durable mineral so any dinosaur bone that you pick up is full of the original mineral it's the original dinosaur bone what's been added through permineralization is all the interest and all the space has been filled up with extraneous minerals that were brought in in the ground water which makes bones heavy if they haven't gone through that process and there's some lovely material that's I've seen in it's small baby Tyrannosaurus Rex in in Montana that was fortunately it died and got rolled into a mud ball so there's no water percolating and when you dig out the bones they're light as a feather they just like the bones of recently dead animals depends on the circumstances obviously in this instance when you take thin sections through the bone you can see that there's a fabric with holes in it fundamentally you've got blood vessels forming a mesh which are bringing the minerals in which are allowing the cells to grow add bone to the surface of bone to build up the boat and fabric and the strength of the bone in dinosaurs this one in the middle you can get a slightly better impression you can see there are what appear to be these white holes that's the blood vessels but they seem to be layered you have the in effect climbed what you've got is these incredibly rapidly deposited layers of bone to create this plywood like structure now the only animals that can build that sort of bone are animals like young birds that grow incredibly quickly so dinosaurs could also and actually need it to grow very quickly and would have needed the physiology to allow that growth to take place very rapidly so there are implications in just the structure of the bone and how it grew and how quickly it grew that reflect back on the metabolic race of the animal they also restructure their bone and this is what happens after you've grown your bone in plywood form very quickly in a sense you have to sort of stop paint the hang on I'm gonna walk around that imposes stresses on the bone and to compensate for the increasing stresses as growth increases bone needs to be remodeled in an engineering sense and what you've got here is what is called secondary or remodel or haversian bone which is that stuff but it's been burrowed out you've had got cells that have gone through the fabric of the bone destroying it and behind it so ourselves that build new little cylindrical structures that are elongate had organized along the lines of stress within the bone so you can see that this is actively growing because these these sort of thread-like structures are growing through the bone but they keep adding them so what you've got here is a lovely example of an Austrian or Persian system there that's actually etched away that one there so she sort of burrowed through an osteon so this is actively remodeling and re remodeling as it goes and your bones do just the same do you think of your bones as being solid permanent they're not they're dynamically in equilibrium with your body all the time if I return to go sort of an exercise regime and start stretching my shoulders I would deposit extra bone to accommodate the extra stresses around my shoulder it's part your bones are doing the same all the time it's a constant turnover of minerals it's again we're getting closer to the biology of the animals indirectly by looking at structures that seem a bit abstruse but actually relate to an understanding of the overall biology a fourth line is soft tissues this is where maybe things get even more interesting possibly we we all know very well mats in the 1990s a variety of Chinese specimens usually from loaning in northeast China we're discovered which had curious well they have nice skeletons well frustrating skeletons they crushed flat so it's really difficult to work on the bones but around them is a halo of brown stuff this is actually epidermal tissue and things growing out of the surface of the skin in either in the form of hair or filament like structures or actual feathers and when you get a microscope you can actually see some of these fabrics that are growing in the surface of the skin and out of the surface of the skin the example here is a much more recent animal from Siberia a friend called Pascal discovered this and described it it's very interesting because you can see here it's got a scaly tail as all reptile should have its body is covered with this sort of hair like filaments and it's legs and arms have feathers it's got this diversity of skin covering which breaks up the model you know as a modern biologist you know that birds have feathers and that's what defines a bird no no longer there are a whole range of dinosaurs that and this is nothing to do with birds this is an all of this skin it's nothing to do with bird origins oh that's another story because I've messed up the family tree of dinosaurs recently but nevermind the point is that if you've got structures like that in animals this could not fly it just hasn't got wings at it there's you know forget birds why has it got this stuff well if it's if it's a conventional reptile then it would need to bask in the Sun to keep its body warm the last thing you want if your reptile is an insulated covering it can't reflect the heat rather than allowing you to absorb it to maintain your body temperature these things must have been able to generate body heat internally and use the installation to stop losing body heat out to the environment that means they generated heat internally that tells you something about their metabolic rate and the greater similarity to mammals and birds today perfectly reasonable and we haven't done anything like rocket science it's just a logical set of interpretations based on what we see and what we know of animals living today know nothing clever about it's just the logical inference so the scenario of feathers is they weren't invented flight they were invented for installation of course they have fossil records telling us that so where did this come from well there's a whole range of dinosaurs that have various forms of plumage some ridiculous like this great fan geisha fan on the end of its tail rather sort of inadequate wing feathers the again an overall interpretation would be that installation was invented dinosaurs would have mated sexual selection would rear its ugly head in a sense males may perform to try and attract mates so if you've got a Geisha fan you've got sort of colorful plumage then maybe you can attract a female and reproduce and pass your attributes on to the next generation if you could then augment that by jumping up in a branch and fluttering down make your display even more fantastic maybe that would give you a selective advantage maybe that's the origin of flight feathers way down the line from the original installation that developed in these small highly active animals no ok flights of fantasy sorry again didn't mean that pun but um these sort of these slightly fight flight of fantasies sort of interpretations are built on a set of observations and reasonable inductions I don't think I'm saying anything that's that's wildly controversial in terms of the biological import but it has implications on how these animals worked behaved and what their physiology and metabolism was like it's sort of an inevitable consequence of picking these bits these little bits of observation drawing them together into an integrated scenario so can we take this a little bit further yeah of course we can I'm going to try and fill up an hour I'm going to use two examples there's a sort of sort of technical drawings-- slightly artistic but technical drawings of dinosaurs that we know some of them have great big sort of broad snouts they called duck-billed dinosaurs for a reason they have rather broad duck like bills some of them have odd excrescences prongs and things on the top of their heads and this one's got a sort of pipe like thing here and this one's got a helmet my crest I'm gonna use these two examples just briefly - to investigate what that might mean and how it might be interpreted so this is Parasaurolophus which is that fella over there with a pipe on his head and colourful restoration we don't know what the colours were like in general terms but nevertheless that's the overall impression of the critter with its duck like beak and this in enormous pipe on the top of its head which went from the nostrils backwards and in the past people have tried to say what what were these for quite reasonably and these are the various theories was a snorkel so these dabbled in in aquatic vegetation and on the waterline and while the head was underwater they could breathe through the snow so great perfectly reasonable except that's closed off so snow doesn't work another one well maybe it was a reservoir for like scuba diving if you sort of taking the story in this is in this container and breathe it when you fancy it the volumes just don't work it's just ridiculous so and these are published in the scientific literature so we can laugh now but I mean these were serious ideas at the time bronze deflector this is a rare one my PhD super my dissertation undergraduate supervisor at Leeds was musing over this and he reckoned that if they hunch down that had this sort of long tube which they could connect to the back of the shoulder then actually they could run through dense foliage Nick deflect all the branches over them over the back of the animal yeah nobody has disputed that I think it deserves to be disputed but nobody has then we get more reasonable fabulous sense of smell well the breath the part of the brain associated with the sense of smell is right at the front of the brain case and this tube-like structure is very close so if that whole tube was full of sensory cells then maybe it would give them a very acute sense of smell you can't dispute or deny that perfectly reasonable visual recognition it's very distinctive it allowed us to separate it from the other critters that are found in the same rocks at the same age so maybe it was literally that you know it's one of those I want to make with that because I'm one of those or it's used in some sort of territorial display we don't know it seems reasonable and find me honker did it make a noise this is a good friend of mine called Dave wife sample the Johns Hopkins got interested and he's working on these sorts of critters and had this horn or tube CT scanned and look at the complexity of those tubes inside very complex trombone like arrangement and he actually got some plumbing pipes and bits and pieces and put them have a piece on one end and blew down it and lo and behold it sounded like a foghorn and they've also done a computer simulation of the same and come out with the same sound a deep fog horn which makes a terrible lot of sense these animals are known occasionally in relatively large numbers in fossil bone beds they may well have been heard living animals which as prey because they were plant eaters would have been subject to the attentions of Tyrannosaurus they were rough contemporaries Rex for example if you ever heard and luckily one's keeping an eye out and spots a t-rex on the horizon if you made a high-frequency squeak like the tweet of a bird in the present day the t-rex would say it was you straight straight on to you if you produce a deep low-frequency long wavelength sound like the fall corn of a ship you haven't got a clue where it's come from you just know it's there all the whole herd can hear that so can the t-rex whole herds alerted you haven't been identified you get safely away makes a lot of sense in a biological sense but what it what it might be telling us is that actually we've got quite sophisticated communities of organisms that communicate this is not the slow sluggish testing for extinction sort of model it's something different I could take it a tiny bit further because I want to by looking at the other critter so we've looked at that fella and it could have had a multifunctional crest acute sense of smell a visual recognition honking perfectly reasonable you know one structure doesn't have to have one function could have a diversity of functions nature's like that so what about this one well we have modern techniques now for looking at these things the CT scan that you saw just now is now refined so we have aero engineers who will happily loan their CT equipment to CT scan very large specimens like dinosaur skulls because it's fun this is not like an aero engine and this is a surface scan of a beautifully preserved corythosaurus column you can see the crest at the top there this is a CT scan but segmented so you've got the transparent bones here but it's segmented so all the cavities within which we would love to know about are now revealed normally what you'd have to do is accidentally drop the specimen so you can see in the side don't tell the curator but you so I mean that's as a paleontologist you you want to know you want to research but you've got these people who want to keep these things in aspic and can't break them you can't so CT scanning gets you around that so this is the passageway of the nasal tube so the air passes in from the nostril here down a convoluted sort of air passage to the back of the throat and then down to the lungs that passage passes the front part of this move bit here which I want you to register as a shape this is the cavity where the brain was we'd call it euphemistically the brain of the animal front part of the brain just like yours here is where the olfactory lobes are and that feeds your sense of smell so sense of smell is reinforced by this complex arrangement here and the juxtaposition but we've also got this information or there's the brain and these are blood vessels in red and cranial nerves in yellow and that's the pituitary that hangs down from the bottom of the brain Wow quite a lot of complicated soft biology sort of implied in the cavities within the skull itself exciting well sort of exciting so what does it tell you well there's a question is it really the brain and I'm gonna say no relate it's the cavity where the brain sat again human perceptions is that our brain case is full of brain reptiles aren't like that there's a they they have a large brain case and the brain fits inside but there's all sorts of other sinuses and things above so there isn't a direct correlation between the brain cavity and the actual brain so in a sense that makes them look quite smart because the brain looks quite big in fact very smaller than that so he can make mistakes maybe some people could think that's a more intelligent dinosaur than it was so let's look a bit further this brings in some of the research I did years ago the study of the brains of dinosaurs has unbelievably long history it goes back to 1871 John Whittaker Hulk of this society did a lot of work on reptiles from the Mesozoic wheeldin of the Isle of Wight and elsewhere described them amongst which was a block of bone that turned out to be part of the skull of an Iguanodon it wasn't really she ated until 1882 and that takes us back to that the introduction from malcolm where dinosaurs at bonus are in belgium a herd of them were discovered and were described in 1882 and that's when the penny dropped and that ah that bone actually is the shape of the brain case of Iguanodon and so it seems there's Iguanodon it unfortunate rather side doesn't have all these fabulous sort of structures on the root of his skull it's boring but it's the ultimate ancestor of things like the rather elaborate duck-billed dinosaurs so it's ancestral it's sort of little more basic sort of configuration but as you can see it's the same sort of configuration of animal as a plant eater with a bit of the sort of beak a little bit duck like exaggerated but that's just to confirm there's there's one of my boring technical drawings of this beast there's the duct like beak large eye and tucked in here the brain case there is Hulk's specimen it's in the Natural History Museum I studied it as part of my thesis so you do technical drawings those are all the bones as preserved and you can see there are lots of grooves and holes these are actually muscle scars ligaments scars and cranial nerves popping out through the fabric of the braincase there's a sort of technical drawing of the anatomy identifying some of the cranial nerves and the vidiian canal there which is the artery going into the feeble flow of the brain case and you're getting topography and geography sorted out there's the brain case there's the shape of the brain cavity there's the pituitary at the bottom hanging down like a grape you've got this one hump there and then a major hump in the middle and it tapers off to the spinal cord that's the sort of that's the shape I want you just to remember briefly because we'll see it again so I was lucky because whilst I was working on some more material it was a very unpromising block of rock collected from Sussex from a brick pit and somebody thrown it under a bench in the nitrogen museum and nobody knew what it was it was part of the skull of Iguala ville I was able to identify it and got the museum to sort of reluctantly cut it just off the midline and scrape away all the bone so all the bone was destroyed because I could see that actually the cavity where the brain lay and other structures was filled with sediment and sediment very hard and faithfully reproduced the internal structures and there it is these this is the cut area so it so just skimmed the brain as it happens it's just a guess there's that structure the one hump second hump going back to the spinal cord here these are all twelve cranial nerves preserved there's part of the internal carotid artery going into the pituitary fossa here and perfusing the blood within the brain case and this is part of the venous drainage system we used blood passing back to the neck technical stuff that you don't need to know there's another view of the same thing from the other side and just to sort of gee whiz thing these are fine blood vessels here running through the wall of the brain case part of the venous drainage system that is part of the inner area those semicircular canals that allow me to stand here not fall over it's part of the balancing system that operates within them within our brain cases just as much as it did in these dinosaurs well developed and yeah of course they'd have a sense of balance perfectly expected so you go on and on and this is the that shape within the brain case sort of transparent if I'd and these are my guess of the lobes of the brain not filling the cavity but that's what I think it's the cerebral hemispheres optic lobes and cerebellum and then all the cranial nerves and then just to be fancy dancy this is the arterial supply to the floor of the brain case and this is the venous drainage Wow the embarrassing thing is that we know more about the anatomy of the brain case and venous drainage than we do in some living reptiles today so people on the other side of this the archway here take note and then things change yes again this is where martin brazier came in a specimen was found on the beach at Bexhill a very unpromising pebble about yay big and this is it you now recognize the shape hopefully in profile you got a lump here a bigger lump here and it's tapering off into the spinal cord this is part of the brain part of the floor of the brain case and bits of broken bone but that's not relevant Martin was very interested in bio mineralization preservation of tissues as mineral replicas and that's why we started to argue I'll explain briefly what that meant later what he'd seen was so funny structure up here that intrigued and make what if this soft tissue preserved on the surface and what that tells me something about the brain ultimately Martine thought that was a complete solid mineralized brain that's where I disagreed with him has just mineralised up here but we'll go into that just briefly so we argued for two or three years about this then he got killed in a road accident and we published it in his memory just last year so this is the specimen there is Hulk's original brain case from 1871 cut in half it fits perfectly I'm not saying that they go together they clearly don't Bexhill Isle of Wight they do not fit but they are the same size and the shape correspondence is lovely so another sedimentary cast within it of the internal space and it's sort of telling us something as a natural endo cast about the cavity where the brain sat and it might be telling us maybe a little bit more this is a rather bad photograph of the surface that we were interested in on you'll see better photographs in a minute but basically imagine your bed after you've slept on it and you look at the sheet in the morning it's all rumpled and crinkled that's basically what you're seeing a crinkle sheet these are slightly better and I hope you can see the wrinkling on the surface there you can see more of the wrinkling over here on these scanning electron micrographs and this is a close-up of more of that wrinkled sheet with a tube running a bleakly through the fabric it's AIT's a blood vessel running through this crinkled sheet and this crinkle sheet has the appearance and form of what we know is what we call meninges meninges are tough fibrous layers that surround your brain the main cortex of the brain is soft and sloppy but around it there are these tough ligamentous sheets that form a series of layers that's spend the brain and protect it so underneath the brain case there's these tough membranes and then there's the soft squidgy brain and what we seem to be seeing is a mineralized remnant of that crinkly sheet that's supporting the brain amazing it gets better scanning II am show for far more detail which I won't bore you with but I will show you these diagrams at least because you can see things a bit more clearly there are tubes running through the fabric just underneath the peeled wrinkled bits of sheathing so because the the specimens eroded there are bits where you can see just underneath the wrinkles sheathing and underneath there you can see these incredible tubes some of which are branching and look at this there mentions there's somewhere between 25 and 50 microns in diameter just enough room for a blood cell to get through these are capillaries these are capillaries within the fabric of the brain the cortex the squidgy stuff underneath these meninges and this is the vascular supply to that and rather interestingly is broken tube there these are preserved in Siddha right iron carbonate and you can see this sort of amorphous stuff here this is micro crystalline kala Fang calcium phosphate primarily crystals of calcium phosphate which I think are mimicking the fabric of the cortex of the brain that sort of the soft gray matter of the brain they're not replicating the cells of course that'd be stupid but they are in a sense giving you an essence of the distinction between the fabric of the brain and the capillary network within the fabric astonishing I mean if you'd asked me just a few years ago would we ever find soft tissues of a brain absolutely not I mean it's so squidgy it decays so quickly not a hope of finding anything remotely like that I'm completely contradicted by this amazing discovery we needed to sort of verify what the stuff is so these are just spectrographs EDS spectrographs of the the little brown crystals the Siddha right crystals that we found on the on this fabric surface and the and the collar fain and all the EDS is telling you really is that the background is basically silt mostly silicon but the the crystals of iron carbonate are genuinely crystals that are enriched in iron carbonate and the background collar fain is genuinely calcium and phosphate as we as we hope them and as we thought so it's nice to just get that technical back up to support the way we were interpreting that because that was actually quite important in terms of building a scenario and this is this is where you know you're scratching your head how on earth how on earth could this have been preserved so this was the overall scenario that I built and trying to think about the chemistry of what was going on let alone the biology of what we have seen and again it's forensic I'm bringing chemistry in order to try and interpret what I'm seeing and what you've got basically is a scenario it's no more than that and I hate the word but I mean this is the best we can do we're trying to explain how on earth things could have been preserved the way they have there's the critter it must have died there's its brain we suspect that when it died it collapsed and its head or maybe the rest of its body fell into a stagnant swamp the stagnant swamp is important it's no acidic preservative environment as it sank into the swamp because it's lying on its back the braincase up here actually when you turn it over it becomes a bowl so the brain slops into the bowl in this acidic environment in that acidic environment the tissues are surrounding the brain are gradually dissolved by the acidic environment got a phosphoric acids sequence in these swamp waters that means you mobilize the braincase minerals the apatite you dissolve them and create a rich soup of phosphate you also have where's the iron come from oh dear our bodies are full of iron muscle and blood is full of iron we have a natural resource of iron you can build the iron carbonate from the iron that the body provides as it decays you've got a source of iron a source of phosphate source of carbonate in the water and what we suspect is that the brained overturned collapsed into the brain cavity and was pickled the acidic environment pickles these tissues it hardens them enough to form a template against which the minerals could then precipitate so you end up with a localized area here of iron carbonate rich deposit and cola fame calcium phosphate sort of filling and crystallizing in the area in that very acid anoxic environment anoxic because you've got all this decay all the oxygen is consumed as a part of the product of decay and you end up with this localized whoops localized area of mineral heavy mineralization for a short period of time the rest of the braincase rots away sediment is then swept in and these are bits of leaf and all bits of bone and pylean on top as we find in the actual fossil and the argument I had with Martin didn't bless his cotton sauce was we took some rough CT scans and found all these fragments of plant and bone and bits and pieces in this area here and Martin thought ah these the internal structures of the brain itself and that's the source of a deep argument about some how you interpret this but actually when we got better resolution CT scans sadly after Martin had passed away if they were plant and bits of bone and all sorts of other debris that had washed him on top of the mineralized portion so sorry Marty I was right so this is a slightly fanciful view of if you were to dissect an Iguanodon skull peel back the skin then there's the bone surface of the brain case roof underneath you have a complexity of meninges mineralized tough collagenous sheets that surround the cortex of the brain and and there are other sort of fabric structures that we think we can discern his record villi and so on and blood vessels running through this fabric as well from and within the cortex and just underneath I think we just got a trace of the high vascularity of the cortex itself in preserved in iron carbonate with this sort of mush of calcium phosphate which echoed where the cortex or the cellular debris of the cortex was to be found so how smart was dinosaur-like Iguanodon I've sort of generally done a sort of simplified what's called a settle ization quotient estimation based on the guessing how much of that space was occupied by the brain this caused controversy because when people discovered that the brain was touching the top of the brain case is proof that shorty the whole dinosaur the whole brain camp cavity was filled with brain therefore they're smart because it had a large volume of brain but I think our scenario where the brain flops into the roof of the skull means that actually that's a mistake fundamental mistake so my rationalization is here that's a crocodile that standard crocodile intelligence don't underestimate a crocodile they are very small creatures they learn they have very complex behaviors they look after their young they really are very complicated complex business when they're in the right environment but so crocodiles are there in terms of brain volume relations body volume some dinosaurs have a lesser brain size relative to both brain volume relative to body size not surprising these are some of the biggest dinosaur's other dinosaurs like the non-avian theropods and the bird ancestors of theropods have a larger brain a relation to their body volume so Iguanodon yeah it's reasonably smart in dinosaur terms not brilliant not dumb somewhere in the middle perhaps as you might expect it's sort of meaningless actually because it doesn't tell you anything about behavior doesn't tell you about relative intelligence it just it's just a notion of how we might think that the size of the brain might affect will have some bearing on the intelligence of the animals which is a silly assumption ready so smart on the crocodile maybe like I say don't underestimate crocodile but not nearly a smart food line dinosaurs judged by brain volume so where we got you can we ever know how dinosaurs thought in any genuine deke objective way well we can deduce a number of aspects from the functional biology behavior and interpret behavior of dinosaurs through various lines of rent that forensic sort of bringing as much information in as building a sort of general scenario we can even sort of begin to interpret aspects of their Physiol metabolism and so on the exceptional preservation conditions allow us to actually investigate part of the brain structure fabulous but we're no closer to knowing what they thought or how they thought so I'm sorry to have brought you here under false pretenses thank you very much very good thank you Davis questions you've shown us a wide range of dinosaurs and allied genre and and given that the dinosaurs diversified quite considerably throughout the Jurassic and Cretaceous especially around the period of grey seals indeed mammals diversify considerably from the ear seen on words especially primates around the time of the quaternary glacials what do you think the chances might have been if if an asteroid hadn't wiped them out 66 million years ago that some of them might have gone on to develop intelligence not too far apart from the level of our own this echoes some a media conscious colleague of mine called down Russell from many years ago who built the dinosauroid in truth we have them there birds so we can study dinosaur behavior by studying Birds they are the lineal descendants of one branch of dinosaurs so so we can be confident about various aspects of their behavior when we look at avian theropods and true dinos true Birds the prospect of classic dinosaurs surviving requires conditions that are not conducive to our life on earth basically throughout the Mesozoic they lived in greenhouse world if you can grow tropical plants in the Arctic Circle then there is no issue in relation to temperature control what you've got for the majority of dinosaurs is an incredibly warm pleasant world in fact too hot for mouths mammals were basically crepuscular throughout the reign of dinosaurs that means they came out at night they lived in burrows and when it was cool enough they could they could make they could make life because they trade off being able to generate body heat by losing it to the environment and regulating and measuring the way in which they lose heat to the environment it's like a dripping tap scenario the dinosaurs if they started doing in encounter climatic deterioration and latitudinal zonation they would have contracted first of all in terms of the range and then been out competed by animals like the descendant dinosaurs the birds cannot concoct control their physiology and the mammals so yes they would have survived for a while if they hadn't gone extinct but we'd still be here now dinosaurs could not stand weird world we live in weird world I mean having two ice-covered poles in the history of life on Earth is totally weird I mean if you go back from the late tertiary when was the last time we had certifiable glacial cover the Carboniferous and that was one Ice Pole on the southern land masses after the Carboniferous nothing basically nothing so the world we live in is utterly weird which is hard for us to grasp because that's all we know but the world of the Mesozoic was completely different from the world that we're familiar with today yes in the form of birds and that would have been a whilst while the general climatic conditions would sustain some dinosaurs they would have continued to diversify on the isolated continents post Cretaceous but some but that would have been limited so they apart from birds we wouldn't be sharing them today fascinating talk couple of questions of our mind when you talk about the comparison between elephants and bipedal dinosaurs is that a fair comparison considering the locomotion is different therefore the pressure pattern is going to be different it's not a fair comparison it's it's it's an attempt to say that dinosaurs are very diverse in locomotor habits and style and that has implications on what you think about their physiology I mean I could give you another lecture but basically if you've got a bird-like anatomy like that fast running dinosaur that has implications about its metabolism if you're super large like an elephant an elephant is a non-typical mammal they are heat embarrassed they live in warm parts of the world they can cope in this climate that you know it's not typical of their distribution and they shut down their metabolism they don't have a high metabolism all irate that we have it's like comparing a mouse and an elephant metabolic rate of a mouse is enormous or a shrew enormous elephant they shut everything down they very large volume very small surface area and that's why they're not hairy they're actually trying to lose heat through the body wall and why have they got flappy ears because they use the ears to dump heat to the environment they are heat embarrassed if you race an elephant they overheat so that they have a problem of heat embarrassment now if you scale that up fivefold to a decent size dinosaur they are he's embarrassed the he's embarrassment is a real problem and the that goes back to the problem that the reason why dinosaurs have these air sac systems running through their bodies it's a way of heat dumping their breath was like an exhaust pipe okay thank you at the bone structure there the cross-section of bone you show and you say so an open structure with sort of vascular channels to provide circulation but there's no marrow potential and that surely to the marrow is is what happens when you stir bone starts off that diameter it ends up that diameter right so you've got the fast deposited bone on the outside you've got the remodeled bone in the middle and then the bone in the middle is destroyed to create a trabecular structure which is the mirror so it depends on the dimension of the bone how much reorganizations gone on so be the large bones basically if the Permian mass extinction didn't happen then would have Dinosaurs exists yes because because of the Permian mass extinction all the Permian animals Gorgonopsid um all those Permian animals they killed off and made way for the die for the dinosaurs to evolve but if that didn't happen then we would have the wood of the Permian animals has carried on and become what they did carry on there are a range of Triassic mammal like so called mammal-like reptiles which are very diverse and when you look at their Anatomy they are becoming more and more progressively more and more mammal like as you pass through the Triassic until right at the beginning of the Jurassic the first true mammals appear and how big are they that's mom the size of a shrew tiny little teeth the the what appears to have happened is that there are different solutions to life and different lineages operate in different ways the mammal solution is the heat dumping scenario where you live in a cold controlled environment and lose heat to the environment and have a high metabolic rate if you can fuel that by being active and feeding sufficiently then that'll work but you need a cool environment the things that are best adapted for the environment that dominated the Mesozoic are dinosaurs and I'm like a give you a lecture on the the way in which they removed from their body nitrogenous waste the big point that I'll make is that right at the beginning of the reign of dinosaurs it was really hot and dry the supercontinent Pangea was essentially Red bed environment and under those conditions it's hot it's dry where's the water where's the food it's like living in a desert under those conditions is it good to be a mammal no it's tricky all the mammals are small live in burrows there in ones that are big are camels but they they cheat they're not really mammals they'd all sorts of weird things with their physiology to cope with being big and living in the desert with no food and no water if from the big to make you laugh the big thing about us is we need to go to the toilet we need to piss we need to piss because we produce urea from our kidneys it's water-soluble have you ever seen a bird its leg against the tree and piss do you be honest no what do they produce that you know of bird droppings that is their piss they produce urate s-- they're very clever biochemically and all on the dinosaur linear are better than we are they produce your rates which are insoluble so bird droppings are the equivalent of urine but all the water sucked out it precipitates the urate and the Pooh and the urate paste is what falls on your head if if you live in a desert and you can conserve all your water and you don't sweat brilliant and that's where dinosaurs scored they they don't need much food to start with and they have this amazing conservation system for water and they don't sweat because they have scaly skins I was wondering whether looking at the behavior of the current large monitor type lizards gives us any ideas in relation to the behavior of the dinosaurs a Komodo dragon is actually an interesting animal anatomically it's too large to be a lizard and therefore it's inventing mechanisms in its skeleton which a non lizard like this it's have an amazingly flexible locomotor system a komodo dragon locks that up because it's trying to have its legs underneath his body and sort of bottles with its legs almost like a crocodile and it's actually mimicking a crocodile in many ways so they're actually wonderful example of something that's was a lizard it's built on a lizard bough plan but it's compromising that because it's trying to be as big as a crocodile and they're instructive because it's like producing a series of analogues for the functional constraints that are associated with large size which was solved by dinosaurs not solved by lizards properly and only half solved by crocodiles very good I think with that [Applause]

Channel: The Geological Society

Views: 55,051

Keywords: Palaeobiology, dinosaur brain, fossilisation, Geological Society, Public lecture, David Norman

Id: KB2Q9ARMEbE

Length: 74min 12sec (4452 seconds)

Published: Thu May 24 2018