"Most fossils are just the hard bits that nature leaves behind." "Cells, like these." "The other parts of the organism, the soft parts if you like - feathers, guts, and many kinds of organisms that are soft-bodied, leave no trace behind." "Except in a few very special places." "And it is to these places that we are going to travel in search of windows into the past." "So far in the series, we've been 8,000 feet up in the Rocky Mountains of Canada to discover the fossilised remains of the earliest complex life." "While, in the heart of Europe, we'll explore a long-lost lake that has preserved some of the best fossils of early mammals ever uncovered - including, perhaps, our own earliest known ancestor." "Now, in this second episode, we're travelling to a site in Northern China to investigate some of the most surprising dinosaur fossils ever discovered." "It used to be thought that the dinosaurs died out in a cataclysm 65 million years ago." "'But, now, we know different.'" "What is going on here?" "Right, yeah, yeah." "This is a dinosaur egg." "Dating back to 160 million years ago, the discovery of fossil feathers in China has revolutionised our understanding of what happened to the dinosaurs." "Evidence now shows they evolved into all sorts of unexpected and exotic species." "Including the ancestors of the birds." "I'm taking my own personal voyage of discovery to uncover the story of how birds evolved." "Joining me is Lisa Morgan, a warden for the RSPB." "After nearly an hour, we reach our destination, Grassholm Island - a jagged and inaccessible hunk of rock jutting out of the Irish Sea." "It's home to more than 66,000 of the largest and heaviest sea bird in the North Atlantic, the gannet." "Well, from a distance, of course, this looked like a snow-capped peak." "It does indeed." "And, you get nearer and you see it is, well, thousands upon thousands of gannets." "Is that the old thing about safety in numbers?" "Well, I don't know that it really is with gannets." "Nothing really is going to worry them - they've got that huge, pointy bill and they're very aggressive birds." "So, really they just need an isolated place to breed - ideally with no land predators, very important." "And, also, they need lots of breeze." "So, these are big heavy birds, weighing three kilos." "That's to take off?" "Yeah, exactly that." "So, on a calm day, they really use a lot of energy to get off the ground." "Well, let's talk a little about, bit about adaptation." "They're obviously superb aeronauts." "They are." "They've got long, narrow wings, so they can really take advantage of the wind, so they can move very efficiently through the air." "But also they plunge dive from quite a height actually, maybe ten, 20, 30 metres above the water." "And, when they do that, they bring their wings right back behind them to avoid stress on the wings." "They turn into some sort of torpedo, briefly." "It's an amazing thing to see." "It's an extraordinary thought, that this exquisitely adapted and elegant bird is descended from a creature that many people think as rather cumbrous - the dinosaur." "And it is that story that we will be exploring in this episode." "Today, there are more than 10,000 species of birds." "They have mastered the air, the land and the world's waters." "Some, like the gannet, have even adapted to all three at once." "But who were their evolutionary forebears?" "A country that has yielded surprising discoveries that are revealing new answers is China." "One of the great revelations greeting a westerner arriving in Tiananmen Square today is the sheer number of Chinese tourists." "But while thousands upon thousands of citizens of The People's Republic respectively walk past the icons of their recent past..." "I have come in search of icons of their country's deep past, that largely remain off the beaten track." "Situated just outside Beijing's busy centre, the Institute of Vertebrate Palaeontology and Paleoanthropology, or IVPP, is a world-class research facility." "It also houses a small public museum, filled with dinosaur-age fossils." "The word "dinosaur" translates as "terrible lizard."" "And, in the mid-19th century, it was always assumed that these creatures were exactly that -lizards, albeit gigantic and terrifying ones." "But, starting in the 1990s, strange new fossils began being unearthed in Northern China." "Fossils that revealed features that put a whole new complexion on that image." "Feathers." "And in 2012, a discovery was made that changed the face of the most famous dinosaur of them all." "Curious though it may seem, the fiercest dinosaur of them all," "Tyrannosaurus Rex, may have been clothed in a kind of fuzz of fine feathers." "We know this because a close relative, in China, has just such a covering." "I'm holding a sample, which is about to go into further scientific analysis, which shows these rather simple, almost hair-like, proto feathers." "It's an extraordinary thought to think that a fierce, carnivorous dinosaur might have been clothed in such things." "Yutyrannus Huali lived about 140 million years ago, probably using its fuzzy proto feathers for insulation and warmth." "Strange as it may seem, it's only one of many feathered dinosaur discoveries." "To delve deeper into this mystery, I set off for a remote part of China's north-eastern Liaoning Province." "The landscape of Sihetun hides a turbulent past." "140 million years ago, during the cretaceous heyday of the dinosaurs, this world was blasted by volcanoes that periodically entombed the entire local eco system." "On hand, to be my guide, is one of China's foremost experts in feathered dinosaurs, Professor Xu Xing." "He starts by showing me the local geology, and the reason why this area is nicknamed "the dinosaur Pompeii"." "Well, erm, the rock types here, you can see beautifully the horizontal stratification." "But we can actually get a bit closer here, can't we?" "So, those yellow bands, they are volcanic ash." "You see." "So, this is the volcanic ash cloud that comes down very suddenly..." "Right. .." "Kills the fauna?" "Right." "And also it tells you there are multiple events." "I can see them, just looking in front of me, every few centimetres, in fact..." "Right, exactly." "..Up to, perhaps, half a metre at most." "It means there were eruptions at a very regular, perhaps thousands-of-year, intervals." "Right." "But enough time between them for the lake to get re-colonised again." "Right, right." "But what about extracting it?" "It's obviously quite soft." "I guess you have to be very careful when you're excavating to keep fossils in one piece." "But, still, new finds turning up every year." "So, it's worth it." "Yes, yeah, that sounds amazing!" "You know, these days before the cavemen, oh, we have some great stuff." "The ancient name for this region is the Jehol, meaning "hot springs."" "Yet, for most of the 20th century, the true extent of the fossil riches buried beneath its volcanic ashes was unknown." "These are the first known fossils from the Jehol area." "This is a larva of a mayfly, so-called Ephemeroptera." "Mayflies, of course, live for but a day as adults, and even the adults have been found fossil." "This is a carapace of a freshwater crustacean, called Eosestheria, which is probably the most abundant fossil in Jehol." "And er, well, this is a rather charming little fish, called Lycoptera." "Sometimes you can find a mass grave of these charming little fish." "And that, of course, begins with "L"." "taken together, you get "E", "E", "L"." "And for a long time these were the only fossils known from the Jehol formation." "Of course, in the '70s and '80s they were joined by all sorts of wonderful new discoveries." "Charming as they are, it's hard to believe these little creatures were the warm-up act to some of the great fossil finds of the last 20 years." "From stunningly preserved fish and flowering plants to early mammals and reptiles." "And, most important, feathered dinosaurs of every conceivable variety." "One of the most significant of these resides a day's drive from Sihetun." "'This is the Beipiao Geopark, 'and I am assigned the ever-helpful Ms Chung as my guide.'" "Thank you." "After you." "'The park is a powerful symbol of China's increasing affluence, 'as well as pride in its new-found fossil riches." "'Though, I have been warned, it takes a few liberties with 'the past that might not be exactly to my taste.'" "Now, here must be one of the dino birds, freely rendered." "'Bred over several square kilometres, the park is undeniably spectacular.'" "Ah, now, here - a fossil forest." "Yes." "Er, there is about 1,000 fossils." "And, oh, my goodness, here's a volcano." "'And at one end, in a kind of gigantic greenhouse, 'a vast cross section of rock has been dug out to reveal 'some of the local discoveries.'" "So is this the real rock here?" "Yes." "Wow, what a sight." "And I guess the treasure, the specimens, are dotted about on the bottom here." "But they're not actually where they were found." "These are, kind of, scattered about, as it were, in an ordinary museum, but placed on the strata to give them a kind of simulated reality." "The treasures inside the museum, both fossil and man-made, conjure forth an image of ancient Jehol and its unique feathered inhabitants." "'Some of the precious relics here can provide us with a valuable 'insight into the eco system our feathered dinosaurs inhabited.'" "You can almost see the frog laid out going, 'Ooh!" "' at the moment of death." "'Including some nearer our own family tree.'" "This is a very, very important fossil." "It's a mammal." "Not much bigger than a mouse, but it's a very important mammal because it's the first placental mammal known in such detail." "The placentals, of course, include womb-bearing mammals." "Everything from porcupines to tigers, and, of course, ourselves." "And, among all the mammals, this is the one that lies close to our line of descent." "But the star attraction isn't a mammal, it fed on them." "The object of my quest, Sinosauropteryx." "Yes, and I can see it's the holotype." "The actual specimen on which the name, Sinosauropteryx, hangs." "And it really is a wonderful example." "Sinosauropteryx was the first dinosaur to be clearly identified as feathered, back in 1996." "I'm just trying to see, from this distance, whether I can see the feathers." "I think I probably need to get up closer." "I think, yes, up on the tail there." "I can just see a hint of them." "But it's a specimen preserved down to the last fingernail." "Sinosauropteryx lived about 120 million years ago, and was a carnivorous raptor, coated in primitive feathers." "And those feathers weren't just monochrome." "Using pioneering techniques, scientists have been able to suggest the original colours of the fossilised plumage." "By examining microscopic structures called melanosomes, that are associated with pigmentation, it's now believed the dinosaur was probably red-brown in colour." "With stripes in its tail, which were likely there for display." "But here, they don't appear to take such findings too literally." "Rendering Sinosauropteryx as one of a series of more psychedelically coloured feathered dinosaurs and early birds." "One of these garish recreations might seem somewhat familiar." "It's called Beipiaosaurus, and was discovered not far from the Geopark." "Today, its fossilised remains are kept behind the scenes back at the IVPP." "Professor Xu Xing helped to identify and name it back in 1999." "Like all feathered dinosaurs," "Beipiaosaurus was a therapod - a two-legged dinosaur, and thus a relative of the fearsome Tyrannosaurus Rex." "'It must be one of the more bizarre creatures ever to walk on two legs.'" "By the looks of it, very large." "And, also, it's in pieces, I can tell that." "Bone strewn around." "Yeah, many bones." "So, you have to try and put it together." "So, what are the pieces?" "Well, that's a skull." "Oh, I can certainly see lots of really rather tiny teeth." "Yeah, yeah, tiny teeth." "It's probably a herbivorous dinosaur." "So, most of its relatives are not plant-eating, but this one is plant-eating." "Yeah." "And what have we here?" "Here are arms." "Oh, I can see here - is that the feathers?" "Yeah, that's the feathers, so, you can see those are, kind of, primitive feathers." "Oh, they're the simple ones?" "Yeah, simple ones; a little bit like your hair." "On the arm?" "Yeah, actually the whole body covered by feathers." "so you know the whole body was feathered?" "Yes." "And here you see the hind legs, a little bit of a tail here." "And there's some claws there, too." "So, small head, vegetarian, but with powerful claws, and long feathers." "Right." "This is a weird mixture." "If you put it all together, what do you get?" "It is rooted among the meat-eating, fast-moving animals." "But this one is kind of a fat, slow..." "Oh, waddled about." "Yeah." "A bit like me." "Yeah, but they got feathers on their body." "Any living equivalent?" "A little bit like a panda, in dinosaur family." "Oh, so this is the nearest thing the dinosaurs got to ever making a panda?" "That's, er, right." "Well, it just shows that nothing in nature is so strange that it can't be invented twice." "HE LAUGHS" "It may seem improbable that a dinosaur, and a feathered one at that, could evolve to resemble a panda." "But there are clear evolutionary parallels between these two completely unrelated animals." "Like the panda, Beipiaosaurus evolved from meat-eating ancestors to become, primarily, vegetarian." "Both swapped the fast speed and reactions of a predator for the defensive bulk of a herbivore." "And both also retained their long sharp claws, re-purposing them for cutting vegetation rather than rending flesh." "A contemporary of Beipiaosaurus provides an even more striking example of the inventiveness of evolution." "Caudipteryx was also a ground-dwelling, feathered dinosaur." "It, too, had pronounced tail feathers and a beak-like snout." "But it also possessed another characteristic that might make it almost indistinguishable from a flightless bird." "Long, powerful legs." "So, this is a feathered dinosaur called Caudipteryx." "Yeah." "And just so we can prove that right at the start, here are the impressions of the feathers." "Exactly." "And the tail, was that feathered too?" "Yes." "They used that for show, perhaps?" "Er, that's our, our guess." "Or, to scare an enemy off." "Yeah." "A kind of communication display, you know." "Like some birds," "Caudipteryx swallowed stones to help it digest tough vegetation." "Extraordinary preservation means we can still see them in its stomach." "Well, it's a rather wonderful animal." "But this particular feathered dinosaur is likely to have been terrestrial, presumably?" "It's definitely a ground-living animal." "You can tell from the long leg." "So, it's a middle-sized, active, ground-living, feathered dinosaur?" "Right." "There's a modern, flightless bird that bears a rather uncanny resemblance to Caudipteryx." "And can help us fill in the missing evidence, which even fossils don't preserve." "It's the emu." "But at the Royal Veterinary College of London, dinosaur locomotion expert, Professor John Hutchinson, has been studying these fine, if sometimes rather bad-mannered, birds." "Well, of course, John, one of the great things about knowing that dinosaurs and birds are related Mm-hm." "..Means that you can come and study living birds to find out more about dinosaur habits and their transition into birds." "Absolutely." "An emu is a living dinosaur." "And the feet, of course, are poor, pure dinosaurian." "Yeah, they've got those wonderful, scaly, three-toed, clawed feet on them." "But the feathers, of course, not used for flight." "But what function do they have?" "You know, the emu have?" "Yeah, in any bird, feathers have a lot of functions." "In an emu, even though they're flightless, they're using their feathers for insulation, for camouflage, display and communication, all kinds of things - lots of benefits to being feathered." "The other thing, of course, these birds are wonderfully well adapted to, is running." "Oh, yeah." "They have massive leg muscles, and they can sustain a run for quite a while, if they need to." "You know, they're, they're excellent athletes." "So, if we imagine three or four emus running across the Australian plains, and just er, in our minds eye, we might be looking at a little flock of Caudipteryx." "Yeah, Caudipteryx is a lot like an emu in many ways." "A bit smaller body size, but, some of the very bird-like dinosaurs would have looked and behaved much like this, except for having the big tail." "Otherwise, they would have been quite similar." "That one is certainly anxious to join its friends." "Yeah, they are quite social animals." "The emu, and all other ratites, or flightless birds, share a common ancestor that, millions of years ago, was able to fly." "Like this albatross, it did so by running on its powerful legs, flapping its wings and launching itself into the skies." "It's a flight technique some biologists believe to be the origin of bird flight, and is still used by a variety of large, living birds;" "even ground-dwelling peacocks." "There's still more to learn about the links between living birds and feathered dinosaurs from fossils recently found in Liaoning Province." "Its capital city, Shenyang, is the ancient seat of China's Manchu Dynasty." "Their palace still stands today, the remains of another lost world, nestled in a rapidly expanding, modern city." "Cranes, a symbol of long life, you know." "And, before I look further into the history of feathered dinosaurs, with fossils housed in museums," "I'm intrigued by some which seem to be available on the open market." "My guide is local journalist, Zhang Wanlian." "See that's, that's just like you've taken a herring and pressed it down, hard on the rock, isn't it?" "Ah, here we've got a lot of fossils." "That's probably genuine, isn't it?" "That's its counterpart, you see, you can't fake that." "I wonder how much they want for it." "Shall we ask?" "800?" "Yeah." "No, no, it's good value, I know." "It's like being at a fish market, really, except they're 130 million years old." "But I soon find out seeing is not necessarily believing." "You mean this is a fake?" "It's a fake." "Ah." "It's quite a good fake." "This, he's saying that it's perfectly made." "But that's real rock." "This is real rock." "So, they then put this, somehow, on the surface." "You can use lasers." "Lasers?" "!" "Yes, lasers." "Oh, I'm beginning to lose my faith in human nature." "To restore it, I seek out the genuine treasures of" "Liaoning's Paleontological Museum - the biggest of its kind in China." "Hello, nice to meet you." "Very pleased to see you." "The museum's proud director is Professor Sun Ge." "And the building he helped mastermind is designed to suggest the intimate connection between dinosaurs and birds." "What is going on here?" "This is a dinosaur egg." "Oh, so it's symbolic?" "That's right." "It's symbolic of a dinosaur." "And this is a dinosaur bone." "Like ribs?" "That's right. 21 ribs." "So we have 21 ribs sitting on top of a gigantic egg." "That's right, yeah." "Do you think it will go lighter?" "Once inside, Sun Ge treats me to a whistle-stop tour of his museum's exceptional treasures." "We can see, this is new." "You know, when I was in er, you know, er, in certain time we just find, like, this part." "When I first visited China, more than 20 years ago, a provincial museum, packed with precious finds like this, was unimaginable." "As was an entire private gallery for a select few." "This one is one for the real fossil, do not to give the public." "There is, when some leader coming here." "Mm." "This one we call Leefructus." "We'd probably say it was a buttercup." "Oh, yeah, that's right - a buttercup, yeah!" "But the treasure I've come to see has a particularly English connection." "And whilst we've seen parallels to living, flightless birds, this fossil takes us down another path." "Ooh!" "Before me lies one of the most precious possessions of the Shenyang Museum." "It's the oldest known feathered dinosaur." "Probably 160 million years old." "It's called Anchiornis." "The size of, perhaps, a very small chicken." "I can see a, kind of, black fuzz on the surface of the slab... which are the remains of the fossil feathers." "I can see all four limbs, spread-eagled out." "But both the legs and the arms had feathers on them." "It probably wasn't a very good flier, because the feathers are very simple in design." "It could probably leap from tree to tree, rather than be capable of true flight." "The full name of this remarkable animal is Anchiornis huxleyi, named after the 19th Century scientist, TH Huxley." "And Huxley it was who played a pivotal role in the debate about the origin of birds." "Covered in black feathers with a red head crest, at 160 million years old, this gliding animal is the oldest known bird-like dinosaur." "It's named for Thomas Henry Huxley, Darwin's bulldog, who was the first scientist to suggest a link between dinosaurs and birds." "And the fossil that convinced him of this was discovered, not in China, but in Germany, more than a century and a half ago." "I'm here in southern Germany, in Bavaria, near a little town called Sonthofen." "Behind me is a vast quarry." "In the late 18th Century, they discovered that the very fine limestones here were excellent for making lithographic plates." "And the limestone, ever since, has been known as the lithographic limestone." "But it also contains fossils." "And, in 1860, the most important fossil of all was found - a single feather of the extinct bird, Archaeopteryx." "On hand to show me the quarry where Archaeopteryx was discovered is Dr Martin Roper, director of the local museum in nearby Sonthofen." "Oh, yes." "Yes, you can see it." "I can see the beautiful, horizontal stratification." "Every one of those little lines..." "Yes." "..represents a former sea floor, doesn't it?" "Yes, yes." "In this lagoon." "And you can look here, at this plate." "You see, this bit here." "Yes." "So every time I split, I'm exposing a new, ancient sea floor." "And, of course, it comes up beautifully easily." "There we are." "Ah!" "So, that's a little sea star." "So, most of the fossils you find are actually marine creatures." "Yes." "The terrestrial ones are very rare." "It is a place they are very rare." "Back at the end of the Jurassic Period, around 150 million years ago, this vast quarry was a lagoon." "And gradually became so salty, it preserved almost anything that fell into its depths." "Including flying animals." "But before I see Archaeopteryx itself," "I'm reminded that it shared the sky with other unrelated flying vertebrates, who've filled the background of many a dinosaur movie." "The Pterosaurs." "When you look here, you can see the whole skin, er, with a long finger." "And there, yes, it's the wing membrane." "Yes." "Attached to the finger, rather like the wings of a bat." "Yes." "But, of course, it's a reptile." "It's a reptile, it's a flying reptile, yes." "And, I notice, here's the head." "Er, and here's this beautiful skull with, well, pointy teeth." "Yeah." "It was a fish hunter, flying over the water and then we, it can see a fish is cutting him." "Caught the fish." "Yes." "And then flew away again." "Yes." "He was a flying artist." "Obviously, if you can do that - snatch a fish and fly off, you're a fantastic acrobat in the air." "And yet the strange thing is that they didn't survive at the end of the Cretaceous." "They died out." "They died out." "This, this is skin at the end here." "Whether Pterosaurs went extinct because they were out-competed by flying feathered dinosaurs and early birds remains a mystery." "So, what is this?" "Ah." "Well, shall I say, slightly scrappy fossil." "It's only the right wing of a specimen of Archaeopteryx." "So, this is a piece of Archaeopteryx, just the wing?" "Only a piece." "Er, just the wing." "Well, knowing the auction price of Archaeopteryx, this must be the most expensive chicken wing in the world." "Yes, very nice, you see!" "But we have to see how it fits on the whole animal." "I can show you a complete specimen, it's here." "It's the sixth specimen of Archaeopteryx." "So, the whole specimen, one of seven in the world." "Yeah." "Your prize possession, naturally." "Yes, it's the greatest, it's the greatest specimen of Archaeopteryx." "We are very proud to have the original here in our museum." "And, of course, it looks as delicate as a ballet dancer, doesn't it?" "Yes." "And yet, this poor animal probably died in agony." "Yeah." "On the right side you can see both wings, but it is not clear in this specimen, to see the feathers." "You don't see the feathers, so you might mistake it for a dinosaur." "Er, when this specimen came in, into our museum, all thought it is a little dinosaur, but not Archaeopteryx." "Seeing it so clearly, with a small dinosaur-like body and a covering of feathers, it's easy to see how it could represent a link, even a transition, between dinosaurs and birds." "But when this idea was first suggested by Huxley, in 1868, he met with much opposition." "The principal opponent of Archaeopteryx as an evolutionary link was Richard Owen, founder of the Natural History Museum and a brilliant anatomist." "Owen was a pioneer in recognising dinosaurs for what they were." "But he was sceptical about Darwinian evolution and a sworn enemy of Huxley." "So, he chose to downplay the importance of transitional fossils, like Archaeopteryx." "Partly as a result of this caution, the status of Archaeopteryx remained disputed for much of the next century." "So, this is the Berlin specimen." "Beautiful." "It's Archaeopteryx." "You can see here the claws of the fingers, here." "One of the anatomical features that was most controversial was its claws." "Seen clearly on this exact replica of a specimen discovered nearly two decades later, in 1877." "Claws may also have played an unexpected role in the evolution of bird flight." "This is a primitive South American bird, called the hoatzin." "A clumsy flier, its flightless young rely on clawed wings to climb in the trees." "Some scientists argue that climbing and gliding, clawing their way up trees and floating down, was more likely as an origin of flight than the running and flapping alternative suggested by the long legged Caudipteryx." "Back at the IVPP, I see a wonderful fossil that beautifully illustrates what's called the "tree down" hypothesis." "It's a superb aerial predator that lived 30 million years after" "Archaeopteryx, and which could easily be mistaken for an ancient bird of prey, complete with its beautifully preserved feathers." "It's called Microraptor." "Now, what's going on here?" "We've got feathers again." "Yes." "Beautifully shown." "But, also, if you look at it, the feet, the two feet, here and here." "Oh, right." "There are long flight feathers also attached to the feet." "I suppose the first question I should ask you is how do you know it's a dinosaur and not a bird?" "That's the first question somebody would ask about this." "A lot of features, if you look at the skeleton, tell you that it is a dinosaur, definitely a dinosaur." "If this fossil were discovered, say, a hundred years ago, people would say," ""Oh, this is a bird because it gets the beautiful feathers."" "But now we know dinosaurs, early birds so well, so we can tell." "Absolutely certainly this is a dinosaur." "Yes, yes." "So, as usual, the truth is in the bones." "Yeah, so we call it a four-winged dinosaur." "It's got very curved claws and so, does... is that rather suggestive of hanging onto branches?" "Yeah, exactly." "And then, presumably, gliding from branch to branch using its four..." "Four wings." "Wings." "Yeah, that's, er, our guess." "We may not have a living Microraptor to study this beautifully designed animal in the flesh..." "..but here, in an experimental wind tunnel, at Southampton University, they have the next best thing." "He's called Maurice." "Engineer, Colin Palmer, has helped to make him." "So, Colin, this is a life-size model of Microraptor." "Yes." "With real feathers." "With real feathers on here." "The feathers, of course, on all four limbs." "Yes." "Er, and how are the feathers chosen?" "Well, we, we looked at the actual fossil and then we found feathers from existing birds that matched those." "And you can see that they're different." "Out towards the ends of the wings, they're what are called 'primary' or 'flight' feathers." "This side of the feather is much narrower than that side." "As you come closer to the body, they're called secondary feathers, where they're symmetrical." "And then on the legs we've also got these asymmetric flight feathers, like that." "So, what about the functions of the feathers on the legs?" "Well, we tested the model with them in different positions, so we tested it with them down, like that, and then we tested it with them up, like that." "And what we found was, with the legs up, it flew more slowly." "But it was less efficient." "Whereas, for the maximum speed it would fly with the legs down." "and then, as it came into land, so it didn't hurt itself, it would put the legs up and perch." "And, you conclude..." "what do you conclude?" "We concluded that this animal is very good at short flights within a crowded tree environment." "It's very good at leaping from one tree, gliding down to end up on a lower branch in the next tree." "But you've used the word 'glide', that means it wasn't a flapper?" "No, it couldn't flap because it had very, very, weak chest muscles." "So it was not able to flap very much at all, maybe one or two flaps at the most." "So, do you think this kind of model-making is relevant to understanding the origins of flight?" "Well, I think they show us that gliding flight was a step along the way, that the earliest dinosaurs with feathers were not able to fly." "And then animals like this used those feathers in order to glide, and then later they would have evolved into powered flight." "So, we seem to have two competing theories about the origin of feathered flight, both of which have supporting evidence." "They may have climbed and glided, like Microraptor." "Or run and flapped, a path suggested by Caudipteryx and its possible relatives." "But are they mutually exclusive?" "Dr Ashley Heers, currently based at the Royal Veterinary College, thinks she has a solution." "She's been conducting a series of experiments with young birds to try to get to the bottom of how birds, and their varied dinosaur ancestors, learned to fly." "Why do you think chicks, or immature birds, are the best experimental material, as it were, for studying dinosaur theories?" "So, if we just look at their feathers, these guys are just beginning to get their flight feathers out, you can see there." "Yes, yeah." "And, some of the earliest dinosaurs that we see, actually have very similar-looking feathers." "They're relatively symmetrical in shape." "And so, by studying how these feathers function in baby birds, and what they use them for, we may gain some insight into these earlier dinosaurs." "So the lifecycle of the individual bird, in a way, parallels the evolutionary story." "Exactly, so..." "From flightless to flightful." "Exactly." "So, most birds can't fly when they hatch." "And so, if you look at the fossil record, at some of these early dinosaurs, you start out with animals that are clearly flightless, can't fly at all." "And at some point you end up with the very bird-like animals that probably could fly." "And so the question is, what's really going on in-between?" "What are these transitional fossils using their wings for?" "You know, the traditional assumption has been that these early dinosaurs probably don't use those very small wings for flight." "Erm, which these guys don't, but they do use them for other flapping behaviours." "To prove her point, Ashley sets up an improvised test, using high speed photography." "Baby birds really like to hang out in a group, and so, if I want this bird to go up to this perch here, I put a bunch of its friends up there, and his tendency is to want to be with his buddies." "So, hopefully, as opposed to the other way around!" "There you go." "And so, obviously, these guys being babies, it takes a while to train them." "A lot of hens you have to start out pretty close to the top cos they don't exactly know where to go." "Oh, lovely, that was a good one." "Go on, little fella." "Whoa!" "That was nice!" "So, on your dinosaur analogy, you could imagine a feathered dinosaur finding this a useful ability to escape trouble and get up to into a roosting site." "Exactly." "And so we're filming this behaviour on a, you know, a very artificial ramp." "But, the chicks when they first hatch, there's a small period of time when they can't fly yet, and so they may use this behaviour to actually go up a tree." "Scuttle up a tree." "Yeah, exactly." "Seen at ten times slower than normal speed, these five-day-old chicks clearly illustrate why reducing the secrets of bird flight into two mutually exclusive camps might be misguided." "Instead of 'tree down' versus 'run and flap'," "Ashley's experiments show that developing birds use their wings and legs for a variety of different purposes - to get up slopes, slow aerial descents, speed up running, even swim." "Now Ashley has begun collaboration with dinosaur locomotion expert," "Professor John Hutchinson, to try and discover how theropod dinosaurs may have turned these primitive flapping behaviours into flight." "So, what are you doing here?" "Well, we've used the power of computers to represent dinosaur bodies in 3D, using scans of the actual skeletons of real fossil dinosaurs." "And then put them into computer models that represent their whole body shape with flesh and lungs, and everything to study how these animals may have moved, so, what kinds of behaviours." "And, we can predict that using a computer model." "So, where does your work with Ashley come into the picture?" "Yeah, well, the super cool thing that we can do now is combine the computerised approaches that we use with experimental approaches." "And that's where Ashley really comes in perfectly, as she's got this great dataset on how living birds do these unusual flap-running behaviours." "So, we'd like to run those through a computer to ask, well, what did Microraptor or a Caudipteryx do?" "What kind of behaviours were they capable of?" "Or not capable of?" "And then, with an evolutionary sequence, we can address how flight itself may have evolved." "At my old stomping ground, London's Natural History Museum, they've also been using cutting edge science to try and find out more about the origin of bird flight." "They've been re-examining the fossil of Archaeopteryx, Richard Owen and Thomas Huxley fought over more than a century ago." "But they're not looking at its claws, wings or legs." "Impossible though it may seem, they've been studying its brain." "So, Angela, this is the specimen that was studied by Richard Owen." "That's right." "And, er, we're missing the head." "We're not quite missing the head." "We have got most of the skull, which has fallen away from the rest of the specimen." "That's the cast." "Here is the actual original specimen." "So, if we turn it over, we've actually got some of the bones er, from the skull roof, all round the back." "So, this is in three-dimension, which is unlike the Chinese specimens." "Yes." "The Chinese specimens, unfortunately, although they showed lots of marvellous detail, they were all squashed completely flat." "This is the only specimen, of all the known Archaeopteryx specimens, where it was possible to actually take the skull out." "So, what we were able to do was scan this little object, bring it back out into three-dimensions." "And then, because the brain in all birds, including this one, is very, very tightly packed inside the skull, the brain leaves an impression of the, what the brain itself was like." "And is this a bird's mind?" "The way the different parts of the brain are organised, it had big lobes where all the flight co-ordination took place." "It had very big optic lobes so, of course, sight is very important if you're flying." "And we're even able to get the details of the semi-circular canals inside the ear, way back here inside." "Ah, for balance." "Yes." "And the semi-circular canals fall exactly within the range you see in modern birds." "So, could we say, "if it thought like a bird, it was a bird"?" "Yes." "It's a bird but it's not as sophisticated as a modern bird." "It was well-equipped for gliding and possibly a little bit of flapping flight." "And it certainly had good visuals and good balance, just like you need in modern birds." "Archaeopteryx was flight ready, but it was still, primarily, a glider." "So, in Beijing's IVPP, I examined the fossil of an animal the institute's director, Professor Zhou Zhonge, believes is one of the first, if not the first, true birds." "This is Confuciusornis." "Confuciusornis." "Named after..." "Named after Confucius." "The greatest Chinese philosopher." "Greatest Chinese philosopher, yes." "And, well, the first thing that strikes you are these magnificently preserved feathers." "Feathers, yes." "And we know they're flight feathers because of the way they're constructed." "Yeah." "You can see they are asymmetrical, meaning it's, er, for flying purposes." "It's a definite flight feather." "Definitely a flight feather." "We've got a strong flyer here." "Mm-hm." "Well, we've got this extraordinary pair of tail feathers." "Yeah." "But they're proper feathers." "Mm-hm." "And so different from Archaeopteryx." "Yes, different." "Archaeopteryx has a long, bony tail, but not in this bird." "You see, we have a short, bony tail." "They are called 'pygostyle'." "So, it's like a modern bird?" "Like modern bird in the tail." "Now, I believe there are Confuciusornis without the tail feathers." "So, the obvious conclusion is the one without could be the female." "Well, that's the general feeling that, er, those with long tail are male and those without are female." "So, even in those days, the males were likely to have been show-offs." "Yeah." "That's true, yeah." "Now, I've just recently been looking at Archaeopteryx and I can see that this does not have teeth." "No teeth, no teeth at all." "This is another modern feature." "But, on the other hand, it's also primitive, more primitive than modern birds." "Because?" "Yeah." "For instance, you will see big claws." "Ah, we've got the wing claws." "Yeah." "Wing claws." "There is another small, tiny claw." "So, this is a reminder of dinosaur ancestry." "It's a reminder of a dinosaur ancestor." "So, we know so much about this bird." "Mm-hm." "Yet, there's one thing we probably don't know." "Mm-hm?" "Did it sing?" "This bird probably could not make a complicated song." "It's not a song bird." "Ah, right." "Because song bird appeared much later in bird history." "So, we'll have to wait for tens of millions of years..." "Right." "..before we could hear it for the first time." "Before we hear the first bird song, yeah." "So, not all bird features appear at the same time." "Yeah." "They come one after the other." "Right." "Exactly." "Confuciusornis may not have been able to sing, but it had developed a large chest bone to anchor arm muscles, which meant it was probably one of the first such animals to flap its wings and truly fly." "Initial tests on its colouring, suggests its plumage was rather like that of a house sparrow, which is rather less exotic than many people might have expected." "As I prepare to leave China, my thoughts turn to another favourite subject - it's time to mix business with pleasure." "This is a scientific examination of the fauna and flora of the Ge-Hole." "I'm going to start with these little noodles, which I'm told are made out of the roots of ferns." "And we know, of course, the origin of the angiosperms, the flowering plants, was in these rocks, so..." "Mm." "Perhaps we ought to move on to the animal kingdom." "Crustaceans have been around for hundreds of millions of years so, er, they're legitimate." "Plenty of those in Ge-Hole." "Well, we've seen some very nice frog fossils." "A bit tricky to process with chopsticks." "Mm." "It's quite nice when you get used to it." "Then, of course, there are reptiles and I've chosen the snake." "Er, this, er..." "Actually, I'm only joking." "Er, this is really an eel." "So, that's going to take both roles." "And finally, I suppose, star of the show - we do, of course, have, as we know, birds." "And, er, so I have to eat some chicken." "So, you see, you too can acquire a taste for pre-history." "Thanks to discoveries in the Ge-Hole of China, our picture of the dinosaurs will never be quite the same again." "We've seen how they sprouted feathers, developed beaks, and used colour for display." "As well as how some of them learned to climb, glide... and, finally, take flight." "Every species of bird alive today is ultimately descended from these animals." "But the division between birds and dinosaurs seems now a multifarious transition, rather than a sharp line." "The dinosaurs still live among us, shrouded in plumage and song." "In the next episode, we travel forward in time to an age when Europe was covered in dense rainforest." "And a deadly lake captured and recorded the rise of the mammals."