|
David Attenborough's Natural History Museum Alive (2014)
The Natural History Museum.
One of the most popular of all London's attractions. Sometimes it gets so crowded that it can be quite difficult to see the exhibits as closely as you might wish. Ladies and gentlemen, the museum is going to be closing in five minutes, so please make your way towards the exits. Thank you. So it's a great treat if - somehow or other - you can manage to look around when all the other visitors have gone. Some of the creatures here you might - if you were lucky - have seen in the wild. But there are certain ancient animals that we'll never see with our own eyes... ...because they're extinct. And among them are one or two mysterious, not to say suspicious, characters that I would like to examine as they were when they were alive. 'It's a big place. 'There are 70 million or so specimens here, I'm told. 'And the first I want to look at right now 'is way up on the very top floor.' This, some might say, is the most scientifically important and valuable specimen in the whole of the museum. It's a fossil called Archaeopteryx and it was secured for the museum by the first director, Professor Richard Owen, back in 1862. Getting it wasn't easy. There was a lot of international competition and there was a certain amount of skulduggery and it certainly cost a small fortune. But what kind of creature was Archaeopteryx when it was alive? It had two long leg bones, so it must have stood upright. A bony tail and a long neck. Its head had bony jaws packed with teeth like a reptile's and its arms had three elongated fingers, each ending with a claw. So, you might think it was some kind of strange, spindly-armed, upright-standing lizard. Except for one fact... There is evidence of more than just bones on its slab. Feathers. Archaeopteryx lived some 150 million years ago, long before the appearance of true birds. Those feathers on its arms certainly enabled it to glide. But that's not all. It had powered flight. Marks on the bones show that there were enough muscles attached to them to enable it to flap. Not only that, a recent scan of its skull showed that its brain would've given it the senses and reactions that are needed for accurate control in the air. This creature was half reptile, half bird. It was the first proof that, in prehistory, they were intermediate forms that link the big, very different groups of animals that we know today. But while Archaeopteryx could certainly fly, it could also clamber up tree trunks and along the branches like a tree-living reptile, thanks to those clawed fingers. There were insects flying around at that time. And Archaeopteryx's teeth show that it was a hunter. And this is Professor Richard Owen, the man who acquired that fossil and built this museum. Although he disagreed with Darwin's views on evolution, he was one of the great scientists of his time and he had a particular flair for interpreting fossils. In 1839, a huge thigh bone was sent to the museum from New Zealand. Owen deduced from its internal structure that it must have belonged to a bird. If so, it must've been a giant. The Maoris of New Zealand had stories of giant, flightless birds that had once roamed their islands, but Europeans had dismissed them as myths. But eventually, Professor Owen acquired enough bones of these huge birds to put together a complete skeleton of one of them. This was no myth. The Maoris in their legend had called it a moa and Professor Owen in his researches had proved that it once had existed. But was it the largest bird that had ever lived? There were several different species of moa, but this one was the biggest. It stands 3m tall. But is this really what it looked like when it was alive? You can tell how an animal holds its head from the junction between the skull and its neck. If that is underneath the skull, then its neck would have been upright. But this moa's neck joint is at the back of the skull, so it must have held its neck more horizontally, like this. So was the giant moa the biggest bird that has ever existed? Well, if it craned up its neck, it was almost certainly the tallest. You might think that such a gigantic bird would have no enemies in the remote and isolated forests of New Zealand. Well, there's also a Maori legend of a huge predatory bird, an eagle, that existed at the same time. And what is more, there are bones to prove it. This colossal bird was nearly twice as heavy as today's most powerful eagle. Bringing down a giant moa must have been a huge task. They, too, were strong and heavy. But the eagle had powerful eyesight... ...a beak the size of a butcher's cleaver... ...and razor sharp talons as big as the claws of a tiger. The Greek for grappling hooks is "harpax". And that word gives this bird its name. This is Harpagornis. It was a deadly predator. It was the largest eagle that has ever existed. And it lived in the same forests as the moas. We know that Harpagornis preyed on moas because moa skeletons have been found with holes stabbed through their pelvic bones that exactly match the grasp of the eagles' claws. It was probably even strong enough to cling to a moa's back with one foot while it slashed at its victim's neck with the other. But it looks as if this moa is going to escape - for now. As well as its millions of specimens of animals and plants, the museum also has huge and fascinating archives, scientific journals from all over the world, letters from explorers, even posters and handbills if they have anything to do with natural history. In the 19th century, when Professor Owen was in charge of this museum, new and extraordinary things were turning up from all over the world and Professor Owen was very keen that his museum should have the best of them. He secured the Archaeopteryx from Germany, the moas from New Zealand, but sometimes, really strange things turned up on his very doorstep. And there were certainly lots of very odd creatures being exhibited around London in Victorian times. This print shows an extraordinary monster that was being displayed in Piccadilly. An American showman called Albert Koch was charging a shilling a head to have a look at it. Professor Owen decided to investigate. He felt sure that something was wrong with it, but nonetheless, he was intrigued, and he bought it. When he'd got it back to his museum, he was able to examine it in detail. It was certainly gigantic and bigger than anything else he had in his museum at the time. Koch, the showman, had dug up the bones from a farmer's field in Missouri and maintained that in life, the animal had stood 9 meters long and almost 5 meters tall. There were claims that this was a fearsome predator, that used its extraordinary tusks for stabbing its victims, presumably by swinging its head sideways. Well, I'm sure Professor Owen would've had something to say about that. He must have realised that these blunt, rounded ridges on these huge molar teeth would be very effective at grinding up twigs and fir cones and rough forest vegetation, but they lack the sharp blade that you need to slice through flesh. This is not the jaw of a carnivore. It soon became clear that Koch had increased the size of his monster skeleton by adding extra vertebrae, ribs and even blocks of wood. The Missouri Leviathan was a fraud. So Owen removed all the extra bits. And then he put the real bones back together in their true form. Finally, he detached those astonishing tusks and put them back in the correct way. It seems obvious now, but in life, they had pointed in much the same direction as those of a modern elephant. And so, here today stands not Koch's leviathan but Owen's mastodont a vegetarian relative of the elephant that lived 12,000 years ago in North and Central America. It may have decreased a bit in size, but it's still an astonishing animal. Our understanding of the mastodon is a lot more accurate today, thanks to Professor Owen. But it was not the only creature in this museum to be the victim of misrepresentation. This poor old bird is a dodo. It once lived on the island of Mauritius in the Indian Ocean and it's almost certainly the first animal species that human beings actually exterminated in historic times. And so now we talk about being "as dead as a dodo." But in spite of its fame, this one is a fake. Its feathers come from a goose, its feet were modelled on a turkey and its beak, I suspect, is plaster. The museum can be forgiven because no skin or feathers of the dodo survive. Its image was influenced by pictures like this one, painted by a 17th century Dutch artist, Roelandt Savery, but he had never seen a living dodo and based his image on accounts by seafarers. I've often wondered whether dodos actually looked like that, but unfortunately, they'd all disappeared before anyone could get a good look at them... ...until now. This funny, dumpy creature is how the bird is usually represented these days. But I've seen quite a lot of flightless birds over the years and this one doesn't quite ring true. An examination of the way its thighs join its pelvis has shown that, in life, it actually stood much more upright. We now know that its feathers were probably a lot fluffier than in that painting. We also now know that it was related to the pigeon and some experts suggest that it made a pigeon-like call - "Doo-doo, doo-doo" - which gave the bird its name. The dodo probably fed on fruit - there's a lot of it on the island. I'll try him with a bit. Come on. What do you make of that? Ow! That's a very powerful beak. In fact, it may well have been adapted for crushing shells and crustaceans for the sake of the calcium. 'And there's a female.' Maybe she is another reason why they had such large beaks - to show off with during courtship. And here comes a rival male. He could be another reason for having a huge beak - to fight with in disputes over nest sites. Until now, no-one has ever seen a dodo egg, so no-one knows how big it was. But after tonight, who knows? Science has revealed the truth behind many a myth and discovered some creatures that are so odd as to be scarcely believable. But there is one story that is still remarkably persistent. Back in 1951, a famous Himalayan explorer and mountaineer, Eric Shipton, came across some footprints across a high snowfield that looked as if they'd been made by some kind of giant ape. Shipton's Sherpa companions had no doubt about what had made them. A yeti - an abominable snowman. Well, there is one small, insignificant-looking specimen in the storage vaults down here that could, perhaps, explain those prints. It was found in a shop in Hong Kong that sold Chinese traditional medicines. It was the molar tooth of some kind of ape-like creature, except that it was huge. The museum has only got a fragment, this is it. But here's a cast of a complete one and it's six times the size of one of ours. It was given the name Gigantopithecus - "giant ape." After that discovery, one or two more teeth were discovered, but nothing much, until eventually, a piece of the lower jaw was found. The original is now in America, this is a cast, but here is the lower jaw. If this animal had a skull the same proportions as those of a gorilla, its complete skull would've been this big. This was a true monster. So we know a huge ape did exist, Gigantopithecus. It could well have stood 3m tall, in which case, it would've been eight times as heavy as I am. And if you're as heavy as that, you don't spend much time climbing in trees because they won't support you. So the likelihood is that his arms are quite short and he walked upright. He was bipedal. I'll get out of the way. An upright animal has its head on the top of its spine, as I do. And if that head is to be well-balanced, it's better not to have a long muzzle, but a rather flat face. So if I were to observe Gigantopithecus and it stared back at me, I suspect I'd find its look rather unnervingly familiar. Gigantopithecus is commonly thought to have died out several hundred thousand years ago. But sightings of the yeti continue to be reported, so is it possible that some kind of giant ape, maybe even Gigantopithecus itself, still survives somewhere out in those remote Himalayan mountains? The Gigantopithecus tooth isn't the only intriguing specimen down here in the storerooms. This - a piece of dung. Looking at it, you might think it had dropped to the ground only yesterday. 'It was found in a cave in Patagonia.' And with it, a piece of skin, like this - covered in a very coarse, bristly hair and on the underside, mysterious white bone nodules, as though it was a kind of armour. No known creature alive today has armoured hide like this. If it still survived, it would be a truly extraordinary discovery, so at the end of the 19th century, explorers and scientists started a search for it. In fact, the dung and the fur appeared to be recent only because they had been, in effect, freeze-dried in that ancient cave. The creatures themselves had died out some 10,000 years ago. But explorers did find their skeletons. They were giant sloths that lived not in trees, as modern ones do, but on the ground. And this one had immense claws. What could it have used them for? These giant sloths probably spent most of their time on all fours but nonetheless, they were perfectly capable of rearing up on their hind legs. And when they did that, they probably stood about 3m tall, which was as tall as a grizzly bear, if not taller. But I don't think this one is going to use its claws on me. That dung made it clear that these creatures are vegetarians, so they doubtless used those claws for ripping up plants. But it's been discovered recently that they used them for something else as well. Something that seems rather surprising for animals of their great bulk. They dug burrows. Huge excavations like this have been found all over Patagonia and we know they were made by giant sloths because scratches on the walls of the burrows exactly match their claws. Such immense burrows must have been excellent places to take refuge. And the giant sloths may well have had need of them because there was a truly ferocious predator living alongside them. A great cat with immense sabre-shaped teeth. Smilodon. For me, there is no more alarming animal in the whole museum than this. And its skeleton is perfectly preserved, because about 10,000 years ago, it wandered into a pool of naturally occurring tar, oozing from the ground in California. In general shape, it was somewhat like a lion, but more muscular and much heavier and those sabre teeth were really sharp. No wonder the giant sloths needed burrows in which to take refuge. You might think that Smilodon would have caught its prey as a lion often does, by chasing it, leaping on it at speed and then throttling it, suffocating it with a bite to the neck. But Smilodon stalked its prey, creeping quietly across the plains until it got really close. And then, it pounced! Smilodon couldn't throttle its prey with those huge teeth and they were too brittle to slash. They would shatter if they struck bone. Instead, the animal would have first used its great weight to pin down its victim. Then it would have used its sabres like blades to slice open the soft flesh of its victim's throat. But these terrifying hunters had a rather touching side to their characters. Tigers today are solitary hunters and when one gets too old to hunt successfully, it dies. But skeletons of really elderly sabre-tooths have been discovered, which suggests that not only did Smilodon hunt in packs, but when members of the family were too old to hunt for themselves, they were allowed to take a share of the kill. The museum is full of creatures that appear terrifying, but which no doubt if you knew them better, would prove to have quite a charming side to their characters. But there is one here that would, I think, chill everyone's blood. This is a vertebra from the backbone of a modern snake. It was a python and we know exactly how long it was because it was measured when it was alive. It was 21 feet long, 7meters. This, however, is a similar bone from the spine of a fossil snake and if this was 20 feet long, how big was this? Certainly 30 feet, 10 meter, 11 meter. It was a monster. But what did it live on in those far distant times? Maybe if I follow it, I'll find out what it ate. Science calls this snake Gigantophis and it was truly immense. Certainly big enough to swallow me. But would it have eaten human beings? It might well have done if we had both been around at the same time, but it lived 40 million years ago and had become extinct long before human beings appeared on Earth. So maybe it preyed on dinosaurs. Well, no. Dinosaurs are even older than Gigantophis and disappeared some 25 million years before it evolved. In that case, what about mammals, such as sheep or deer? No - at least not modern mammals like these. The early mammals were rather different from the kinds we know today. This is a model of a prehistoric elephant that was unlucky enough to wander about the planet at exactly the same time as Gigantophis, about 40 million years ago. But how could Gigantophis tackle one of these? Well, he didn't use venom to kill its prey. We know from its massive size that it must have been a constrictor. Constrictors, having seized an animal with their jaws, wrap their coils around their prey and squeeze so hard they stop their victim's heart and it dies within a few minutes. I wonder if he realises that his dinner tonight is a fibreglass model. I'll leave him to it. There are specimens of animals here from every corner of the Earth. But it was much closer to home, on the south coast in Dorset, that a group of amateur Victorian fossil hunters discovered these amazing fossilised creatures. But what kind of animals were they? They clearly lived in the sea because seashells are found alongside them in the rocks. They had bony paddles - not fins, like fish - and huge eyes, protected by a ring of plates. Those Victorian pioneer scientists, led by Professor Richard Owen, worked out that they were too old to be mammals and were certainly not fish. They were reptiles. Owen and his friends called them ichthyosaurs - "fish lizards." Now it's got skin and flesh on it, you can see how remarkably similar it is to today's dolphin. It's got the same streamlined silhouettes, same pointed jaws, it's air breathing, even gives birth to live young. But surely an ancient ichthyosaur couldn't be as advanced as a modern-day dolphin? Or could it? Dolphins are mammals. Ichthyosaurs, reptiles. Very, very different groups. They're not at all closely related and yet, they both have very similar body shapes. They're a remarkable example of what's called convergent evolution - two groups of unrelated animals that have evolved similar bodies to suit the same environment. But there ARE some differences. Dolphins beat their tails up and down like their cousins, the whales. Ichthyosaurs, as is clear from their fossils, had tails like fish that beat from side to side and dolphins only have two flippers, whereas ichthyosaurs had four. So is it possible that ichthyosaurs were as fast in the water and as agile as dolphins, if not more so? I wonder who would win in a competition. One kind of dolphin - spinners - can leap from the surface of the water and spin in the air. Maybe the ichthyosaurs could do the same. We know that ichthyosaurs lived and evolved on this planet for many millions of years more than dolphins have done so far, so maybe ichthyosaurs would have won the competition after all. Who knows? While the ichthyosaurs and other marine reptiles ruled the seas 150 million years ago, another group of reptiles dominated the land. They lived long before big mammals, let alone human beings. There are hundreds, probably thousands of different kinds, and they came in all shapes and sizes. They are perhaps the most famous and dramatic of all prehistoric creatures. And they were first identified and named here in Britain. They were the dinosaurs. Thousands of people come here every day to look at their amazing skeletons and to imagine what they must have looked like and sounded like when they were alive. It's hard to imagine a time when the world didn't know about dinosaurs, but until relatively recently, nobody knew they had ever existed, let alone that they once ruled the world. The story of their discovery starts in the 1820s when a doctor named Gideon Mantell living on the south coast of England in Sussex picked up something odd in a sandstone quarry. And this is what he found. It's clearly a tooth of some kind. This is its outer surface and in shape, it's very like the tooth of a living lizard, such as an iguana, which is why the animal it belonged to came to be called lguanodon - iguana tooth. And with it were a number of other bones. They were the hips and back legs of some kind of giant reptile. More of them were discovered and soon, there were enough to get some idea of what the whole animal had looked like. One odd little bone seemed to have nowhere to go, so the reconstructors put it on the end of its nose, making the animal look like some kind of reptilian rhinoceros. It was like nothing anyone had ever seen before. So a great fossil hunt started in the quarries of Sussex. And eventually, the bones of several different kinds of big animals were discovered. They were brought here to the museum. Professor Owen examined them and he decided that they should belong to a completely new kind of animal, an animal he called a dinosaur - "terrible lizard." In due course, more complete skeletons of Iguanodons were discovered and it became possible to reconstruct them with greater certainty. Iguanodon could stand upright. It had small arms and was over 25 feet 7meters tall. And that horn on its nose was actually a spike on its thumb. Before long, new and even bigger species were being unearthed all over the world, from the instantly recognisable three-horned Triceratops to the sensational Tyrannosaurus rex. These astounding beasts have inspired and captivated not only scientists, but writers, artists and filmmakers for almost two centuries. But it was Professor Owen, here in the Natural History Museum, who first identified them. And his work has been continued here ever since. This is the laboratory where the museum prepares its fossils for study and for display. It's here that they painstakingly remove the excess rock to reveal the fossils in all their extraordinary detail. This is the fossilised egg of a dinosaur, one of the first to be discovered, and it was found close to some bones of a sauropod dinosaur. Sauropods - this is a model of one - were gigantic vegetarian dinosaurs that wandered around on four legs. There are lots of different species of them, they're found all over the world, and they're the biggest land animals that have ever existed. Of course, you can't prove that it was a sauropod that laid this egg. But I would like to think that it was. The weight of the sand that eventually covered it squashed it, but if we could see it when it was first laid... ...we would see that it's much rounder than a chicken's egg, more like that of a turtle or a crocodile, and of course, very much bigger. Sounds like something's in there. But how will that something make its way out? Most dinosaur eggs are shell filled with rock, but not so long ago, someone in South America found a sauropod egg, and inside, there was a baby sauropod. On its nose, it had a little egg tooth. Birds and crocodiles have the same sort of thing. They need it, as the sauropod did, in order to be able to break out of the shell. Oh. We know that baby sauropods were very small and left their nests very early, perhaps to avoid being trampled upon by their huge mothers. They probably hid in the forest until they grew large enough to join the herd of adults. Hello. Well, this is just one leg bone of a fully grown sauropod, so you can see this little fellow has got quite a lot of growing to do over the next few years. The museum, of course, has the skeleton of a fully grown sauropod - of a kind. And its story is one of kings and millionaires. Back in 1902, King Edward VII, then Prince of Wales, saw a picture of a huge sauropod replica, one of the biggest yet discovered, while visiting the Scotsman turned American millionaire Andrew Carnegie at his castle in Scotland. The prince immediately said, "Well, I would like one of those," and in those days, what princes asked for, they got. And so, in due course, another replica turned up right here in the Natural History Museum. And there it is. There are two ways of pronouncing its scientific name. It's either "DIP-lo-DOH-cus" or "dip-LOD-ocus". Either way, it's a bit of a mouthful, so I'm going to use the nickname that is commonly used around here. This is Dippy, and what's more, although there's no way of being sure whether it was male or female, I'm going to assume that Dippy was female. But what did Dippy look like when she was alive? This strangely-shaped fragment of a dinosaur called Edmontosaurus was mummified before it was fossilised, so not only the bones but the skin was almost perfectly preserved, and it was covered in small scales. They didn't overlap like those of a lizard, but formed a close-fitting mosaic. Maybe Dippy was like that too. But what about her colour? My suspicion is that Dippy, like many large mammals today, such as elephants or rhinoceros, was a general all-over neutral plain colour, so if we add a little bit of skin and flesh, we can get some idea of what she actually looked like. So now, after 150 million years, we've got a pretty good idea of what Dippy looked like. But how did she behave? Well, animals her size and weight must have moved in a rather ponderous way. And in any case, since she was a vegetarian, as we know from her teeth, she had no need to be speedy to get her food. But it's the tiny bones in Dippy's inner ear that can give us a clue as to what she sounded like. These little bones are basically the same shape as that of the dinosaur's closest relatives, birds. The range of sounds a bird hears is related to its size. A small bird makes and hears high-pitched sounds, whereas large birds can communicate with low-pitched sounds. So huge Dippy, with her inner ear bone shaped like those of a bird, could probably hear very low-pitched frequencies of sound. And she could probably make them, too. We know that elephants today can communicate using infrasound - sound with frequencies so low they're below human hearing and those sounds travel through the ground, sometimes for many miles, and are detected by elephants through their large, flat, sensitive feet. Dippy, too, had large, flat, feet. So maybe the giant dinosaurs communicated with one another in much the same way, as well as by bellowing. And those may not have been the only noises that Dippy could make. Some scientists think that because of the length of her tail, and the way the joints work, she must have been able to crack it like a whip. The muscular strength that enabled her to hold her tail above the ground meant that she could, if necessary, use it as a weapon. Her tail would have helped to balance her long, heavy neck, but why was that so long? It used to be thought that she lived in rivers and needed her neck to break the surface in order to breathe But that can't have been true, because if her body was submerged, the pressure of the water would have crushed her lungs. The most likely explanation seems to be that her huge neck helped her reach vast quantities of leaves. Sweeping it from side to side, she could cover a larger grazing area. She could also push her head between forest trees to reach ferns and other ground vegetation. In order to reach the highest, most succulent leaves in the forest, it seems likely that Dippy would have reared up on her hind legs. Come on, Dippy. Breakfast. Come on. Oh, hello. London's Natural History Museum is full of wonders. It's a place where we can get a vivid idea of the great variety of life that inhabits our planet, both today and in the past, especially after a night like that. |
|