Dinosaurs of Darkness: The latest on Alaska’s dinosaur research

great well thank you again for coming and I'll just say that I do have some props up here if you haven't had a chance before the show to come up and have a look more prop more small-volume there we go more props oh yeah okay that's across the street actually you laughs I I do have a variety of fossils up here some including like a real dinosaur bone from the North Slope if you want to have a look at that you can pick it up and look at it and a few other things that might make a little more sense after we get into the talk a bit but by means of introduction I was I just sort of like to say that Alaska is a pretty diverse state in terms of its fossils and my job as Earth Science curator and paleontologist is to wander around the wilds of the state looking for all sorts of interesting things and in particular I've literally worked in all corners of the state from down in southeast down to the southwest parts of the state into the interior regions and of course the North Slope and I want to talk about a couple of the sites in two sites in particular in Alaska that are especially relevant to unraveling the dinosaur story because there are a lot more cool fossils in Alaska than just dinosaurs but I'm I am going to focus on dinosaurs and to sort of simplify that previous map here are the major sites for Alaskan dinosaurs in a nutshell and I might point out that again they're widely distributed across the state and some of the the better known sites include the Talkeetna mountains a couple of years ago we discovered a huge new area for tracks along the lower Yukon River which is pretty amazing but I'll talk about that another day and another time I wanted to focus tonight on two sites in particular and the first being the North Slope and this is really where this is where a lot of the really cool action is if you want to find dinosaur bones and dinosaur teeth then you want to head to the North Slope because that's the place where almost all of the bones and teeth and Alaska come from not totally but but mostly and what I want to also talk is the site that we'll see is actually very complimentary in terms of information to the North Slope and that's Denali National Park and Preserve which is practically our backyard and you may or may not know it but Denali National Park is an incredible treasure trove of dinosaur tracks it was actually quite remarkable in fact that we didn't realize for quite a while until 2005 that there are amazing dinosaurs in Denali what's important about those two sites in particular is that they they represent dinosaurs that lived during one of the three major periods of Earth history that we call the age of dinosaurs which we we call that the Mesozoic and there are the three big periods of the Mesozoic era which we you may know about the Triassic the Jurassic of course everyone knows the best thanks to some some movie or another and then the Cretaceous and the Cretaceous period is kind of funny it's not shown on here this this timescale that you see that's done by artist or a troll he has a new one out by the way it's down at the Anchorage Museum it'll be in the new book you talk about that later this this timescale represents the last five hundred and fifty million years of Earth history and it represents all these different names that you see here are actually the subdivisions of geologic time based first and foremost on their fossil content that's the basis for the geologic timescale the Cretaceous period although it's just the short little sliver here actually represents 80 million years of Earth history there has been more time has elapsed since the end of the Cretaceous period which was when all the dinosaurs died till today are more could more time that is the lab since during the Cretaceous period than since the end of the Cretaceous till today that's a lot of time so this is uh this is 66 million years ago as the most recent number for the date give or take a few hours of when the dinosaurs went extinct and it happens to be that the rocks in Alaska where we find dinosaurs upon the Colville River on the North Slope and in Denali National Park right here in Alaska in the interior they actually both happen to be rocks laid down about within really four million years of the very end of the age of dinosaurs about 70 million years ago actually technically it's like 69.2 but you know we won't dice hairs on that one we'll call it 70 and so the dinosaurs I want to talk about today in other words from two different points in the state our dinosaurs that lived there probably the same species because there they they lived at approximately the same geologic time that is actually a really cool thing so let's let's harken back now to the to the Cretaceous period about 70 million years ago and believe it or not this is our continent North America a very different-looking place at that time and I think you can see here this is all the blue of course is ocean here is the North American continent and running right up the middle or nearly up the middle of the continent was a shallow Seaway called the Western interior Seaway now that Seaway was teeming with marine reptiles like mosasaurs and pleasee asuras which I'm not going to talk about tonight and then way up here at the northern end of that Seaway sorry emptied out into what into the Arctic Ocean basin the Arctic Ocean basin at this time actually was ice-free pretty interesting and because of that actually it had some important ramifications for the climate of Alaska and in fact way up here at the North End of this western portion of North America was of course Alaska where these dinosaurs were running around so there's Alaska way up there what's pretty interesting is you are probably familiar with plate tectonics it's the whole idea that continents move we know that in Alaska because we get some rock and roll in earthquakes thanks to plate tectonics and that process has been going on for a very very long time in Earth's history and what's really interesting is that 70 million years ago Alaska thanks to plate tectonics was farther north than it is today so that's pretty crazy when you think about here is a very my very approximate line representing the Arctic Circle which you notice on this map would have actually been south of Alaska period today it runs through basically the northern but the northern third of Alaska so in other words North Alaska was closer to the North Pole how close well it's a little hard to be real precise about that but the best estimates place northern Alaska somewhere around 80 degrees north latitude and for reference today that same real estate is at about 70 degrees north latitude so in other words approximately 10 degrees farther north than today and that's a lot so and some estimates even put that higher than that believe it or not so Alaska was farther north and that being said we still had this amazing pile of dinosaurs running around this is an image of I'll come I'll actually show this image a few times this image by the way was done by artist James havens and Anchorage and he did a spectacular job and you may have seen the original of this at the Museum of the North across the street it's the backdrop for some mounted dinosaur skeletons and what I wanted to point out here actually is that this depicts the scene on northern Alaska 70 million years ago and I'll talk about the dinosaurs in a minute but actually take a look at the plants the plants actually are really important these are very accurately depicted the understory of that area was ferns and then this is the crazy part trees what are trees doing in northern Alaska today much less when Alaska was 10 degrees farther north that's crazy in other words we had during the age of dinosaurs in Alaska polar forests this doesn't exist on planet earth today it was a very different world and these trees in fact mostly were conifers they're probably many cases closely related to something called metasequoia well actually some of them are Metasequoia which is called the dawn redwood which is a still a living species today there's a lot of horse tails and ferns in the understory there were some broadleaf plants as well and what's really cool is this forest that these dinosaurs were living in a forest in northern Alaska and you can pretty much envision Denali National Park as having a very similar kind of a forested environment at the same time as well the reason we like fossil plants is because fossil plants also provide a really important piece of information that we with you know that that we need to know to understand dinosaurs and that is how warm was the climate hot was it a was it up a cold winter a warm winter was the overall climate you know very moderate was it actually very much like today well the plants give you the answer of course part of the answer is just saying we know that there were forests in the Arctic that says a lot but how much warmer was it then and what you can actually do is use fossil leaves of broadleaf trees as basically paleo thermometers and what's neat about this is today if you go around the world and you look at leaves of trees at high latitudes like Fairbanks and you know got your door and you look at the leaves of those trees almost all of them have leaf margins that are shaped like little teeth they're rounded or they're tuesd in other words if you go to the tropics most of the leaves are smooth our entire margin that's called and the ratio in any given forest of tooth or the proportion I should say of any forest of tooth leaves to smooth leaves gives you an approximation of the actual climate the temperature of that forest and so warmer warmer climates more smooth leaves colder climates more tooth leaves and without getting into correct this is the only graph tonight okay kind of studies shows that we can actually put a temperature an approximation of the temperature of a fossil forest if you will based on the percentage of a whole bunch of different leaves that you look at in countin and in document and this was done really well by a UAF scientist named Susie Tomczyk as part of her PhD work here at UAF and she actually came up with the number that the average annual climate in Denali in this case and it's very similar for the North Slope 70 million years ago was about seven degrees centigrade or 42 degrees Fahrenheit that's about the same as Juneau Alaska that's how warm it was in the way northern reaches of Alaska 70 million years ago that's pretty crazy that also gives you some indication of the capacity for climate change that this earth is possible to experience okay so I mentioned we've got the North Slope we've got Denali the important thing to remember here in these two sites being the premier sites of Alaskan fossils is that they vary they have two very different types of data two very different types of fossils the first again being North Slope that's a story that is primarily bones and teeth and we love that there are tracks up there as well but when you go to Denali National Park the story is almost entirely tracks no bones no teeth with a few rare exceptions but almost entirely tracks and at first glance you might say well that's kind of frustrating how do you compare those two but for me actually it says wow this is a great opportunity because the way I look at it which you can do is you can use the information based on bones and teeth from the North Slope to tell us about who was making the tracks in Denali National Park so it actually helps that's something that's very difficult to do a given footprint you can't say that was made by this dinosaur or that unless you have maybe that same species living and found in the same rocks but that's that's not the case in Denali but we can turn to the North Slope to help us inform us who were making the tracks in Denali and likewise we might find tracks because you know think about an animal in its lifetime it leaves millions and millions of footprints but that one animal only leaves a small pile of bones when it dies right so tracks are really important because we have a lot of them so looking at a lot of tracks and a lot of different tracks tells us about the kinds of things we should be looking for in northern Alaska so these two by sheer dumb luck we've got these two sites in Alaska from the same age that have really wonderful complimentary data so what I'm going to do for the rest of the talk is I'm going to highlight some of the the things that we see on the North Slope and then mention what that tells us about the tracks in Denali and sometimes vice versa okay this is the Colville River the biggest drainage in northern Alaska drains the north I actually drains a very large part of the north side of the Brooks Range and you can see it's a pretty wide river and if you look closely there's a camp one of our camps is right there and there's a boat right there that's how we get around on the North Slope we fly in land on a gravel bar put together a couple of boats and then we float down the river and it's it's great on a day like this and probably many of you have been under the North Slope and you know it's not always quite that nice especially in August but this is where we look for the dinosaur bones it's in those Bluffs those rocks they're things something we call the Prince Creek Formation and it's sticking out of those rocks our bones and teeth that we want to find and for many years the premier site for dinosaurs in northern Alaska is this one layer of rock that my colleague Greg Erickson is kneeling in front of here and this is called the Liscomb bone bed now Liscomb bone but it's pretty exceptional it's it's a it's a layer of rock it's only about well varies in thickness but it anywhere from oh maybe 10 to as much as 30 inches in thickness it's a layer of rock that extends many many feet across the outcrop and in you dig into that layer of rock you find thousands and thousands of dinosaur bones primarily of one species and this is um you can see these are the bones right here in the process of being excavated and if you look closely there's a bone right there there's another part of a bone there there's another bone there actually there's one right there this is literally just like imagine taking a bunch of dinosaurs and throwing them in a blender and then spewing it onto the landscape and burying it that's what the Liscomb bone bed is it's pretty remarkable we have been excavating at this site for many years we now have something like six thousand individual bones that we've excavated out of that layer and that's by the way where this bone came from right here and so you know 6,000 bones we we we don't mind passing a few around in fact hey let's just pass around a bone here we can once you start and just sort of pass it around there you go and the type of dinosaur that is in that bone bed is something called a duck-billed dinosaur and duck-billed dinosaurs are very common types of dinosaurs from the Cretaceous period they're probably the most abundant common kind of dinosaur on the planet during the Cretaceous period we call them the cows of the Cretaceous because they were plant eaters and they were really abundant and they lived in herds the question for a long time has been are the dinosaurs in the list comb bone bed the same species as some species we know from down in like Montana and Alberta where I worked many years ago or are they a unique species to Alaska and that's been a big question so well how do you answer a question like that in a word comparison I had a PhD student who worked on this question and spent a lot of time traveling to museums all over North America and looking at all of the sim types of duck-billed dinosaurs and after looking at all this material and comparing and describing every bone in gory detail came up with the conclusion that you know this thing is different this is a different species than anywhere else and so that means we get to give it a name because if we're gonna name a new species of dinosaur we have to write a paper and get it published and then we have to we have to suggest a new name for this dinosaur well we did that and we wanted to use a name that was honoring the the native people of that area the new piak people so talk to Ron Brower about a name that would work well for this dinosaur and after a bunch of discussions we came up with what seems like a tongue twister it's not so bad it's called a grue nelec cooktop against Asst and it's not that it looks worse than it is there's a lot of vowels and you know it's fun but so a grue nelec roughly translates to ancient cure because this is a kind of dinosaur that chewed vegetation it didn't just bite and swallow it actually a chewed food that's very weird for a reptile to do that kook pick is the native name for the Colville River so instances of this so this is the ancient Shore of the Colville River so that's the name and this is one of the right now for named dinosaurs from Alaska and this is a dinosaur species only found in Alaska and this is a skull of of a juvenile right here and we have three mounted skeletons at the Museum where you can see one of them right there so if you haven't seen those at the museum please please come and have a gander so here it is in all its glory adults and juveniles of a grue nelec and this is kind of cool so we've got we've got this duck-billed dinosaur and you notice on its head here it's kind of just kind of flat on the head what's interesting is we found evidence for another kind of duck-billed dinosaur we haven't named it we haven't published it quite yet but this is a kind of duck-billed dinosaur that's got a crazy crest on its head this group of dinosaurs are called Lambeosaurus and we have rather rather cool we have this partial skull of a Lambie Asur Alaska which is really crazy because basically we have two kinds of duck-billed dinosaurs and it's a really ugly skull oh it doesn't look pretty it's gonna be it's tough to study but it does have teeth and it's got a bunch of other distinctive features and everything we've seen so far suggests it's it's also a distinct species but come back maybe next year and I'll have a name for you so now let's look at Denali oh yeah go ahead so our question is if it's eating vegetation does it have molars and grinding teeth and the answer is is it didn't have molars like a mammal but what it had instead is a very crazy thing called a dental battery which is essentially a whole bunch of small teeth that operate together to form one giant grinding surface so effectively the upper jaw was one grinding surface and the lower jaw was another pretty similar to really what a moose does and they would grind when they when they chewed their jaws actually flexed out slightly and it accommodated a grinding chewing motion so it's it it's a really cool story is it yeah it's chewing in hadrosaurs is an amazing and ductile dinosaurs is an amazing amazing subject and if you want to come up later I'll give you some more gory details on the skull here thank you for that question so let's turn our attention now for hadrosaurs in Denali what do we find there do we have the hadrosaur tracks and the answer is oh yeah we got a lot of hadrosaur tracks in Denali and this is how we look for them by the way this is this is the rigors of fieldwork basically you go out and you hike and you look at the rocks and you have to learn how to identify dinosaur footprints so here's a good test for you do you see the dinosaur footprints hmmm ponder that for a minute so this this is Denny Capps he's the geologist at Denali National Park and he's um he's pondering some dinosaur tracks right there and I'll give you a little hint so what he's looking at there is a layer of rocks that are not any longer laying horizontally they're actually tipped up a bit on angle and one of them is a big bed of very coarse sandstone and what what his hand is on there is the bottom of the bed of sand stone that's been tipped up so it's kind of like looking almost up underneath from the ground at the bottom of this layer and I'm gonna give you a hint okay watch this look hey whoa whoa did you see that actually that whole surface is dinosaur tracks the whole bottom side some of them are really nice three toad tracks some of them are all churned up and it's heels and toes and it's a big mess in fact this has been called the dinosaur dance floor and as it turns out it's just a tiny little tiny little layer that is it pales in comparison the amount of tracks in Denali Park are just phenomenal this is just you know another one of these layers it's that this is it's it's a cool spot but we have so much more amazing stuff in the park and those tracks are three-toed their short toes than their broad toes that's a classic duck-billed dinosaur footprint and probably the reason why you might not have recognized that as a footprint at all is because it's doing something footprint shouldn't do it's coming out of the rock footprints are supposed to go into the rock right well yes that happens definitely but here's actually at least two ways you can make a dinosaur track first you can imagine sort of the typical way like we would make walking across the mud surface you stick your foot in the ground and you leave a hole voila you have a track but what happens if that track fills with sediment you just made another track and that track if it weather is out because it's a different kind of sediment like sand is what we call the natural cast it's the in filling of the what we call the true track and I have some examples up here here is a natural cast and you can come up and look at these later it's a relatively small one and you can see it's a nice little footprint sticking out of the rock and when I put this this flexible sill putting stuff on it which is how we make copies in the field you basically make what's sort of like the original track the true track these natural casts are one of the very common ways we find tracks in Denali and that's not a lot of people search image which is probably why I took until 2005 to recognize that there were tracks in Denali but these are some fairly classic three-toed duck-billed dinosaur footprints most dinosaurs not all are three toed and duck-billed dinosaurs have these very sort of fat toes and there's relatively short and squat and if you look at this slab of rock right here there's another one right there we look for these sometimes in landslides where rocks have just basically crumbled out of the mountainside and the rocks are all turned up but they expose the bottom layers of rocks really nicely okay another dinosaur we have now back to the North Slope is a horned dinosaur so a lot of people are familiar with Triceratops the classic kind of iconic three-horn big four-legged plant eating dinosaur we don't have those in Alaska but we do have a relative that is called Pocky rhinosaurus and Pocky rhinosaurus literally means thick nosed reptile and instead of having big horns on its head it has some horns instead of having three big horns it actually has these big gnarly bosses of bone and that's where it gets its name and we have a distinct species here in Alaska and this by the way rate roll who did this exhibit in the Anchorage Museum which is still going on he'd made he always wanted to do this he made a rhino Sorrell actually a colleague of his did bashing through the wall there of the anchorage museum which is very clever this is actually some real bone here so we have this really interesting again plant eating four legged dinosaur and it has a very different kind of a footprint and in Denali National Park in fact we find a lot of horned dinosaur footprints and so here is a is my colleague Kevin May from the museum here he is holding up a cast a natural cast of in this case a four toad packed probably well I can't say for sure it's pachyrhinosaurs but if I had to put my money on it I'd say it's very likely pachyrhinosaurs footprint anybody recognize this stuff right there right there yeah I heard skin or scales exactly these are actually impressions of what I believe to be our pachyrhinosaur or ceratopsian horn dinosaur skin impressions and they're very large they're like the size of almost like dime to quarter size and they're very different as it turns out from duck-billed dinosaur skin impressions which we have also found that you're much smaller and they're only oh I don't know like pea sized scales and these are much larger so found that last summer and that was like oh that's pretty cool no what about the mediating dinosaurs and I'll just say that I I don't have time to get into the detail of all the species that we find on the North Slope but there are about 13 14 species we recognize but so I'm going to kind of hit the big ones here but of course when I speak of big ones this is our dominant predator in Alaska 70 million years ago it's a Tyrannosaurus not Tyrannosaurus Rex which I by the way have some of a tooth up here of a Tyrannosaurus Rex and a claw of Tyrannosaurus Rex you can come up and look at those and we have instead a relatively smaller relative that's been named Nanook soros Hoagland I and this is a pretty impressive beast it was top dog in the ecosystem for sure and the dominant probably the dominant predator 70 million years ago in Alaska do we find footprints of these guys in Denali well I don't have a picture here to show you like I will tell you that last summer I and I didn't get a picture of it we we did find a site where I'm pretty sure we have a Tyrannosaurus sized footprint that could very well have been made by Nanook soros but I will show you some other very cool meat-eating dinosaur footprints from Denali this is this is a really beautiful again a natural cast three really beautiful toes notice the toes are relatively long and narrow and actually right there at the very end of each toe is a claw impression kind of a triangular little mark that represents the very end of the claw of the toes and so again there's a claw of a Tyrannosaurus Rex as you can see they leave very distinct little triangular impressions some of these could be made by young Tyrannosaurus it's it's very difficult to look at a footprint like this a three-toed meat-eating dinosaur footprint and say that's that's of this or that's of that it's really difficult to do but one of the options could be small Tyrannosaurus another option are a group of toothless dinosaurs called ornithomimus oars and ornithomimus oars look like well they call them ostrich mimics and that's what ornithol - or means literally as a bird mimic dinosaur because they do look very bird-like ostrich like and we do have some bones from that group on the north slope and we have some tracks here are true tracks and here's a natural cast of some beautiful tracks that I think very likely could be from this group of dinosaurs yeah the good question these are tracks from the hind foot yeah so these are all the three-toed impressions from the hind feet the front you see décima at the front the front feet the front hand the hands if you will so dynasty eating dinosaurs only walked on their hind limbs they never walked on their front limbs with maybe one weird possible exception and Spinosaurus very good and they they had variable numbers of fingers on their front hand on their hands basically most of them were three fingered Tyrannosaurus Rex was two fingered there's even one called mano NICUs that was one fingered so they do weird things yeah yes and like these are these are big basically grasping hands in fact they have they didn't have a true thumb but they had something equivalent to like a um a prehensile thumb they could think it very great literally grab things yeah so turning back to the North Slope again you know when you start looking at meat-eating dinosaurs you're talking about the dinosaurs that are going to be the rarest and hardest to find because like any predators in today environments they're they're the rarest right you have lots of plant eaters and then you have a much much much smaller population of the things that eat them so you find a lot more moose in Alaska than you find bears and wolves same thing is true for dinosaurs in northern Alaska we find teeth of a couple of two different types of small carnivorous dinosaurs that belong to a group that are called Deinonychus ores which is a great mouthful Deinonychus ores include this one group we call dromaeosaurus another called Troodon Ted's don't worry about the names but we do find rare bones and rare teeth we know the groups are there we haven't quite found enough to name a species but we know that they're there and here's two depictions so this is Troodon and this is basically Velociraptor so Velociraptor made famous by the Jurassic Park movies the sad news is Velociraptor in Jurassic Park actually in real life had a skull about that big and was was was actually only would have come up to about your knees in height so not nearly as big as Spielberg at least initially made them out to be but they're still really cool animals and we have Alaska has its own kind of Velociraptor but but bear in mind you know they're much smaller than everyone likes to make them out to be one of the crazy things about this group of dinosaurs and the thing that makes them recognizable is that on their hind instead of having they have three big toes that they walk that you know on their hind feet but instead of walking on all three toes they actually only walk on two toes and the other toe like this foot here from Deinonychus from Montana that toe has it sports this very scary slasher claw and this is how they dispatched prey is they basically and we have evidence that these were probably pack hunters like wolves that they actually used this very scary slashing claw on their second toe to be equivalent to your yeah like your second yeah right next to your big toe there they had this huge slasher claw well when I started working in Denali I thought you know I nobody's really talked much about those kinds of dinosaurs in Denali and I said we should be looking for two toed tracks in Denali and sure enough I mean literally like the second day out we started to find them and if you have a look at this picture this is this is a what I would call a really good example of a two toed track and if you're looking at that going yeah right here's a little is the same image with a little bit more of an interpretation on it and if that's still a little hard this is the this is a replica of that actual footprint right here and you can come up and look at it and someone to their credit earlier tonight said hey is that a to toe track and this is the copy I made of that original footprint in this in this stuff called SIL putty that we make copies with so come up and have a look at that later and to sort of help you interpret what you're seeing there basically this is what would be the middle digit and this second is so it's kind of like a piece dinosaur right it's like a piece man mm-hm and so that's digit three that's digit four and the second digit doesn't leave an impression in the ground it's held up off the ground and sometimes though you can see the base of the tow an impression from just the very base of the toe right about there it's not always present though that's pretty cool we have a lot of these actually in the park and we even have like beautiful impressions of the claw which is way the heck out there at the end of the toe really interesting and we have a site where there it's dominated by meat-eating dinosaur tracks for some strange reason I don't know why I have no clue but it's really cool the neat thing about this and I'll just answer your question just sec the neat thing about this is that based on the size and the shape of the footprints not only can we say it's from a Deinonychus or but we can say it's from probably one of the two types namely the one we call Troodon and that's really neat because no one everyone anywhere in the world has ever identified for sure Troodon footprints before but I think we can do it here because we know that they lived in northern Alaska for sure what was your question oh are they handling the prey with their hands yep certainly well both they're they would have they would have grabbed on to prey and they could have lifted their foot up and just and flashed / the dinosaur with that claw they could use all four for dispatching their prey yeah they're weapons well they would they would have to chase after them these are very fast running dinosaurs that's what dromaeosaurus or and that's because they could run after their prey and then they would basically as a group probably like a group predators would attack something larger than themselves and bring it down with both yeah with with the hands and the feet kind of scary I know so I think you're getting a picture here that what we have is actually a really neat site both the North Slope and Denali really interesting sites and you know the story is really it's still very much in folding I've got two weeks of fieldwork planned in Denali this summer I've got three works three weeks of time planned on the North Slope and this we have a lot of exciting things happening and just sort of to finish up I'm gonna mention that we have a site one new site right now on the North Slope we call Jacob's bed which is a really amazing site because it's producing a whole bunch of new dinosaurs we've never seen before and they are mostly coming out in the form of very small little fossils but there are types of teeth and bones of dinosaurs we've never seen before in Alaska so I'm going to leave it at that there's more to be said there this is the way that we actually find some of them was we dig out this little thin layer of rock it's like a miniature bone bed this time and then we dump it into a screen more like archeological work actually and we spray it with water and we sit there and we pick through the sediment and I'll tell you if you want cold miserable work stand next to the Colville River when it's like 34 degrees and raining and do that for 12 hours a day question in the back Jacob van Pelt Quizon who was a volunteer and employee of mine at the Museum and his yeah that name should be recognizable here in Fairbanks he's a Fairbanks in and he he was the one who actually originally found this bed back in 2012 I think it was yeah so you know you find a cool site find a cool dinosaur we'll name it after you and I might point out that sometimes going beyond dinosaurs we find all sorts of crazy things and actually we find fossil mammals up there on the North Slope you know what we find we find teeth but we find teeth that yes that is a tooth at the end of my finger right there and that's how you find fossil mammals is you have to screen many many tons of sediment to find these tiny tiny little teeth and if you get lucky we actually find complete lower jaws we're finding amazing stuff and this this represents a new species of mammal and we're actually I dunno what the name of this is but I can't tell you yet because the paper is we we're about to resubmit the paper for final acceptance we hope in the journal but this is a new and unique species of mammal to Alaska which is pretty cool and yeah it was the size of a little mouse but it's actually a marsupial it's in the same group as things like kangaroos and opossums and actually we have like four new types of mammals up there that we're describing the teeth of right now yeah it's from those little shaker boxes that's that's where it starts anyway sometimes these discoveries by the way don't happen in the field we bring back piles and piles of sediment and we pick it under a microscope in the lab and then one day I walk in the lab and one of my students are volunteers says I found something weird what is this and I go holy you know and then I'm not a specialist in these so I send them off to my colleague Jalen neighbourly who is at the University of Colorado Boulder who is and she looks at them and says holy cow swap and then we then we say that's that's pretty cool yeah there's a close-up of that tooth boy it's yeah I squinty hey there's fish - we got crazy fossil fish up there we're figuring out right now we've got paddlefish you've got sturgeon crazy kinds of Pike things related to salmon we're finding bones teeth jaws of those sorts of fish up there as well we're trying to not just figure out the dinosaurs we want to figure out their whole ecosystem what world did they live in what was swimming in the streams what kind of mammals were there what kind of plants were growing there and it's all one big story and you don't want to be exclusive and we're finding down back now in Denali that there's even a few bones there not much frankly it's some but there's not much we're excited to find them Park was really excited that we found him but their little bones from things like duck-billed dinosaurs surprise surprise if I were to guess what I bought web find yeah I'd find a duck-billed dinosaur and that's what we found this is a thin section of the bone the orange part actually is that are the pinkish part is actually the bone shown under special polarized light and for this summer we'll be working here this is a site that we call the Colosseum this is kind of cool so you notice these are big cliffs and see all the little bumpy bumps on the cliff there what you're looking at are layers of rock that have been vertically tipped up almost on end and every one of those little depressions is a footprint there's gazillions of footprints by the way that turns out this is the smaller of two sites we found another site last summer it's even bigger than this that's the kind of discoveries waiting to be made in Alaska so we're actually going to be flying drones over the site to map at the summer with the with a quasi which is the group here at UAF that does a lot of I'm sorry I shouldn't say drones unmanned aerial systems and they're gonna be flying these over the site making a really cool three-dimensional map of this site so bottom line come and visit us at the Museum we have the largest collection of polar dinosaurs in the world at our Museum it's growing we're finding new stuff and hopefully by this time next year I can tell you something else interesting that we found so thanks thanks for coming and I'm happy to entertain some questions yes in the back your research you just trying to find things and then ask questions about them or do you go into your research with questions that you're seeking - oh yeah that's a good question how do we go about our science like that what we do is we start out knowing that oh there's there's a site that's got dinosaurs for example like on the North Slope and yeah we could just go up there and say hey our goal is to go dig stuff up and then when we find something we'll say oh let's make a story about that the way we've approached this site is we look at North Slope of Alaska in its polar dinosaur is the best place in the world to find polar dinosaurs and we say what are the questions that it can answer that nothing else no other site on the planet can give us information on that's the way we approach working up on the North Slope in Denali and so we actually are work up on the North slopes funded by by National Science Foundation and so we have some very clearly stated hypotheses about what we're looking for and trying to understand in in northern Alaska and just to briefly touch on those I mean again partly it's who is there because that ant that's a fundamental question and once we know who's there we can ask are they the same species found lower latitudes if they if they are what is the or if they're not what does that say about the biogeography of dinosaurs up and down North America which has been a lot of Papers written about that so we can actually test that kind of hypothesis we also especially the work I do with my colleague Greg Erickson he he takes bones and he slices them up so that's actually the this dinosaur bone here you noticed was kind of that a flat end we take bones we sliced them up and after we slice them up we look at we polish them down and make thin sections look at them under a microscope and then you can do really cool things like say okay can we can we answer the question how old is this dinosaur and I don't mean like how many millions of years I mean is this animal two years old three years old and we can do that by looking at a whole variety of different individuals and we figured out how to age duck-billed dinosaurs from northern alas and the cool thing about that is if you know how old a dinosaur is and from the bones you know how big it is and you have that for a variety of animals from small to adult size you can make a growth curve Timmons to talk about how fast that animal grew and from that you can infer physiology things like warm-blooded so then it gets to the big question our dinosaurs that lived in northern Alaska were they warm blooded and how does that tie to the big question our dinosaurs period warm-blooded and we're actually we were able to make a growth curve for this new duck-billed dinosaur and it has the same exact growth trajectory as animals it's closest relatives living at low latitudes and much warmer environments what we're inferring is that this is great evidence for dinosaur warm-bloodedness from that long answer to your question but yes absolutely we we go into it with a hypothesis driven sort of approach yeah yeah she's asking if the gravel pits up on the haul road up heading north our sources for dinosaurs and the answer is basically no yeah the places you have to most of those gravel pits are pretty very young unconsolidated sediments and they they might have the occasional mammoth or steppe bison or something like that and they're from the Ice Age but no they don't relieve any dinosaur bones no yes oh so how BIG's the trance or that was found in Alaska Nanook Soros I would say that if I were to put my hand on tops of its hip so a hip height is a good way we talked about dinosaurs oh yeah somewhere in there quite big and we're trying to get a better idea of that we have some bones that suggest it's probably a little bit bigger than it was originally believed to be and then the other neat thing you can do this is cool if you find a footprint of something you say that looks like a Tyrannosaur you can measure like so here this is definitely not a train a sore footprint but um but you've got three toes you can measure the length of that middle toe and then you can multiply basically by four and it's actually it varies usually a little bit more than that it gives you an estimate of the hip height of that animal so tracks might actually provide some information on how big our Alaskan transfer was so we're looking for ever bigger bigger tracks to see how what the record is and we don't have a lot of them yeah in the back there well yeah great how did the Colbert Rover basically get discovered it's a great story and essentially it was by accident like many important sites back in the 1960s geologists guy named Robert Liscomb was out actually on assignment working that stretch of the bluff mapping the rocks and he found some bones which at the time this was in the 19th early 1960s he thought hmm crazy they had some like mammal bones up here I wonder what those are and he threw him into a collecting bag and took him back to corporate headquarters where they stayed for a long time until eventually they were reexamined in one of the geologists said I don't think these are mammal bones and they were eventually given to a couple of different paleontologists who recognize them as dinosaur and the long story short there was that Berkeley got involved with our museum and they came up to the Colville to look for this site and found them and the reason he can find it pretty easily is because there's so many bloody bones in the Liscomb they're just spewing out of the hillside relocated the site and that began many many years of work not just in the Liscomb bone bed in that area in general and these are the northernmost dinosaurs in the world yeah it's fairly common to hear about paleo latitude how close we were to the pole this many geologists helped with reconstructing altitude climatic oh that's a good question and Dave's been out there he knows this area very well we there's I talked to a guy from USGS geological survey who was working on reconstructing the Paleo altitude of the Brooks Range because I was asking him I said I've got an artist who wants to paint the Brooks Range in the backdrop of my dinosaur painting how big do I sell tell him to make them and I I don't know and so this this geologist started speaking in Greek or some language that I really I mean I'm in the geology department I didn't know what he was talking about but it sounded really good in the bottom line is he said you know pretty much very likely the Brooks Range at least at the time which was actively growing when those dinosaurs were there were were probably emergent and they were probably a pretty conspicuous on the landscape and very likely were high enough to support snow so yeah it was I think they were serious mountains roughly comparable to today possibly a little lower that's the best I got but we do know also that the the area very close the area were like the Liscomb bone bed is which was very close to the sea the margin of the sea of course was that you know very much at sea level so yeah yeah over there a Pentium insula that they were possibly migratory implants yeah migration is a great question and that's actually one of the other hypotheses that we're looking at in testing because actually that bone cutting up bones and looking at them we can compare those to lower latitude animals and we can actually come up with some ideas regarding migration from from the would call the bone histology the idea was possibly to escape very well but they may not have been cold but they were certainly long dark winters that these animals may have migrated to lower latitudes to escape escape the harsh conditions but a couple things go against that one of the big ones is that for them to get from eighty degrees north latitude down to someplace where it was even like the Paleo Arctic Circle would have been hundreds of kilometers farther than even say modern-day caribou do on the North Slope and they're the largest the longest they they migrate farther than any other land mammal today and so that makes it difficult we're also have some other really cool evidence now suggesting that it's it seems very unlikely that that these animals could have migrated that far as well so I think the best evidence right now we have says no they stayed and stay put over the winter in northern Alaska and endured four or five months of darkness and how they did that I don't know but I hope they had night lights yeah [Music] oh yeah so what are the things that make this this animal different from others it has to do primarily with the skull if you take everything from the skull back you cut their heads off and throw the rest of the animal away they don't the rest of the skeleton does not unfortunately tell you much but the skull is um different primarily in this bone right here the pre maxilla and also in the post orbital which is the bone right there and also in some proportional measurements that we we look at as well and it was a difficult thing for us to do that in some cases with this dinosaur because most of our information comes from juveniles and juveniles don't always show the adult states but we do have enough adult material to sort of confirm these features and so yeah so it's just a lot of gory anatomy about like little ridges and stuff on the pre maxilla but this is this is a replica so what we did with this skull in the list cone bone bed we find that they mentioned you know the the bones are all disarticulated all the bones have fallen apart but they're three-dimensional and we dig them up so we can dig out like the right post orbital as an isolated three-dimensional beautiful bone then like next to it over a farther we'll find the left denturri of another individual and so forth and we dig up all these individual bones and because the three-dimensional we make copies of them out of end up in plastic and then we can basically reassemble them if they're all the same sized animal into one composite skull so this actually is built of individual bones from as many different individuals as there are bones yeah and that's a lot of work to do that yeah when you were talking about that duck-billed dinosaur chewing you actually said in the unusual hello reptile you have to chew so why you saying reptile - well reptiles are dinosaurs and the term reptile is become a confusing term and the reason for that is because dinosaurs at least the meat-eating dinosaurs one group of meat-eating dinosaurs is ancestral to birds and so technically speaking birds are reptiles for that reason so most of us don't think like that right and if I say reptiles and you're thinking okay I think snakes and lizards and turtles but you're not thinking Birds you're you're omitting a member of a group that cement that is descended from reptiles so we don't so we we don't like to do that we like to use terms that represent groups of animals that are all related to ancestry so dinosaurs are definitely reptiles and we if we use the word reptile now it's understood that it includes birds in that definition and that does represent a true group of animals so dinosaurs are reptiles for sure and birds as their ancestors are too presentation of no yeah so what's going on with feathers and dinosaurs in short yeah and that's so it is true that the artists right now are all freaking out because the paleontologists telling them to start putting feathers on the meat-eating dinosaurs and that's a little crazy you know like thing to kind of wrap your head around but indeed far as we know most but not probably not all but most of most of the meat-eating dinosaurs had feathers of some sort or another so far as we know the the plant-eating dinosaurs including duck-billed dinosaurs and packy rhinosaurus and those big long sauropods with the long necks like brontosaurus did not have feathers so it's still okay to paint those with good old scaly skin and crazy colors but the feathered dinosaurs are definitely almost most of the meat-eating dinosaurs and so yes they have to put feathers on there in fact the fossil feathers that we found primarily come from China and a few other places as well and those feathered fossils are amazing and they show us that some of the dinosaurs in fact very close relatives of things like Velociraptor basically were feathered with the same kinds of feathers as a modern bird they had they had complex asymmetrically veined flight feathers they had contour feathers on their body they probably had showy symmetrical yvaine tail feathers crazy stuff they would have looked you would have had a hard time 70 million years ago going that a bird or a dinosaur you know you just you wouldn't you would be you wouldn't I have a word for it you'd probably called a bird tell it bit you yeah oh boy how about over here sure [Music] - that was you can do some things with teeth the problem with teeth are limited because unlike mammals they replace their teeth constantly through life well we can understand from that study though as replacement rates of teeth and actually how long an individual tooth was in the mouth of an animal because they laid down daily layers of dentin as the tooth grew so that when a tooth grows that the enamel cap grows quickly and then the enamel portion grows at a slower rate from inside through the pulp cavity and it adds a tiny thin layer every day and that's called a line of fauna burner and you can cut open the tooth in the right way and count those and tell how long it took for that tooth to grow and get an estimate of growth of replacement rates but it won't tell you how old the animal is it's not like unfortunately like aging that can be done for some mammals it'd be nice if it were but you know that's one that's a big difference there good question though yeah yeah in the back is there any way to determine whether so species at least may be carbonated through the dark period oh good question did some dinosaurs hibernate right now the evidence globally is we don't have any clear evidence for hibernating dinosaurs but we do have evidence for at least one group of dinosaurs that there's small plant eaters they're called fess Kola sores that were that we're digging burrows we found a few dinosaurs in burrows and there's one in Montana called oryctodromeus which means literally the digging runner and it's as small as an adult size it was only about that big and it's a mention this group called fescue Lafleur's we have a very close relative two of them actually two different species in northern Alaska that are small bodied at least one of them is very small bodied and could very well have dug holes and if it dug holes it could very possibly have hibernated but to figure that out then you need to look at the bone histology again you just slice open bones and animals that hibernate sometimes leave behind very distinct lines of growth that might be indicative of hibernation but we haven't demonstrated that yet you don't have a lot of bones of these things yet but that's an intriguing thought and it's one that we want to follow up on because you could see a fasting period about like tree raising yeah because I was thinking that in the dark most plants wouldn't ephemeral and that's a cool thing is like so what did these dinosaurs do during the winter for food one of the things that we've seen from other studies of dinosaurs elsewhere in the world is that dinosaur is broadly speaking were roughly warm-blooded but you know that there's no like purely cold-blooded purely warm-blooded there's a range of variation in there dinosaurs may have been able to sort of be more not so necessarily warm-blooded but a little bit less than warm-blooded which means that they may have had an advantage if that were the case and having lower metabolic rates and surviving on less food over long dark periods when when they needed that energy and that that may have actually been an advantage for them in some respects so they either would have had to have left they would have had to hibernated or they would have had to just figure out how to live and cope with with poor conditions and you know I'm always amazed that moose survive through the winters in Alaska being big helps being large bodied it helps you you it's called mass endothermy allows you to maintain a lot more warmth in your body so there's a lot of strategies and probably there's more than one answer yeah yeah city prison all fall but the dinosaur Tana yeah good questions all the vegetation like so the plant eaters had to eat something and just like moose deal with low quality forage in the winters here all of these trees up on the North Slope even the conifers dropped their needles they were deciduous conifers as well as broadleaf kind of deciduous trees and we have evidence from from coprolites fossil poo not from Alaska but from other places that suggest that dinosaurs were probably eating things like bark and twigs at least part of the year and that they were surviving off of that so some of them could have survived off of that I'll tell you what I'll take I'll take one more question and then I don't want to hold up anybody if but sure let's yeah it's a good question and I don't there I want to say that I do remember seeing one paper that talked about that with respect to some things found in coprolites but I honestly don't remember what their take-home message was so but but in general no there's not a lot of soft tissue evidence for things like that unfortunately so any rate I will just say that I'm happy to entertain more questions so feel free to come up look at goodies and and ask more questions and thanks again for coming [Applause]

Channel: UAF Summer Sessions & Lifelong Learning

Views: 39,736

Keywords: uaf, uafssll, uafsummer, ssll, discoveralaska

Id: FYynfT3lO7I

Length: 65min 55sec (3955 seconds)

Published: Sat Jul 07 2018

Reddit Comments

[u/Viralclassic]

As a former grad student of Pat’s, he is an incredibly nice and thoughtful researcher.

[u/bherring24]

I'm not really sure why this is surprising since it was far warmer esp in the Cretaceous with no polar ice cap in the north

[u/Xythan]

Worth noting, the title is likely a homage to this...

https://www.amazon.com/Dinosaurs-Darkness-Life-Past-Thomas/dp/0253337739