Dinosaur Eggs & Babies - Full Program

for 140 million years one group of animals like no other before or since dominated all of Earth's terrestrial environments we know them from their bones fossilized reflections of their once massive bodies they are the dinosaurs we feel it deep need to know more about them why have dinosaurs so fueled our imagination perhaps it's because these seemingly indestructible giants are now extinct perhaps it is because the predator clan of dinosaurs speaks to the dark monsters lurking in our subconscious or perhaps it's because of their immense almost unfathomable size in the last 25 years paleontologists driven in part by the public's dinosaur mania have begun to focus less on finding and describing new dinosaur species and more on asking questions about how dinosaurs lived and developed about their lifecycles their origins and evolution everything you'd want to know about the behavior of any living group of animals today in this program we are going to see what the newest field of dinosaur study the investigation of dinosaur reproduction has to offer it is the fascinating examination dinosaur eggs nests and babies so what exactly is a dinosaur it may sound strange but the question is not so easily answered do the fossils that populate the world's dinosaur exhibits belong to one large natural group Dinosauria or are there really a multiplicity of distinct groups meat-eaters plant eaters flying pterosaurs and birds each belonging to a genetic order unto themselves dr. Robert Bakker has been at the forefront of the new dinosaur theories for over thirty years his ideas have revolutionized the way we look at Dinosaurs when he looks at dinosaurs he sees one large grouping like branches on a bush don't you love it this is a dinosaur is a dinosaur thigh here we are at the knee end and up the shaft of the middle thigh and way up here the hip socket this is a big guy as the Barriss or run maybe ninety a hundred feet long a little head at one end long skinny neck massive torso with elephant-like legs an incredibly long dangerous whip-like tail the dinosaur family tree has so many species in it it's more like a blueberry bush and the first cloud of species the first tangle of branch lengths is this guy the long necked brontosaurus also called sauropods brontosaurus Brachiosaurus supersaurus all gigantic all pinheaded or long in the neck all totally herbivorous there are two other great clouds of species the meat-eaters and the big dinosaurs we're going to see those guys inside second big cloud of branches these guys here's Protoceratops this is a beaked dinosaur also called a bird hipped dinosaur as the standard big dinosaur eyes and big dinosaur nostrils but it's got a beak for biting plants these again are plant eaters Triceratops is a big cousin the duck-billed dinosaur is a cousin once-removed and kylo soars those dinosaurian tanks during this group too and the last of the three huge clouds of species are the most famous the Raptors and Rex's the meat-eaters this is Velociraptor a little guy a little carnivore with a big brain found side-by-side in Mongolia with Protoceratops the beaked plant eater these guys go from heads this big a really tiny Raptor to heads five feet long the size of t-rex these guys are the natural enemies the carnivore the natural enemies of the big dinosaurs and the big carnivores the natural enemies of the gigantic long necked brontosaurus and those are the three great clouds of branches in the dinosaur blueberry bush although dinosaur bones were undoubtedly found by humans throughout recorded history dinosaur collecting began in earnest in the American West in the late 1800s it was during this period that the collecting techniques that are still used today were developed many of these early famous quarries still produce new bones even after a century of collecting throughout the 20th century teams of paleontologists embarked on expeditions that combed the planet looking for new dinosaur discoveries at the same time as dinosaur bones were being collected footprints of dinosaurs were recognized as a distinct part of the fossil record here was direct evidence of actual dinosaur behavior Martin Lockley is the world's leading expert on dinosaur trackways first it's important to remember that the tracks were made by the living animal when it was living and breathing and moving so it's kind of like a movie of the activity of the animal where's the bones tell you more about the dead animal how it died where its skeleton ended up particularly I think with tracks we can get some kind of idea of what the flesh is like on the foot if you were to put the foot skeleton in here or stick it in the mud it wouldn't look the same as the track as it doesn't have flesh on it the other thing that we can learn from tracks is how fast the animal was going whether there's like a long step or a short step so tracks are very useful for estimating the speed another thing sometimes we find more than one dinosaur going in the same direction so this tells us something about social behavior whether they were gregarious or whether they were wandering around solitary on their own perhaps the most social of all behaviors centers on reproduction mating and rearing young we know that for mammals and birds mating can involve complex course shapes and territorial struggles while caring for young invertebrates varies from a multi-year process with many mammals to a leave the babies on their own strategy of fish and reptiles so what about dinosaurs how did they do it the idea that dinosaurs were egg layers reached the public's awareness as the result of the great American museums expedition led by Roy Chapman Andrews to the Gobi Desert in the 1920s Phil Curie retraced Andrews expedition in the 90s it wasn't initially obvious that fossil eggs and dinosaurs went together the original dinosaur egg discoveries were actually made in Britain in France in the 19th century but at that time they didn't recognize that they had dinosaur eggs they were almost invariably identified as bird eggs 1920s saw the American Museum of Natural History's expeditions into Central Asia and they found dinosaur eggs they also didn't recognize what they had the first year they picked up one of the eggs and they thought it was an interesting bird egg but the second year the Association was so strong between dinosaur skeletons and nests of eggs that they couldn't deny it anymore these were definitely dinosaur eggs they even found one site where there was a dinosaur laying on top of the eggs they thought it was predatory dinosaur eating the eggs off one of the plant eating dinosaurs but ultimately they turned out that that was an incorrect assumption it turned out to be the very first Oviraptor on a nest of her own eggs so these things were all found in the 1920s and I changed the way people looked at the discovery of eggs even so it took a long long time before people could identify eggs there are in fact well over a hundred dinosaur egg sites in the world now and places where you find dinosaur eggshell or far more abundant than that so what is an egg at least a Sheldon shell Dex appeared when vertebrates moved onto the land early reptiles laid the first hard shelled eggs before that vertebrates such as fish laid their eggs in water without any protective encasing the first terrestrial vertebrates such as this early amphibian had to return to the water to lay its eggs and like modern frogs toads and salamanders they undoubtedly had an aquatic larva stage of embryonic development in fact we might think of shelled eggs as little protective packages for early stages of embryonic development with the evolutionary invention of the hard shells the number of eggs produced went from thousands in the case of fish to one or two with some modern bird species each individual egg became more precious laying eggs on land has its advantages and disadvantages one big advantage is eggs can be hidden or protected from predators on the other hand as shelled egg requires a complex structure to function as an embryonic encasing eggs are easily damaged and cannot be allowed to dry out they need a network of pores to exchange gases with the environment and of course they need to stay within defined temperature parameters we know this from studying modern bird eggs but what about dinosaur eggs ken carpenter has written a book about dinosaur eggs dinosaur eggs are rather an interesting structure because remarkably even though they're very very old and they often have a dark color they are in fact not too different from ostrich egg with the dinosaur egg we still have a lot of the original eggshell material calcium i'm the ostrich egg and in fact almost any egg will have these very very fine pits all over them those are the pores that's how the developing embryo breeds and in fact if we look at dinosaur eggs we see the very same structure other things that we suspect is that on the inside of say this ostrich egg there is a lining of membranes that keep the yolk and whatnot from seeping out of the pores that very same membrane has actually been found in some of the fossilized egg shells from Mongolia or eggs from Mongolia so the best we can tell modern modern eggs and dinosaur eggs have an awful lot of characters that are the same so what would it take for an egg to fossilize this is a spectacularly good dinosaur egg that's the top it was very totally in this nice pretty red sandstone that's the bottom not a get fossil egg show you need special conditions eggshell will literally dissolve in most soils you bury a clutch of ostrich eggs today and your average soil and the acid in the water will slowly dissolve away the egg but not here what happened was a dinosaur laid an egg whole nest of eggs the nest was covered up with a flood layer of mud and the chemistry of the mud was slightly alkaline wasn't acid at all there was no acid in the soil water to dissolve the egg and consequently after many many layers of sediment mud and sand were piled up deep inside the forming rock the egg stayed perfect we know that bird eggs differ in size and color but what about the differences between the many species of dinosaur eggs well currently there are approximately a hundred different species of eggs this is based on different characteristics such as the egg size the egg shape the thickness of the eggshell the structure of the eggshell dinosaur eggs are laid in two basic shapes spherical and elongate the same is true for bird and reptile eggs elongated dinosaur eggs are up to three times longer than they are wide all elongated eggs identified so far are associated with the predatory raptor type theropod dinosaurs these elongate eggs can range in length from 18 inches to an inch and a half the spherical dinosaur eggs appear to be associated primarily with plant eating dinosaurs such as the gigantic long-necked sauropod and the beaked duck-billed dinosaurs these spherical eggs seem to range from four to eight inches in diameter surprisingly both the elongate eggs and the spherical eggs are not very large compared to the adult dinosaur in fact compared to birds the egg is quite often small in proportion to the adult animal the surface structure of each specimen of dinosaur egg is a major diagnostic feature here we can see the wide range of textures and patterns present on dinosaur eggs surfaces following the general pattern of contemporary hard-shelled eggs thickness of the shell is related to the size of the egg the greater the volume of material the shell needs to hold in the thicker and stronger the egg shell needs to be the shells are important in another way thin sections of eggshells when viewed under a microscope are providing defining characteristics for grouping dinosaur eggs so far beaked and sauropod dinosaur egg shell structures form one kind of pattern and the theropods formed to other kinds of eggshell patterns overall dinosaur egg study has come a long way in a short time the report of a new egg site especially one from the older Jurassic period is cause for excitement the site was discovered by dr. rod sheets rod has had a lifelong love affair with Dinosaurs rod will lead a small expedition to the unusual nesting grounds dubbed dinosaur island in the world-famous Morrison Formation joining him are Charlie McGovern a fossil preparator and dr. Robert Bakker dinosaur island is in a remote area in the Four Corners region of the American Southwest the new location has generated much excitement among paleontologists as it was one of only a handful of Jurassic sites where eggs and baby bones were found together we're finding baby dinosaurs right at the interface between the floovio over lake sediments you know but we only find the baby dry source bone right here just one note what's remarkable about this site is that 150 million years ago it was a tiny island less than 500 square feet in size it was surrounded by the waters of a river that flowed into a nearby lake the team began searching the surface of this Paleo Island for bone and egg shell fragments that weather out as a result of the summers flash rain storms today feels like a good day well it's nice if you have a breeze that you 100-plus degrees out here the team is searching for bones smaller than the tip of a finger immediately specimens start showing up on the weathered surface of the old mud stone doesn't excite you to know that a hundred and fifty million years ago mother dinosaurs were laying eggs here dr. Bacher spots a bone it's very cool what's exciting and perplexing is that the team is finding bones that represent a variety of stages of early growth from embryos to etch Ling's hatchlings that have the ability to run on their hind legs once out of the egg there's another one right guard this small site must have once been home to many chicks but just in this little pile alone here we've good there are four different sizes of animals so many baby bones this is a most unusual discovery what was happening on this little island 150 million years ago with the surface collecting completed the weathered sediment is gathered up for later screening have another bag Charlie has designed a screamin bag made out of mosquito netting that he's eager to test he wants to compare this method with the old bucket and sieve technique the discoveries at the site raise more questions than they answer how and why did the babies die why didn't they leave the nest once they were hatched the bones indicate that some of the hatchlings were two months old did they choose to stay on the island or were they trapped was this a reoccurring nesting site or maybe even a colony of nesting drier sores I don't know this is puzzling to me a lot of fun to dry a soros the guy who laid the eggs here and whose babies we find dry sores when I was a kid was one of my favorite plant eating dinosaurs because it was so flee to foot so elegant so long in the leg like a dinosaur Ian's gazelle but where I work in Wyoming it's incredibly rare to find one bone of an adult that makes your season to find eggs and embryos and hatchlings and half grown and 3/4 ground and adult all in this one tiny hell it's extraordinary demands careful thought were they living and dying and being preserved here or where predators bringing the bones the skeletons here and chewing on them or some combination there don't know yet don't know but this Hill certainly is a special place the team has moved on to the nearest river 12 miles away from dinosaur island bags and buckets are carried down to the river where the material will be processed as the water washes away of fine grains of silt and clay the remaining gravel residue reveals new bone and shell fragments and yes the compact lightweight mesh bags did work as well as the bucket and Silve method how successful was the expedition to dinosaur island I think we did pretty good so we've got several bones here we've got some vertebrae the Centrum's it's a vertebra we did it pretty good you know if we can get a handful of bones at the picking them up off the surface that's good and if we can get a handful of bones while we're at the river that's good and by the time we get all this concentrate back to the museum we wash it some more and pick through it and end up with another handful just before leaving dr. Bacher finds a specimen that may show the place of muscular attachment on an embryonic vertebrae can see little zags right there so that whole neural arch is inside that little you can see where the spinal cord went you're right there this is a significant discovery if true back in the lab the rare fossil is prepared and ultimately what the scientists hope to see for the first time was revealed holding the bones of a baby dry a sore in your hand somehow makes the world of dinosaurs a little more real so these small bones are a reminder that before dinosaurs became huge they were babies no bigger than a month-old Gosling from the fossil record we know that dinosaur eggs were laid in groups some of them in extraordinary clutches like this circle of 33 eggs laid by a theropod a meat-eating dinosaur here is a mound of spherical eggs from Argentina and another from China it's interesting to note that the spherical eggs the ones that are randomly placed in a clutch belonged to the ornithopods plant eating dinosaurs like the duck-billed and the sauropod the carefully arranged elongated eggs belonged to theropods the meat-eating dinosaurs so there are many examples of egg clutches but are they truly nests Pete Larson is the collector who excavated soon the most complete t-rex ever found Pete believes the arrangement of theropod eggs points to true nesting behavior that it is a kind of preparation for brooding birds of today which are actually very closely related to these extinct theropods birds of today will lay one egg a day or one egg every other day but theropods those extinct animals actually must have laid a complete clutch of eggs at one sitting and we see this I believe this is true because of the very careful arrangement of those eggs there's actually only a few degrees of turning and that's repeated the dinosaur would lay two eggs it would turn and lay a two eggs more it would turn again in late two eggs more until it makes this nice spiral of eggs because it would have been almost impossible for that dinosaur to go back to its nest day after day to lay another pair of eggs and have it arranged in this very specific order in this spiral arrangement now these eggs are all facing the center of the nest and there's a round vacuity around opening within that nest and then that clutch of eggs that perhaps we believe that the the mother theropod would actually be able to sit rude the eggs so there seems to be growing evidence to suggest that at least some dinosaurs like modern birds created nests to ensure the successful hatching of their young there's really great evidence these animals prepared sites for further their their nests I mean not so much from the Gobi Desert just because we don't have nest structures preserved we do have we do have eggs that are found in typical positions to seem to be uniform for particular species like the over up towards for example always lay their eggs with the long axis facing out from the nest rather flat Rodan's on the other hand lay their eggs sticking straight up so these are stereotypical four species at other parts in the world however people have really found things which I think that we can't interpret his nest structures for that there are places that have been hollowed out in the ground where the eggs are deposited and all of this suggests that the nesting that we see in modern birds when they build nests in the nesting that we see in modern crocodiles when they build nests is something was present in their common ancestor and we would also expect that to be found in dinosaurs which are descended from that common ancestor but a former American Museum colleague of mark Norell dr. Lewis Chiaki made a momentous discovery while leading an expedition to a remote region of Patagonia that would forever change how we view dinosaurs well we found this place which is a fantastic site in 1997 we were actually looking for very different stuff we were looking for the ancestors of birds and early birds and then we would discover this flat area where essentially the ground was leader with eggshells and when we did a little bit more of reconnaissance of the whole area we realized that we had found this enormous dinosaur nesting site extending over miles and miles clearly the largest dinosaur nesting site ever found how large was the site it may eventually prove to be over 15 miles long with hundreds of thousands of eggs not only that the egg layers are repeating we have at least four different egg layers in the stratigraphic section of the site which means that dinosaurs the dinosaurs return to the site time after time sorry behavior we call site fidelity each of these four distinct fossil egg deposits represents a nesting season when the eggs were destroyed by a flood event here was proof for the first time that dinosaurs in fact huge sauropod dinosaurs that lived 80 million years ago called titanosaurs exhibited nesting behavior like alligators and many birds were turning over and over to the same nesting site once a dinosaur egg hatched what happened where the chicks altricial helpless like many birds are today or were they capable of moving from the nest immediately precocial like the South American Rhea in any case did a family structure form for the care and protection of the young for most modern reptiles and crocodilians once the eggs are laid success of the hatchlings is determined by luck and large numbers in this clutch from the previous year only one hatchling has survived and finally did some dinosaurs form long-term family bonds such as those exhibited in a dolphin pod a short time ago it seemed these questions might have to remain unanswered but some new and exciting fossil discoveries have opened the door to peer into the past while dinosaur egg finds were becoming common the hope was to one day find a baby still inside the egg such a specimen could answer a lot of questions at the end of the 1970s hatchling or embryonic bones still inside the eggs were found in the Badlands of Western North America the first was the Cretaceous Mya Soros found by Jack Horner in eastern Montana but soon after Phil Curry's team found duck billed embryos in Alberta as well we went out in the mid-1980s and we found an excellent egg site where we had in fact duck-billed dinosaurs still as embryos inside of the eggs from the early discoveries of embryonic and hatchling bones a picture was emerging at least in the case of the Maiasaura and the large plant-eating duckville dinosaur the babies were essentially miniature versions of the adults the difference between embryonic and juvenile bone as far as duck-billed dinosaurs or hadrosaurs our concern is mainly the size if we look at an embryonic bone and a juvenile bone of the same species there's not a lot of difference in the features seen in these two bones you do see different this is a limb bone main difference between the embryonic and juvenile lower jawbone is that the embryo has a lot less teeth obviously as the animal got older it had to add teeth so it could consume more food soon other embryonic bones were found such as this embryonic Protoceratops one of the beaked dinosaurs and remember that enormous sauropod nesting colony in Patagonia not only were embryonic bone and skulls found in the eggs but something unexpected among the many firsts that we came up when we found displays and over the years of research we've done then there is the discovery of the first embryonic dinosaur skin this is the only site in the Cepeda ganya side the only site in the world where you can go walk around for a little bit maybe an hour or so and come back with a piece of dinosaur baby dinosaur skin they're quite abundant embryos are quite abundant as part of the the carnage that you know happened when the flood flooded the whole area but and it is of course as any scientific first interesting for the first time we can flesh out the babies and learn how they look like I mean we know that the skin has a scaly aspect we can see different patterns of the tubercles or the scales or the knobby texture that essentially line the body of the of the baby sauropod for example some of them form rosettes some of others form flower like patterns were there little scales that have the shape the triangular shape of a petal and then you see long stripes of larger scales that cross a uniform field of of smaller scales presumably those that those rows run across the back of the baby so far it is difficult to place the skin precisely over the skeletons of the babies but specimens showing this may be forthcoming in an interesting way the quality of bones and skin inside an egg is one step better than the bone and eggshell associations found at dinosaur island what if we could have a snapshot a moment of living dinosaur behavior captured complete frozen in the fossil record for all time it turns out such an event is possible in the 1970s a polish expedition into the Gobi Desert of China unearthed this remarkable fossil it is called the fighting dinosaurs besides the extraordinary preservation of the Protoceratops and the velociraptor the fossil has captured the behavior they were engaged in right up to the moment of their death here's how it might have happened locked in a life-and-death struggle these two creatures were buried alive such extraordinary fossils are called life assemblages a fossil records can be divided into two categories one is called death assemblages where animals die they're ripped apart by predators and things like that then all their bones are washed into a deposit on the other hand there's life assemblages where animals are buried alive and it's really the life assemblages which I think tell us the most about parental care so the search was on to find fossils that would reveal the secrets of dinosaur reproductive and social behavior and the place to look was the Gobi Desert remember the Gobi Desert in Mongolia was where Roy Chapman Andrews led his groundbreaking expedition in the 1920s it was the place where dinosaur eggs were first properly identified but it was also dinosaur heaven for paleontologists because of the abundance of dinosaur remains and their exceptional state of preservation for decades paleontologists had wanted to return but the political unrest in China had made that impossible gradually Chinese restrictions lifted and Western dinosaur hunters once again set their sights on the Gobi first came communist bloc paleontologists and in the 1990s Americans and Canadians were picking up where Chapman Andrews had left off the flaming cliffs area contains some of the world's richest dinosaur fossil beds it is of the Late Cretaceous age in the seventy million year range as the fossils have been uncovered they have revealed a virtual picture book of dinosaur behavior in 1993 a team of paleontologists from the American Museum led by mark Norell began to unearth an extraordinary Oviraptor specimen in the Gobi Desert an Oviraptor is a medium-sized bipedal dinosaur it has powerful long claws and oddly no teeth its name means egg Robert because specimens were found in association with broken eggs the belief was that it had stolen and eaten the eggs but was that assumption ever wrong when they finished uncovering the Gobi Desert specimen the team made an exciting discovery well starting in 1993 we discovered some great Oviraptor fossils in the Gobi Desert these are great because if they're actually snapshots of time it's an animal sitting on top of its nest brooding its eggs just like a modern bird would some people have questioned our interpretation of it saying that in fact this animal either died in this position haphazardly associated with the nest or it was in the act of laying eggs I think we can really disqualify that on a number of grounds one of the major ones is we found other individuals now we've found two more at the same locality in the Gobi Desert there's one that was founded by an Monda who in China all of these animals have the same stereotypical position of sitting in the middle of the nest with their arms wrap back around the perimeter of the nest so just because we always find them in the same position really indicates to me in fact that they were brooding their eggs in the same way that modern birds do today an Oviraptor probably looked very much like this crane as it sat on it smashed and since these dinosaurs were actually brooding their eggs it would mean that at least some dinosaurs were warm-blooded imparting heat to their eggs now if we could only get a snapshot of a dinosaur chick freshly hatched from an egg we might be able to tell how much parental care was required for these infant creatures were there in fact any dinosaurs that were altricial needing intense parental care to survive this is a behavior exhibited by many bird species or were all dinosaurs precocial able to run freely once out of the egg without knowing dinosaur growth rates it would be hard to say if any dinosaurs were all trishal what paleontologists really needed was to find babies that had just hatched perhaps they were in luck about the same time as the egg sitting over Raptors were found another extraordinary fossil life assemblage was uncovered in the Gobi Desert prepared and studied at the Hayashi Barra Museum of Natural History in Japan but now back in Mongolia this specimen shows a flock of baby Protoceratops all of the same age clustered together as if in a nest without a doubt these animals were living together these 15 individuals probably formed a social group but what kind of social group were they like this alligator nest with a nearby mother performing a protective function and the nest representing a mere grouping rather than a sophisticated social bond between the babies maybe they were part of a rapidly moving family group like these geese with complex social bonds or were they confined to a nest requiring true parental care in other words is this a nest of helpless babies further work on the bones from this specimen might enable paleontologists to conclude which of the three possibilities is actually the case to find out if any dinosaurs actually performed complex caring for their young we would need to find an adult caught in the act of feeding its baby or find a chick that had just hatched from an egg Whois bone structure showed that it was incapable of moving around besides marking the return of paleontologists to the Gobi the 90s was also the decade of dinosaur egg discoveries thousands of dinosaur eggs poured out of China into museums and private collections one such specimen arrived in the United States from Hunan China in 1993 often these specimens needed elaborate preparation to reveal the eggs and nests hidden in their matrix as preparator Charlie McGovern began the tedious process of removing the rock covering the nest to his surprise he found dinosaur bones in fact baby dinosaur bones in time Charlie uncovered a complete skeleton of a hatchling dinosaur and dubbed it baby Louie could this be the baby dinosaur scientists had been looking for the presumed sequence of events leading up to the preservation of this exciting fossil probably went like this the eggs were laid in the typical circular shape of most Raptor dinosaurs the mother or father incubated the eggs up to the time of hatching you you baby Louise escaped from the egg evidently proceeded normally but shortly after something went wrong just a few inches from the egg baby Louie died and almost instantaneously was covered with sediment what we have here is a very unique specimen from China it's a group of dinosaur eggs with an embryo or baby dinosaur lying on top this is an animal that died during the hatching process or shortly thereafter this specimen represents a new unknown giant species of over after careful bone histological study of Baby Louie hopefully will reveal if it was precocial or all trishul the evidence to date points to it being more all trishal than most dinosaur babies found so far perhaps crane like nearly all of the dinosaur bones found in North America do not fit the life assemblage criterion this is called Jurassic hernia paleontology oh love it well done this is a back bone there so flex knee there another need there but in the first year of the new millennium dr. Bacher made a startling discovery in his coma bluff flying dinosaur quarry he found a specimen that may indeed qualify as a life assemblage in fact he thinks it might be a nest in the form of a burl rather than excavate the individual skeletons in the field he dug out and brought the whole burrow back in a plaster of Paris jacket to be cat scanned at the Avista Hospital in Colorado the hospital staff was excited by the prospect of having a 141 million year old group of patients the dinosaurs inside the small Burrow were a small plant-eating species called Drinker about the size of a large house cat they would have been on the low end of the food chain a tasty meal like ground squirrels or prairie dogs today for almost all the larger meat-eating dinosaurs of their time so they probably used burrowing for hiding and protection the cats can work know one by one individual eyes were revealed the little drinkers appeared to be compressed together almost one on top of the other we've already discovered three individuals I didn't know where they were there though in between the top layer in the bottom layer the picture that was emerging was a surprise that's the fourth dinosaur we've seen coming through like that yeah we probably have only gone through a third of it mineralized that means this was precocious when the guys had cheated not only were they finding babies but adults and juveniles as well but this knee belongs to somebody else that's too small to go with this tale this is an adult tale and this is about a heavy inside the Burrow was an entire large family group much like a prairie dog colony today with young and old living together at the end of the day 12 individuals of varying sizes were revealed all lined up facing west in a curiously calm posture almost as if they died in their sleep without a struggle more rotate me oh now you seem that side view of the vertebral bodies in the tail yep so this is indeed a life assemblage perhaps they died from a disease as today often sweeps through prairie dog colonies but was this life assemblage a nest probably not since no eggshell was found unless of course the drinkers gave birth to live young a phenomenon currently present in some snakes but not birds with just these four spectacular snapshots in time paleontologists have garnered more accurate information about dinosaur reproduction than in the past 150 years of collecting and study combined you since the first fossil bird the now-famous Archaeopteryx was found in the 19th century in Germany speculation has centered on the idea that birds are living dinosaurs so what do the eggs of dinosaurs tell us about their relationship to birds when you look at dinosaur eggs you see there's a tremendous variety not only in the the shapes of the eggs and the textures of the eggs but also the histology the the microscopic structure the eggshell itself is quite different in different groups of dinosaurs one thing is quite clear though that when you compare the eggshells of dinosaurs to the eggshells of modern animals they're much closer to what we see in birds than they are what we see normally in crocodiles and especially the eggs of the meat-eating dinosaurs which in many ways are almost indistinguishable from bird eggs work on dinosaur eggs and baby dinosaurs has been rather revealing as far as understanding dinosaur relationships for example if we take this ostrich egg and we look at cut a section of it make it so thin that we can see through it with a microscope we will see that the structure the eggshell is in fact very very similar to the eggs of many dinosaurs that's rather interesting because if we then also do the same thing with a crocodile egg the egg structure is very very very different and everything we know about dinosaur eggs and hatching sites and dinosaur bones and tracks prove this same message when you think dinosaur think big bird so birds and theropod dinosaurs are basically the same creatures with a common ancestor that would be another dinosaur not a reptile a crocodile more and more scientists are saying birds are living dinosaurs what remains is to discover more dinosaur nests more dinosaur babies and more dinosaur life assemblages just when we feel we understand them dinosaurs reveal another clue and another and another from their cryptic legacy perhaps they will always keep us guessing but it is certain they will always keep us in wonder you

Channel: Janson Media

Views: 1,777,884

Rating: 4.4058561 out of 5

Keywords: Dinosaurs, Historic, Pre-Historic, Dino, Robert Bakker, Philip Currie, Mark Norell, Animals, Eggs, Nests, Babies, Mysteries, Documentaries, Educational, Dinosaur, T-Rex, Reptile, dinosaur eggs, dinosaurs eggs, dinosaur program, baby eggs

Id: uChHLNTOmZI

Length: 57min 10sec (3430 seconds)

Published: Wed May 13 2009

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