From Svalbard trilobites to plate tectonics: A lifetime in palaeontology | Richard Fortey

hello everybody I I'm leaving us missin I'm head of the Science Library the proud head of the Science Library and I have the great honor of welcoming you to this toluse dog in the tale estate at the Science Library we have since 2011 hosted and organized a wide variety of events and outreach efforts we have collaborated with all the departments of the faculty of mathematics and Natural Sciences and the Natural History Museum and we have had a lot of great partners both inside and outside the University of Oslo but I must say the collaboration of the science library's own geologist Edina and our event team and the Department of geosciences has been an extraordinarily fruitful one this year plus the last three years have brought us a range of interesting engaging and popular events together I think they are succeeding in building a strong community around the interest in geosciences that reaches far beyond current staff and students and that's a good thing a very good thing so before I give the word to Brittany saw the head of the Department of geosciences let's give this happy Union and all the organizers and contributors of today's event a big hand of sauce so they're all well I'm really thrilled to welcome to this serious Telus lecture my name is Brittany so hopefully I'm the proud the head of the Department of Geoscience and I'm thrilled to introduce this year's tellus lecture to all of you Richard Alan Forte a British parent ologist and he's also a natural historian and writer and a television presenter Forte has a long career as a parent ologist at a Natural History Museum in London and his research interests include above all trolley beads he has named numerous trolley bits pieces and still continues his research despite having retired from the museum which I will say is not uncommon thing for a scientist to do to continue research after retiring and we have some of our emeritus here including Cody Henning small you you are there yes which was married to do not handing spoon which was a call a colleague of Richard Forte in all the days yeah so forty has a PhD and a Doctor of Science from University of Cambridge and he's also an author of popular science book on a range of subjects and there's a little exhibition behind there showing some of his books on one book that the designs library didn't find was there the Roderick master book on money-making schemes or how to become enormous ly wealthy with virtually no effort so yeah so why forty forty has a very long history with the University of Oslo and the Natural History Museum Italian and together with Professor David Bruton they were writing the source of small but already in the early 70s looking for fossil in Cambrian or the Eastern rocks and in particular and troglobites so their professor forty were looking forward to you lecture on the from small Bertrille words to plate tectonics well good morning I have been associated with Norway for my most of my working career I first went to spell Bard in 1967 at with Cambridge University who financed a small expedition where we discovered wonderful new rocks full of trilobite s' which became my PhD thesis and since then I have been back and I'm going to tell a story I'm just going to start my narrative today with just taking you on the expedition to Svalbard the northern part of the vest fits Bergen in the early 1970s where I first worked with David Bruton I did you introduce you to try the bites first because some of you probably don't know what rather bites are fossil arthropods distantly related to the crabs and lobsters of today but very distantly related enormous ly diverse in the lower or paleozoic rocks in general with an evolutionary history of their own of several hundred millions of years so it is quite possible eminently possible to be a historian of several hundred million years just by studying trilobite sand I've spent most of my life doing just that after the 1967 trip I published my first ever geological map in 1968 and this is my first ever geological publication and you can see where the rock sections that we went back to in 71 are in the north of the island and at that time we just matched mapped a couple of formations of rocks I came over to Norway I think in about 1970 to talk about the new discoveries in Svalbard and it was that that led to the north polar Institute bringing an expedition a much bigger one with David and me on board and many others who are still here in Oslo including gunner Hennings maan and curry was referred to earlier to collect fossils from this these localities along in Logan Street a very remote part of the north part of the island so we set off in a large vessel called polar star and polar star dropped us off we passed Barentsburg not particularly photogenic Russian town on the way and we were dropped off with large amounts of supplies on this remote shore where we had to set up camp the only way to get around apart from on the big boat was by little Dory's which had to dodge between the icebergs and david was reminding me just last night that we had a very narrow escape when engine pratically snagged with an iceberg and he could well have been smashed to pieces so this was quite you know challenging fieldwork very windy so that we quite often had to tie our guy ropes to buried spars buried in the gravel fortunately there's a surprising amount of drift wood finishes up on those Valverde's beaches because I suppose of the North Atlantic Current carrying tree trunks up there so there was never a shortage of wood to do things like that and you can see in the background the little Dory that we use to get around and well it looks comforting doesn't it the reason that this area seemed to have escaped attention because it's mostly a raised Beach as so much of the coastal area is up in Svalbard and mostly all you see is gravel and nobody had noticed that along the edge of the raised beach there were rocks outcrop of rocks and these auto vissi and rocks escaped attention until the Cambridge expedition stopped to get some fresh water and found try the lights everywhere so that's why I went back in the late sixties and why we went back again in 1971 there's me looking every inch the Arctic hero and you can see that of course once the wind changes direction the pack ice blows in and you're really cut off I'm wearing you'll notice a very handsome rifle I'm almost certainly the world's worst shot we had practice rifle practice they put a row of tin cans along on the gravel and I had to lie down and try and hit the tin cans with my rifle this of course is case in case and is burn and a polar bear came and I missed all the tin cans and I said I'm very sorry I'm a very bad shot and the man in charge said don't worry when a polar bear comes your shock will improve but which is fine except that I'm probably the only person to have spent too long field seasons in Svalbard and not seen a polar bear I think it's because this place was so miserable and bleak that the Bears didn't even come there the only polar bear skin I saw was in long Libyan and it was on the floor I have to show you our sanitary arrangements one of the things you have to do of course is your business and it's extremely cold but if there's an Arctic wind blowing so we built this nice structure from bits of wood we found lying around which we called the room with a view so you look out to sea while you're at work it was very very well made because this was built in 1971 and nearly 20 years later another expedition went up to the area and they photographed the loo there it is still standing after several decades as it is today it's probably still there in the middle of this rather bleak raised beach but the job of course was to hit rocks and there are some of the rocks and well I don't know if it's true in Norway but in in England of course they used to punish criminals by getting them to break rocks for weeks at a time but we were doing for pleasure even though the weather left something to be desired we whacked and we worked we made enormous collections and those enormous collections at the back you'll see some of the works I've published on these became the focus of my life for at least another 15 years after this time and we added another area of outcrop of these formations to the map the North one you're recognized in the first slide which was the one I did with my original visit but we discovered another area down here to the south of the great ice sheet called vow shall vow how fauna of the same rocks to the south so we now had much more rock to collect so David and I and colleagues mapped these rocks which proved to run from the very base almost the base of the Ordovician up to about the middle of the Ordovician really a tremendous stack of rocks through at least sort of 50 to 60 million years of geological time and that's plenty of time for trilobite evolution to take effect I'm not going to do this particularly in detail but basically the blocky looking stuff is the curtain Riggin formation and that's overlain by The Vow how fauna formation which it consists of much darker lime stones that's what the vowel fauna formation looks like and you can see just how little rock is actually exposed with the Rays Beach lying above it so that's the reason why people must have sailed past four years and years without even noticing rocks there while we were there we explore that new southerly area by making a little sub camp and here's our little cozy sub camp intraday you see we Flo flew flew a Union Jack there to the right not I hope I hope you're in there too overly nationalistic but there was also very small Norwegian flag that was flying and the same tent but the Norwegians won because you can probably see already that that flag is looking a bit shredded at one inch on the right hand side and the the bridge ish Union Jack gradually because of the wind unthreaded itself Oh over the time we were there too we had a little stub left at the end the Norwegian flag was much better made and lasted the entire trip by the by and there's David everybody in those days smoked just about David smoked a pipe which you can see being reflected and that we built this little kitchen filled kitchen to keep out of the wind of course it's never dark so we had to observe rather strict hours to make sure we went to bed at the right time and woke up without getting compile aaja cool clocks completely mucked up and there's three of us that made this and me taking the photograph doesn't look particularly welcoming does it huddling round of fire made from the thumb of that driftwood having had a day whacking the rocks and that's what we do just to show you a little bit of the rocks themselves this is the lower part of the Secession of the curtain riggan formation which a pale colored very shallow water limestone's not great stuff for finding fossils you might say and there's a great thickness of them and finding fossils was really quite difficult in this part of the formation this earlier part of the succession was the last one to be written up and I don't know how many of you here are doing feces or have done theses or had to write our big projects but I can tell you I wrote the first three parts which are on the table at the back of my descriptions of these of what we found there in 19th between 1974 and 1980 we're actually 1982 and I finished the job finally with David in 2013 so better late than never you might say those light-colored shallow water lime stones are followed by a rather drastic change in the follow G to much darker well bedded lime stones look at the snow apparently the snow years have been rather better since since there at one point we actually had to use dynamite to blast some snow off the outcrop so that's what we did more or less all day every day until it was time to go to bed on one occasion I even fell into the Arctic Ocean not a good thing to do with all that ice around I think you've got four minutes isn't that right David but David who keeps a diary every day has a rather disappointing entry for that day it just says you know more fossils collected Richard fell in the Arctic Ocean he saved my life by pulling me out with his geological hammer I seem to remember I didn't find many pictures of the fossils as they were collected in the field but I hope you can all see that most trilobite sand not whole complete things like the one I showed you in the beginning but they malted and fell to bits and here are some of those bits with the matchbox which I see it was pleased to see last night has not changed design in the last 40 years healed sticker so that's what we were collecting this one was immediately recognizable when we found it as something new in fact when I went on the original expedition we just called it Fred so this one became broad-brimmed Fred and then we had narrow brimmed fred and various other friends but eventually you get to formal description and naming of things which is always a fun thing about paleontology and I was lucky enough at that time to be employed at the Natural History Museum in London where I spent a long working life and still have an office so I was actually being paid to do what I would have done for pleasure this is the very first trilobite I described unnamed it was called a pewter and as you if you think back to that first trilobite it looks very different it's long and thin and it has the most enormous eyes pointer yeah that's its eye which fitted onto the side of the head it was a vast googly eyed thing and I'm going to come back if I got time and it's very hard to do a lifetime in an hour to this later on so I'll just go to the cover of the first part of the first monograph I wrote which is up the back this was about Fred and his friends which turned out to be a family Oh Lenny D it's a very well-known trilobite family in Norway where it occurs in the upper Cambrian he only needs ski fur it's one of the most famous rock formations in Norway and Gunnar Hennings Mon who became a good friend and mentor wrote a fantastically good monograph on the Norwegian Olenna D from the Cambrian but the general story was that by the Ordovician the Olenna DS had had their day they've faded out but not in Spitsbergen they hadn't they had a whole new evolutionary radiation which was the subject of the first part the bitter I wanted to get out of the monograph and I can't because I forgot so long time I'm just gonna have to flip through the trilobite but just to show you Fred properly photographed the nice thing about naming speak fossil species is you can give them species names in Latin and Fred became balli Barbie for reasons I could explain later and the species name for this one was sombrero which I don't have to explain so this is Bali Barbie sombrero and there was a whole evolution of Fred and its allies in this rock sequence and I there it's also peculiar dark rocks you saw a field specimen earlier which is just like the dark alum shales of the Oslo region so something special is going on about the Oh Leonard environment and the the most important thing that came out of this work in general was that I realized that trilobite s-- were related very much to the paleo environm the ancient seas of the early or division and the sorts of trilobite she found varied according to their habitats in which they lived the Oh Leonard's had carried on in Spitsbergen after their demise or these reduction elsewhere in the world this special habitat they loved and Fred and it's fret on his many friends were bore witness to that I'm just I'm not going to show you many of them here's another one which is has these marvelous this is not Fred this is a different genus which has these wonderful veins all over it exquisitely preserved really which may have something to do with oxygenation as we'll discover if I've got time to tell you so there was no Leonard environment which seemed to be deep water still water and I believe low oxygen these were specialists very specialized animals that could cope with arthropods that could cope with very low oxygen levels and as we walked up worked up the sections we found that there were other parts of the sections with completely different trilobite s-- now there are over a hundred species in those monographs so I you know I can't even begin to to tell you about them but I can show you a couple of pictures to show you how different these trilobite s-- were this is that was the giant of our trilobite fauna they got up to probably Oh thirty centimeters long and I called it I gave it the generic name Gog which is a nice short name and GOG in English mythology is a giant there were the GOG Magog Hills and I think it may have Nordic origins I'm not quite sure somebody's nodding here so anyway GOG is the Giant and where you found Gog you didn't find the O Lenin's you didn't find the the Fred and his friends you found a completely different assemblage of trilobite including this rather beautiful one which belongs to a family called malady again there's a nice complete one to show you what it really looked like but mostly we were putting things together from fragments because try the bites molted into bits as they grew so this second assemblage very diverse very rich in species much richer in families than the Oh Leonard environment we call the my lead well I call it assemblage or community nowadays we call it a bio fasces that's the current term for these things so we already had deep water probably deoxygenated bio fast he's full of Fred and its friends who lended bio fasces and now he had this nah lead by a fasces with many representatives of these families and some very pretty new ones that's us that's a really beautiful little trilobite about the size of a small coin which was just one of its family that was really abundant sometimes even forming rocks in this other environment which we interpreted as open shelf diverse but relatively deep water because you don't get nice whole trilobite preserved in high energy environments they always get smashed to bits and then there was a third set of trilobite s' characterized in particular by this family the Alina's and these seem to occupy shallow relatively shallow water carbonate mound habitats and they were accompanied by these very distinctive trilobite s' the car or AIDS so this became known as the lead car ohrid bio fasces and there were many other trilobite besides now the unique thing about Svalbard was and this section was that these were all piled up in sequence and you could tell that it was probably under the control of changing fluctuating sea levels when it got shallower you get the shallower bio fasces when they got deeper you get Fred and his friends and the oxygen levels would fall so it was very very important from that point of view and then eventually when we got to look at the very shallow water oh no I should say all of these trailer bites were changing mutually exclusively so they were real bio facets except for one group which looked like this and I did a lot of work on these and I may get back to it these are trial bites with enormous eyes you can I mean I'm sure even those at the back can probably see the eye lenses whoops what have I done I've gone back there we are you can probably see the eye lenses here on this eye these have great googly eyes at the front very unusual to find them complete but that was one that had molted on the C for probably and these were pelagics and I did a lot of work these were trying swimming trilobite its most people thought of trilobite says you know bottom Gravas but these ignored the bio fascists that affected everything else and just were found in all the rocks equally so they were swimming high in the water column rather like shrimps and the very first trilobite i described of a pewter was another one of these so there was a variety of so one was getting a lovely picture of the sea floor in the early all of this Ian with these different habitats with different trilobite sand swimming trilobite swimming over the lot and then we went finally to the first shallow shallowest of all rocks I showed you the very pale colored rocks which had a different trilobite assemblage again particularly characterised by these animals bath earrings another family bath yiridi actually in terms of their species composition these were the least interesting in some ways because they were well known elsewhere this trilobite petit giris nero was first described in 1865 from western Newfoundland western Newfoundland of course being part of the great Laurentian plate so this wasn't news species wise although it was news Spitsbergen suave odd wise which is why I when I wrote the three monographs I started with the Oh Leonard's which were all news and moved on to the my leads which were pretty news and then I had a third part to deal with those Elina di Roy bio fasces and the fourth part well I had to go back and look at these earlier described species so in my own career I went off to Newfoundland and started collecting Billings his original localities to try and characterize these species better and that's why it took me so long to get around to finishing off the Spitsbergen monograph because I had to do a lot of stuff in between anyway these four bio facets I think have now become quite widely accepted and the point was that when we were doing this work in the late 60s and early 70s when I was a research student this was just the time when plate tectonic theory was taking off and it made complete logical sense working with John Dewey for example in the University of Cambridge to interpret these bio fasces in terms of the edges of ancient continents you can imagine the bath yurid fasces this sort of thing in the extreme carbonate platform rocks and as you went off the edge things got deeper the species composition changed until you eventually arrived at a deoxygenated layer where the old Leonard's were thriving in other words you could relate these to plate tectonic patterns and once you did that it helped understanding with the dismemberment of Pangaea which up to that time people who thought was the earliest who would take plate tectonics I'm just going to show you instantly other fossils that turned up this is a strange Micro for so I recovered by acid solution which we tried as an experiment and various interesting things came out which I'm not going to talk about this one Janos Spiro it came to be called I wanted to call it trumpet I teased because it looked like a trumpet but they wouldn't let me get away with that was one oddity and then we started finding trilobite larvae this is a this is what a trilobite looked like when it was about a millimetre and a half long and from this stage they grew multi molt till they got to the mature number of thoracic segments and then they continued to grow but without adding more segments so it's a whole nother story which I'm not going to tell you about my involvement and others with trilobite growth stages but we had everything there in the Svalbard succession so I started taking the same time slice around the world and I'm just gonna take you on every quick travelogue some of the other places I went to you're entering the loneliest town on the loneliest Road in America Eureka Nevada this was the North American platform which I wanted to investigate to see how it fitted in with Spitsbergen there is Eureka Nevada a boom and then bust gold town which is miles from anywhere and surrounded by a quite a lot of orders in rocks and I have to say that there were a few things that automatically amused me I've I get to laugh but I actually went back there to the same locality in February this year and I didn't put it in but I found another slide of me standing by the same sign looking pretty near death myself at this stage anyway the point was I I found I could apply the bio fattie story in Nevada pretty well I went to the middle of Australia you could be forgiven thinking that's Nevada where I also described the trilobite I had to encounter the world's nastiest bush spinifex they have silica tipped spikes and if you sit on one you'll know about it for weeks I even went to the Sultanate of Oman this is me looking appropriately desert if I'd where people say you seem to go to the most barren looking places to do your fieldwork and it's true if I wasn't working in the Arctic desert I was working in the desert desert but the point was I was building together a patchwork of different environments and sites where the trilobite s-- lived in order to make maps and I even went to back to Wales you know very near home it's a nice welsh coast and to my surprise I found that the rocks contemporaneous with those in Svalbard was still to be found in Wales as well we made many new discoveries of trial by it's like this one from Wales which were utterly unlike anything that we found in Svalbard although about the same age in other words you could use try the bytes to map out how the continents were and that's where the plate oh I had narrow skirmish with with death and several occasions I've talked about falling the Arctic Ocean this was even worse I went to China at one point where I think David witnessed this as well I was stunned by the world's largest Hornet which is this thing and we only doing field work you know as usual bashing rocks and this thing crawl up inside my jacket and didn't Mike being jiggled about and stung me on the side and this was in 1983 when there were no doctors really to speak of in China and I was taken I was in terrible pain in the world was swimming I was taken to a nearby town where I was laid out on a table and my wound would sliced and blood spurted I don't remember any of this David probably remembers it and then as I hate when I came around they said here we treat combination of Western medicine and Chinese medicine I thought thank God for that and they said here is aspirin that is Western medicine the rest of it was a sort of seaweed poultice but I didn't die I'm glad to say so let's get back to the science of it this is a sort of model which was published in the 80s which actually had a lot of circulation at the time there's still you know if you look on Google whatsit it's quite quoted this is a sort of model of how you map trilobite faunas onto constant continent distributions so you have let's imagine I think probably the simplest thing to do this stage is to take the lower one if you have two continents left and right at different latitudes you'd expect the shallow waters to develop very different habitats one would be subtropical or tropical one would be polar or cool completely different conditions for evolution and that's where you should find a real signature for an ancient continent there will be very few trilobite it's in common between those widely separated latitudinal spread areas but as we went down the profile into those different bio fasces we found when we got to the Oh Leonard fasces that you could actually find similar species much more widely spread in other words I characterized them at the time very simply as marginal foreigners which were not necessarily the best way of defining continents but were a very good way of defining their edges and the NIE lead the intermediate one had partook of both sides some endemic some more widespread whereas plankton of course if it was at the same paleo latitude could be the same everywhere but if it was a different paleo that if you did expect the planktonic trilobite s-- to be different simple model but it applied very well to solving some of the Paleo traffic problems Geographic problems which were happening at about the same time this is a reconstruction of my old professor Whittington on what he called trilobite provinces of the North Atlantic region you'll see greenland there and there's fowl bird right at the top Newfoundland which I've already mentioned down the bottom western Newfoundland and the trilobite s-- they're numbered were west of the line AAA all seem to have something in common lot in common Baltic ah the Baltic trilobite s' 10 to 12 on the right were different in relatively shallow water sediments and they're not numbered here but South for Britain and into France and actually into North Africa they were all different again three different trilobite sucks to pose very close together now so that Pangaea reconstruction was rather mysterious you know how could these things be so different yet so close the answer became quite apparent that of course after two zou Wilson's famous insight that the Atlantic had both closed in Pangaea times but was was open again back in or near Atlantic back in Paleozoic or early Paleozoic times suddenly all this made very good sense in terms of those trilobite bio fasces so that's what happened by this is from a paper that Cox and I wrote in about 82 which we'd separated latitudinal II the shallow water faunas the diagnostic faunas trilobite s-- of the Laurentian continent in the north there of this reconstruction with Spitsbergen just peeping in on the right from the baltic trilobite switch are very familiar from the Oslo region and from Sweden and from the Russian platform on the right there from broadly gondwanan forms in pink which included most of Britain and everything lying to the south and east down to Morocco and beyond thereby opening up and I happened to sit by and then being coined as a term for an ocean famished ocean but we introduced turn quests to separate Scandinavia Baltic Oh if you like from the South early ones this has become of course infinitely more refined and it's not my story today to tell you about this for example truant all's fake who's here today did work that showed that Baltic er was probably rotated during this this time so it would look basically upside down at this point it doesn't make any difference to the foreigners because they're rotating around the similar central axis so we began to weave in the bio fasces story into the story of paleo continents and as time went on this got more global I could personally oh there and just showing how it matches on to litho fasces the rocks themselves but you'll notice some rather by ambiguously term marginal plastics the marginal belts around the edge which was at that time extremely unrefined but that would have included the equivalents of our deeper water but rather by at bio fasces well my peregrinations around the world had by then paid dividends so I could map on using those general principles what you saw for example across the Ordovician continent of Gondwana which at that time was much reduced from Pangaea bright green in today's West is that part of Gondwana I was mentioning on the previous slides which includes Britain Spain Iberia and Morocco the polar positions but why then were known it was known that these must be cool surrounding the Ordovician pole of the time but the continent was sufficiently large the ancient Gondwanaland continent to take us all the way around through Asia to eventually Australia where I'll talk about on the bottom right which is I've shown you I'd visited where the shallow faunas were different from those of Eastern Gondwana was Western god one on this map not surprising because ones that the the tropics and the others of the pole but they were in probably in continuity so in the Middle East you'll see some stripy stuff and that's where the two foreigners integrate and intermix so this for you know this actually fitted extremely well with reconstructions at the time and all around the edge you'll see those sort of plastics symbols which is that those marginal formal belts with the deeper water bio feces and although I'm not going to explore it today we mapped these very extensively and it seems to have worked rather well as a way of defining what is the edge of something meanwhile of course the reconstructions were getting more and more sophisticated so by the time you get into well into the 80s particularly into the 90s it was realized that the world is much more complicated than just simple major tectonic paleo continents they're all surrounded by much more mobile areas some of which have independent histories and here you see one of the reconstructions which shows the northern what was the northern part of Gondwana splitting off as the micro continent of Avalonia and having its own independent history opening up the rear koushin behind so as usually in science starts off deliciously simple and gets more and more complicated ah oh right okay just to summarize the influence of these terrains as they would call the marginal independent minded pieces of continent you get something like this where you might get a shelf island of course you're going to get subduction zones around these ancient continents to which throw up volcanic islands and those islands themselves may have their own endemics but much more likely will partake of the faunas from one continent a neighboring continent or another it can get quite complicated and there's some of the subduction zones that were marked in in one of the reconstructions a few years ago which introduced these terrains into a kind of geological context there's some maps I think from the 80s showing the departure of the abalone incontinent from a rather much more complicated this time situation on the Gondwana and core but the fossils help all the way along to document exactly what's happening and I for example was involved in a large debate about a great bit of this of Argentina called the pre Cordillera which thanks to trial rights I think we can almost entirely record what happened to it during the Ordovician that's just a map not to enlighten you but to confuse you of Scotland which was part of them a lot of it part of the mobile area at the edge of Iapetus showing its division in two terrains which has been done by a lot of David bruton's colleagues up in Scotland in particular the principles involved are quite simple though I think this is where the fossils begin to have limitations and it's very important if you're trying to sell something to make sure you don't over serve it for example those little blobs are we imagine marginal terrains with their own independent histories if you had a situation like a where you've got a large paleo continent and the edge of the continent is more or less parallel to lines of latitude and therefore climate you could move a marginal terrain the little blob a long way without noticing any difference in the Faunus they'd just be recruited from the adjacent continent so they're the fossils are no use really and telling you exactly the original position if on the other hand you've got a be situation where you've got changing latitudinal belts as you go from left to right as you shift the terrain northwards or northwest woods northeast woods on this particular diagram you're gonna move fossils from the orange zone to be adjacent to the green zone with different foreigners and you'll be able to detect it that's exactly what happens for example in the marginal terrains around on along the Californian coast as the Pacific plate shifts things northwards you might of course have an island that is more or less between the two major continents at different paleo latitudes as in sea and if you're lucky it will recruit equally from green and from orange so you'll find a mixed fauna in the shallow water fasces on the island which will locate it somewhere between the two in the middle of the ocean rare actually I think but David and David Harper had a foreigner from Holland was it Berlin Hollander which has exactly in the one of the naps here in Norway which had seemed to me to have exactly those characteristics of a more or less perfect admixture of North American and Baltic so that was probably an island that started life mid-oceanic or close to mid-oceanic and the final case is of course if you have very similar looking for as at the same paleo latitude with an island halfway between which can recruit from equally from either side but if they're the same on either side you're not going to know where that was so the in other words what I'm saying is these terrain faunas have to be treated very critically with intelligence to work out what they actually mean whereas the contents I think of relatively transparent and easy to understand well one of the great things you can do if you've got a really good continental reconstruction agent is you can understand short term changes this is one that I worked on a few years ago at the end of the Ordovician I detected I think a shortly a phase of global warming not everybody agrees because I've already talked about where the pole is on the Gondwana continent and this is a Gondwana projection for a brief period in the late Ordovician suddenly they were interloper trilobite s-- that i heard earlier histories either in the platform tropics of Lorenza on the left or even in china tropics on the right they suddenly pop up in unlikely places like Sardinia where you've never had a sniff of them before I'm going to give you chapter and verse here there's a genis called over Luke Ellis quite a pretty Chinese trying to bite very distinctive pops up in Sardinia and indeed in Spain for a very brief interval it must have moved following a warming event from where it was happy before and this one came the other way from North America very distinctive looking thing called Helle O'Meara which had had a previous 40 million year history on the Laurentian tropics and suddenly pops up in Sardinia global warming I don't think anything else can do it so there are all kinds of ways in which this sort of bio fasces model can contribute to the science I'm just going to now very quickly talk about some of the other ways that's what I started in Spitsbergen have led in different directions I've talked about pelagic trilobite it's there he is again off the puter my first-ever trilobite and i spent a lot of time looking for things that look like a pewter these are other pelagic trilobite all with these hypertrophied eyes and I really I tried to follow these around the world as well and it turns out that at least three different groups of trilobite learned to be swimmers and some of them seem to be like keralite as I showed you earlier seem to be epi pelagic others seem to be compliant to the edges those marginal sites of Paleo contents and were probably mesopelagic and I had a postdoc who it is a very elegant piece of research showing that if you do measurements on the eyes they're consistent with what you can do on the measurements of eyes of living arthropods which sort of proved this particular theory whereas the EPI pelagic ones of course could spread all the way around the world but at the same paleo latitude so this is one of these global reconstructions the top one of the Ordovician earlier part of the Ordovician and all those numbers show this trilobite Kerala nighties with the big eyes that I chased around the world and you see it follows beautifully a paleo tropical course except for one horrible one down there at number five so something's going wrong there and I'm not sure what it is but I bet the trilobite it's one they help to sort it out and that just for comparison the bottom one is a living pelagic ostracod which again follows largely a period geographical equator so you can interweave the pate the point is you can interweave bio fasces and bear geography into into a much more dynamic picture of the order received world and I want to go back briefly to Fred that was a reconstruction of broad-brimmed Fred the first ever the trilobite I showed you collected in the field and the black lime stones rather peculiar trilobite for an advanced order this team trilobite because it's got a lot of thoracic segments as you can see rather large number very wide now under each segment a trilobite had a walking leg and a gill branch so if you get lots of segments you get lots of gill branches now I've already mentioned why I thought there these lived in oxygen deficient environments like the Oh Leonard shales of this country so here we have similar looking features but what were they doing or how are they living in this low oxygen environment another thing they all have is tremendously thin shells these are not there they are not being frightened of being chomped up by an otter lloyd as they get out of bed in the morning they're living somewhere that's fairly safe and the shells of course the cuticle oil should call them are there to seat the mussels but they wouldn't be useful to to seat very strong muscles for strong swimming so I think these were rather sluggish benthic animals but living on this deoxygenated sea floor did they have a special life habit that's to show you some other Oh Leonard look at the number of segments on that one for an all of us in and some of them develop these extraordinary bulbs at the front of the head which are like no other trilobite there's another one these are actually Welsh ones once I found in the equivalent offshore strata in Wales and that one's just to show you the the little filaments that form part of the breathing apparatus on these Oh Leonard trilobite s-- so I think they had multiplied limbs multiplying Gill elements and that enabled them to live in this particular environment but what were they doing there and one theory which I espoused I won't say to universal acclaim was that they were cultivating colorless sulfur bacteria there are a lot of organisms today that live in oxygen deficient environments that grow salt colorless sulfur bacteria they either feed on them directly or sometimes they're actually living in the guts of the animal they Teeter always on the edge of completely oxygenation but they need sulfur to feed the bacteria and sulfur if any of you have split a lump of stink stones in the Oslo area you'll know what I'm talking about they really smell sulfurous as did the Spitsbergen rocks remember that David this is from a living clam with this sort of habitat habit and habitat and those little round things are all the bacteria this clam grows and it lives in a burrow you can go down to the sulfur zone and if it really thinks it's going to die it comes up gets a bit of oxygen and then goes down again so I suspect that these only needs learn to be bacterial farmers back in the or division well certainly in all of us Ian and presumably by extension back in the Cambrian here in Norway and that's why you find lots of them but usually only one or two species those the only things that can cope with that particular environment as opposed to the NIE lead very diverse or the Eleni choroidal or eaten bath yurid environments can you find brood pouches on living arthropods yes you can I think those bulbs could have been brood pouches for the trilobite to get the babies up to a size where they could grow their own souther bacteria and certain ostracods living and extinct do much the same thing well it's quite fun to speculate so I was well you can see it the trilobite have taken me around the world eventually took me to Morocco where I teamed up to make a TV programme with David Attenborough which led to another phase in my life which I'm not going to talk about so this is that's a segue as I think you're supposed to call it into just looking at one or two Moroccan trilobite these are Devonian so they're much much than that's the albergue once this looks fairly ordinary from above but if you look at hit sideways it looks like that it's the most extraordinary I highly developed eye but it's not 360 degree vision like the pelagic ones this only looks sideways you can probably see it's sort of a curled flat cylinder we found this a few years ago and I realized that this trilobite was unique in having an eye shade which I hope you can see the question is you know how did that work and we did very simple experiment really to sort see how it works if you shine a light a parallel beam of light on the side of the eye it's well illuminated and that's where the trial of I could see because each lens saw in a direction perpendicular to the pole of the axis of the eye lens so that's with looking a trilobite on the left that's what the trilobite how the track would see the well if you turn the light and bring it till it's vertically above the animal it instantly cuts out shades the eye and really it's no different from you know those of you who've been on the African plains or something or even you know a high mountain if you want to see something distant you want to cut the eye the incident right out from above I'm already seeing you much more clearly for example by doing this and then you can pick up more distant objects easily and you can you can show that the way this is constructed also meant that it had just as acute vision distally as it was proximally which is why it had this peculiar parallel sided Tower for an eye so this is the first and of course a meeting somebody finds a second but the first trilobite with an eye shade and obviously to this animal eye sight was extraordinarily important it wouldn't have been some people have claimed I don't think nocturnal it was probably diurnal and it was almost certainly a predator with that kind of contraption attached to it and I've already briefly seen another extraordinary trilobite that the Devonian went in Morocco went mad spiny trilobite it was there late evolutionary radiation of the group so people who'd say the trilobite wrote their acne in the Ordovician and then they declined completely wrong they had another great splurge of doing wonderful things in the Devonian these are three different species of one genus valise or UPS and the first one when the first one was brought in to me at the Natural History Museum I thought it was a joke because the Moroccans were quite famous for faking trilobite so I assumed it was a fake more fool me because there that's what they're really like and when I went with Brian chatters in to Morocco we discovered not just one but three species of them and there's a fourth one that nobody can afford to buy which I quite like to name but of course I always finish and I will shortly my trilobite talks by saying well what on earth are these trident for and i usually get from intelligent audience like yourselves i usually get a lot of suggestions about well well the silliest one of course is that they used them to spear fish because the trilobite mouth is actually back under the head and that would be like the donkey that was forever trying to reach the carrot you know the fish would never reach the mouth but there have been other ones generated electric fields perhaps stirred the sediment up if you look at them sideways you'll see they even have different profiles you see that one's the lifted up in the air as to where and then tips down distally that one's already on the ground and and so if that wanted to walk along it had to lift its trident as i call up in order to be able to just progress across the seafloor so they said really is a bizarre structure and so i offer a small prize you know to get to somebody who comes up with the right answer and i thought i'd finish today by saying you a specimen I came across this February in the Houston Museum but of course the one I haven't mentioned yet is that they are secondary sexual structures where the obvious comparison with such things as rhinoceros beetles which can have a variety of different shaped appendages at the front which they used to joust to fight off competing males mostly but how do you prove any of these you see these are all it's not like trilobite bio fasces you can quantify that you can't even go there but this is what I found in the Houston Museum on display it's one of the long shafted China Trident bearers and I'm assure that it is not a fake and it's got an extra supernumerary and extremely embarrassing tribe Tainan it's trident now the interesting thing about that is that it actually rules out most of the speculation at a stroke for a functional explanation that if this was trying to function in a very direct way in feeding for example this would completely disrupt any of those normal behaviors so what it does is reduce you really I think to the only leaving the the sexual answer in play that this has to be a secondary sexual structure and then I've just only published this yet it's only so you hear it here for the first time in public I then done a bit of research on second similar secondary sexual structures or in other organisms to find out whether animals you if you're going to reach maturity right you cannot have a functional a dysfunctional appendage which is used in feeding for example so it has to be something that operates later in life you can find photographs online of malformed antlers in deer I've found some photographs of rhinoceros beetles that have gone wonky there's one with us with a split fork rather like our Trident and you can find examples though most of the collectors don't throw malformed ones they throw them away that I found examples with a third trident and they a third branch and they can function perfectly well as functional adults whether they get a mate or not is another question but the point is they can grow up to the point where they can use them so I think that this wonderful specimen unpublished really does show that these particular traffic fights evolve these complicated secondary sexual features and presumably those three different tried ins were useful to distinguish three different species in a second which is very common among these sorts of structures in nature I was going to pass on and I haven't got time now to talk about my life as a as a popularizer of science and I really can't do it because I talk too much about the try the bites but all I hope I've said enough for you to pick up the idea that if you're lucky enough to have the sort of life that David and I have had doing field work going collecting specimens and so on meeting interesting people it makes for a whole series of narratives which is a way of enlivening the science you do now I've I have a separate lecture which I won't give you on what I think are you know how scientists ought to communicate better the trouble with many scientists has communicated is their lives have spent in pursuit of proving a theory that they have so the theory is always center of their perceptions so they will explain you know how I got to understand the deep seismic layers but from a theoretical aspect well most readers approach things through narrative so my approach which I really I thought did best in this book which starts this is why I mention it particularly today the beginning of this book chapter one is an account of my first ever expedition to spell barred with one other person where we found those trilobite s-- and i use that to explain what every book has to explain getting geological time and rocks accession but through the story of that particular expedition so if I leave you with a message it is that well first of all that I hope I persuade you do the trilobite SAR sort of infinitely interesting and one of the saddest things is that it's very hard nowadays to finance a trilobite person like me in a museum there are very there are fewer and fewer of us because well it's not all about modeling although you can bring modeling into it which i think is slightly regrettable but anyway I hope you've enjoyed the talk thank you thank you very much Richard certainly I have to look at trilobite sinan other way that I've done to now I think we have room for a couple of few questions the distribution of trilobites in in paleogeography and across the continent do we know or do you know anything about the larval stage how long did it last you know in in in other animal groups in the sea we discuss how far they could swim and then blur the plate tectonic history yeah that's a very good question of course the first thing to say about that if you're a larva and you're dispersing to someplace and your adult stage is adapted to say living in shallow water tropical limestone's it doesn't matter if you can disperse a long distance if you land on a cool water sandy substrate you're not going to survive but the deeper water a Lenin's that I was talking about some of which seem to be very widespread presumably were capable of spreading at the larval stage anyway or even the mature stage around the edges of continental plates cross whatever narrow straits were left and get around to the other side if I can put it like that as far as the trial by morphology I've shown you a larva some apple are supposedly pelagic they would possibly spread further others seem to have more direct development so they wouldn't spread far at all so I think again it depends on habitat and distribution but it doesn't alter the arguments about dispersed continents with different environments on either side take one more question about some of the things I have said in Morocco is kind of like vulcanic mouths like clay mat and it is completely new new foreigner of trilobites that like it's like very hard to say not eyes and it seems that they live a little bit in like deeper and yeah I haven't that's a good question I in case you didn't hear it there the gentleman refers to some new apparently deep water mounds in Morocco we're blind trilobite are found I didn't mention its day but I've already distinguished a particular deepwater habitat which is below photic zone where trilobite s-- were quite happy but many of them became blind secondarily blind we called it the ethel optic assemblage and that's another trilobite habitat and the peculiar thing about this is of course you find the blind ones which wins the on the sea floor but in the same habitat you can find the swimmers which were living in the photic zone above so you get a strange combination of giant ID trilobite s-- and blind ones in the same rocks which is very distinctive I might add that none of the pelagic trilobite I think survived beyond the Ordovician so we don't find big eyed goggly swimmers in the Devonian okay okay Richard I think we could have a full day's seminar with you with all the topics that you have raised now and I'm really and for those of you that would like to hear it once more there will be a seminar tomorrow at the hartley repeating this but not hardly repeating but a good thing can never be told too many times so when will it be at 7 o'clock tomorrow yeah so this is to keep you warm and a small thank for your presentation here thank you if I go back to Spitsbergen I might use it I heard that English houses can be rather cold too so it could be nice with some weed rule thank you thank you so next Wednesday it's a game star through the studio we'll talk about climate and yeah climate system what's the one more thing I should say yeah and it's a party for the VGO science department in the evening so everyone is welcome those of you haven't signed up yet you still welcome so thank you everyone for attending and coming here and thanks again to Richard [Applause]

Channel: UiO Realfagsbiblioteket

Views: 1,527

Rating: 4.7647057 out of 5

Keywords: Richard Fortey, Trilobites, Svalbard, palaeontology, geoscience

Id: pMBJVuFkr-s

Length: 65min 53sec (3953 seconds)

Published: Tue Nov 13 2018