0:00:05 > 0:00:10We're living through THE golden age of dinosaur discoveries.
0:00:10 > 0:00:12From all over the world,
0:00:12 > 0:00:16a whole new generation of dinosaurs has been revealed...
0:00:16 > 0:00:22from the biggest giants and the deadliest killers
0:00:22 > 0:00:24to the weird and wonderful.
0:00:33 > 0:00:37From the Arctic to Africa.
0:00:37 > 0:00:39From South America to Asia.
0:00:45 > 0:00:47With the most extraordinary fossils...
0:00:47 > 0:00:52from dinosaur embryos to the exquisitely preserved.
0:00:53 > 0:00:57And using the latest imaging technology,
0:00:57 > 0:01:00cutting-edge research has allowed us to probe deeper
0:01:00 > 0:01:02and reveal more than ever before.
0:01:07 > 0:01:11It gives us our first truly global view of these incredible animals.
0:01:25 > 0:01:28In this episode we look at the new, bizarre
0:01:28 > 0:01:31and extraordinary feathered dinosaurs,
0:01:31 > 0:01:35many of which have only just been discovered.
0:01:35 > 0:01:38Some conquered new worlds.
0:01:38 > 0:01:41Others grew to gigantic sizes.
0:01:48 > 0:01:52As we learn more about the evolution of these feathered beasts,
0:01:52 > 0:01:56they're revolutionising our understanding of life on Earth,
0:01:56 > 0:02:01blurring the boundaries between dinosaurs and birds.
0:02:03 > 0:02:06For over a century, the great dinosaur discoveries
0:02:06 > 0:02:08came from North America and Europe,
0:02:08 > 0:02:12but in the last decade or so, the focus shifted.
0:02:13 > 0:02:18One country now sits at the centre of the new dinosaur revolution -
0:02:21 > 0:02:24China.
0:02:24 > 0:02:29In recent years, spectacular fossils have been uncovered here.
0:02:29 > 0:02:34Amazingly preserved, these fossils revealed exquisite new details.
0:02:34 > 0:02:38And they are giving us incredible glimpses into an alien world,
0:02:38 > 0:02:42a world full of the most bizarre dinosaurs we have ever seen.
0:02:43 > 0:02:47Possibly the strangest of all lived 154 million years ago,
0:02:47 > 0:02:49in the late Jurassic period.
0:02:55 > 0:02:58An animal that looks like nothing else on earth.
0:03:00 > 0:03:03Hiding in these lush forests is Epidexipteryx.
0:03:09 > 0:03:12The size of a pigeon, everything about this creature is odd,
0:03:12 > 0:03:16from the length of its arms to the shape of its teeth.
0:03:21 > 0:03:24This forest is home to many predators
0:03:24 > 0:03:27and being small makes it vulnerable.
0:03:56 > 0:03:58This is Sinraptor.
0:04:01 > 0:04:03A small dinosaur like Epidexipteryx
0:04:03 > 0:04:07would be of no interest to a seven-metre adult.
0:04:07 > 0:04:10But this is a juvenile,
0:04:10 > 0:04:14and Epidexipteryx is a perfect-sized snack.
0:04:51 > 0:04:55Being small does have its advantages,
0:04:55 > 0:04:58because it can escape to the safety of the trees.
0:05:01 > 0:05:05Everything we know about Epidexipteryx
0:05:05 > 0:05:09comes from an incredible fossil, first revealed in 2008.
0:05:11 > 0:05:15It showed an animal with a small skull and large eye sockets,
0:05:15 > 0:05:18and unusually long teeth.
0:05:22 > 0:05:24With toes suited to gripping branches
0:05:24 > 0:05:27and very long arms and hands,
0:05:27 > 0:05:30it suggests that this was a dinosaur well suited
0:05:30 > 0:05:32to living in the trees.
0:05:36 > 0:05:40The extraordinary, elongated third finger
0:05:40 > 0:05:43is another distinctive feature of the group.
0:05:56 > 0:06:00With this and its projecting front teeth, Epidexipteryx
0:06:00 > 0:06:04has the perfect tools to hunt for insects among the trees.
0:06:13 > 0:06:15And one of its favourite foods
0:06:15 > 0:06:18are burrowing beetle grubs that are hiding
0:06:18 > 0:06:20within the trees themselves.
0:06:38 > 0:06:43Prey like this, which is difficult to catch, is quite a prize -
0:06:43 > 0:06:48a prize that can attract unwanted attention.
0:06:50 > 0:06:54Here it's another, larger, Epidexipteryx.
0:07:00 > 0:07:02Stealing food is a common tactic,
0:07:02 > 0:07:05particularly where an animal possesses an expertise.
0:07:12 > 0:07:15There is more to this extraordinary creature
0:07:15 > 0:07:16than first meets the eye.
0:07:16 > 0:07:19Not only was it perfectly designed for life in the trees,
0:07:19 > 0:07:22but the fossil has also revealed
0:07:22 > 0:07:26that it was covered in short, simple feathers.
0:07:26 > 0:07:30Feathers that were likely to have evolved for just one reason -
0:07:30 > 0:07:32to keep it warm.
0:07:32 > 0:07:35But there is one last striking feature -
0:07:35 > 0:07:38four long feathers on its tail.
0:07:38 > 0:07:41These feathers aren't like those of modern birds.
0:07:41 > 0:07:46These are long and ribbon-like.
0:07:46 > 0:07:48Almost certainly, only for show.
0:07:58 > 0:08:02They're the earliest record of ornamental feathers.
0:08:02 > 0:08:04Not just for attraction
0:08:04 > 0:08:06but also to threaten.
0:08:10 > 0:08:14In fact, the very name Epidexipteryx means "display feather",
0:08:14 > 0:08:19and they're among the most bird-like of any dinosaur.
0:08:39 > 0:08:43Stealing among the trees is one thing.
0:08:43 > 0:08:46Stealing on the ground is quite another.
0:08:58 > 0:08:59Only among the trees can you be safe
0:08:59 > 0:09:02from the large predators like Sinraptor.
0:09:02 > 0:09:08On the ground, a few feathers offer no protection.
0:09:12 > 0:09:15The first feathered dinosaur was discovered in 1996
0:09:15 > 0:09:18but lots more would quickly follow.
0:09:18 > 0:09:22It suddenly appeared as if many dinosaur species
0:09:22 > 0:09:23actually had feathers.
0:09:25 > 0:09:29And confirmed what had long been suspected -
0:09:29 > 0:09:33a direct link between dinosaurs and birds.
0:09:33 > 0:09:37A link that can be found in the dinosaurs that
0:09:37 > 0:09:40lived here in the Mongolian desert 85 million years ago.
0:09:44 > 0:09:46This is Saurornithoides.
0:09:46 > 0:09:50It's a member of the Troodon family and we have discovered
0:09:50 > 0:09:53actual fossils of these dinosaurs sitting on a nest.
0:10:05 > 0:10:07It takes days to lay a full clutch of eggs
0:10:07 > 0:10:09and until that's complete,
0:10:09 > 0:10:12this animal won't begin its brooding behaviour
0:10:12 > 0:10:14and start sitting on the next.
0:10:28 > 0:10:32With the Saurornithoides off foraging,
0:10:32 > 0:10:36this unguarded nest provides an invitation for predators.
0:10:38 > 0:10:43This is an Oviraptorid - a bizarre-looking theropod dinosaur.
0:10:43 > 0:10:47With no teeth, they were mostly plant eaters.
0:10:47 > 0:10:50But that doesn't mean it won't take advantage
0:10:50 > 0:10:52of a different kind of lunch.
0:10:56 > 0:10:59We know Oviraptorids were mostly plant eaters
0:10:59 > 0:11:02because of some amazing evidence we have found.
0:11:02 > 0:11:05One fossil in particular was incredibly well preserved.
0:11:05 > 0:11:09Inside its body were small stones - gastroliths.
0:11:10 > 0:11:11Just like a bird,
0:11:11 > 0:11:15it had swallowed these to help digest tough plants.
0:11:16 > 0:11:19But when the remains of two unrelated embryos
0:11:19 > 0:11:22were discovered in an Oviraptorid nest,
0:11:22 > 0:11:25it suggested that some were not just plant eaters
0:11:25 > 0:11:28but may have been nest-raiders as well.
0:12:07 > 0:12:10With two bony projections in its upper jaw,
0:12:10 > 0:12:13this Oviraptorid has the tools to break into an egg
0:12:13 > 0:12:15and get at the precious contents inside.
0:12:26 > 0:12:29It means that a nesting animal like a Saurornithoides
0:12:29 > 0:12:31can never turn its attention away for long.
0:12:50 > 0:12:53But two lost eggs are the least of its problems.
0:13:04 > 0:13:07Here, some nest raiders are bigger than others.
0:13:12 > 0:13:15This is Gigantoraptor.
0:13:21 > 0:13:25Gigantoraptor was discovered in 2007 in the Gobi Desert of Mongolia.
0:13:27 > 0:13:29The sheer size of the bones
0:13:29 > 0:13:31revealed it was unlike anything found before -
0:13:31 > 0:13:36eight metres long and weighing around 1.5 tonnes.
0:13:39 > 0:13:40From its bones, we know
0:13:40 > 0:13:45it was 35 times bigger than its closest Oviraptorid relatives.
0:13:45 > 0:13:49And yet this giant wasn't even fully grown.
0:13:49 > 0:13:54it was "like finding a mouse the size of a cow".
0:14:01 > 0:14:04We don't know for sure
0:14:04 > 0:14:07if such a huge dinosaur like Gigantoraptor
0:14:07 > 0:14:10would have or need feathers.
0:14:17 > 0:14:22In dinosaurs, feathers are usually found as a fine body covering
0:14:22 > 0:14:25and appear to be mainly for keeping warm.
0:14:32 > 0:14:36But feathers were found, and preserved on a fossil
0:14:36 > 0:14:38of one of Gigantoraptor's close relatives.
0:14:42 > 0:14:45And on the forearms and tail are the unmistakeable traces
0:14:45 > 0:14:49of longer symmetrical feathers, similar to a modern bird's.
0:14:55 > 0:14:59It seems certain that Gigantoraptor too was feathered,
0:14:59 > 0:15:03making this the largest feathered animal ever discovered.
0:15:06 > 0:15:10These aren't for flight - Gigantoraptor couldn't fly.
0:15:12 > 0:15:16Nor are they for insulation.
0:15:16 > 0:15:20These are used to intimidate or attract.
0:16:20 > 0:16:23Across the world, discovery after discovery
0:16:23 > 0:16:25has revealed more and more features -
0:16:25 > 0:16:30from nesting to feathers - that were once thought of
0:16:30 > 0:16:34as exclusively bird-like but have now also been found in dinosaurs.
0:16:35 > 0:16:39But the ultimate discovery is perhaps that of a dinosaur
0:16:39 > 0:16:42that lived in Northeast China around 120 million years ago.
0:16:45 > 0:16:48This remote area has revealed
0:16:48 > 0:16:50spectacular fossils in exquisite detail,
0:16:50 > 0:16:54unearthing an astonishing diversity of animals,
0:16:54 > 0:16:57many of which are well adapted to living in trees.
0:16:59 > 0:17:03One particular dinosaur discovery takes this to a whole new level.
0:17:08 > 0:17:10This is Xianglong.
0:17:10 > 0:17:14With curved claws, it's a lizard well suited to climbing trees.
0:17:17 > 0:17:20With prey like this, predators were sure to follow.
0:17:25 > 0:17:27The most common dinosaur in these forests
0:17:27 > 0:17:29doesn't live on the ground.
0:17:33 > 0:17:34Microraptor.
0:17:48 > 0:17:51The fossils of Microraptor are so well preserved
0:17:51 > 0:17:54they clearly reveal every detail of its anatomy.
0:17:54 > 0:17:58With distinctive claws on its first toe,
0:17:58 > 0:18:01this is a member of the raptor family.
0:18:03 > 0:18:07But these claws evolved for climbing, rather than killing.
0:18:09 > 0:18:11At less than a metre long,
0:18:11 > 0:18:14this was a dinosaur perfectly suited to live in the trees.
0:18:28 > 0:18:32Microraptor is small, and perfectly adapted to chasing prey.
0:18:38 > 0:18:41Xianglong, however, has a trick.
0:18:41 > 0:18:44This is a flying lizard.
0:18:44 > 0:18:47It seems to have the perfect skill to escape.
0:18:49 > 0:18:52But the fossils of Microraptor reveal something else.
0:18:55 > 0:18:57This was a feathered dinosaur,
0:18:57 > 0:19:01but these feathers aren't for keeping warm or for show.
0:19:01 > 0:19:05Their structure is plainly visible from the fossils.
0:19:06 > 0:19:10They are very long, veined and most importantly,
0:19:10 > 0:19:13their shape creates a perfect aerodynamic surface.
0:19:17 > 0:19:20And they aren't confined to its forearms.
0:19:20 > 0:19:23Its legs, too, had long feathers.
0:19:29 > 0:19:34These feathers are designed for one thing only - flight.
0:19:36 > 0:19:40Microraptor is a four-winged dinosaur...
0:19:40 > 0:19:42that took to the skies.
0:20:12 > 0:20:14But in these Chinese forests,
0:20:14 > 0:20:18Microraptor isn't the only flying monster.
0:20:25 > 0:20:29Sinornithosaurus. Closely related and larger.
0:20:38 > 0:20:40More than capable of stealing prey.
0:20:43 > 0:20:45But it has larger prey in mind.
0:20:54 > 0:20:56Microraptor is now the hunted.
0:21:06 > 0:21:08Both can fly.
0:21:11 > 0:21:14But this isn't powered flight - it's gliding.
0:21:18 > 0:21:22Recent research has revealed how Microraptor flew.
0:21:22 > 0:21:24It didn't have the muscles for powered flight,
0:21:24 > 0:21:27so instead it made the most of its four wings.
0:21:29 > 0:21:32By holding its rear legs back and to the sides,
0:21:32 > 0:21:35it was able to become an incredibly efficient glider...
0:21:39 > 0:21:43..moving through the forest in a series of long, looping glides.
0:21:49 > 0:21:52Having longer flight feathers on both its arms and legs,
0:21:52 > 0:21:55Microraptor is by far the better glider.
0:22:08 > 0:22:11But with no ability to gain height, the only way is down.
0:22:25 > 0:22:28And once on the ground, the long feathers
0:22:28 > 0:22:31turn from an advantage into weakness.
0:22:31 > 0:22:36Microraptor is barely able to walk, much less run.
0:22:39 > 0:22:41Sinornithosaurus has no such problem.
0:22:41 > 0:22:44On the forest floor, the tables are turned.
0:23:02 > 0:23:05Microraptor has a fortunate escape.
0:23:13 > 0:23:19Sinornithosaurus was one of the first feathered dinosaurs found.
0:23:19 > 0:23:21The fossils are so perfectly preserved
0:23:21 > 0:23:22they have helped us solve
0:23:22 > 0:23:25one of the great dinosaur mysteries.
0:23:26 > 0:23:28For years, the colour of dinosaurs
0:23:28 > 0:23:31was thought impossible to work out.
0:23:31 > 0:23:35In 2010, it was discovered that the feathers on this fossil
0:23:35 > 0:23:37weren't just impressions.
0:23:39 > 0:23:43Under the microscope, tiny structures were revealed
0:23:43 > 0:23:46identical to those found in modern birds -
0:23:46 > 0:23:49structures that contain the pigment.
0:23:49 > 0:23:52Remarkably, by comparing them to living birds,
0:23:52 > 0:23:55we can even work out the true colours.
0:24:01 > 0:24:05The feathers appear to be a combination of reddish-browns,
0:24:05 > 0:24:08yellows, greys and blacks,
0:24:08 > 0:24:10perfectly suited to forest life.
0:24:22 > 0:24:26Another dinosaur living in this forest is Jeholosaurus,
0:24:26 > 0:24:28a small plant eater.
0:24:32 > 0:24:36Recent fossils indicate that this type of dinosaur
0:24:36 > 0:24:39looks after and protects its young.
0:24:58 > 0:25:02With feathers that allow it to blend in with the forest,
0:25:02 > 0:25:05Sinornithosaurus can move, unseen, through the tree tops.
0:25:23 > 0:25:28And Sinornithosaurus is a hunter with a potent secret weapon.
0:25:34 > 0:25:39In 2011, a study of the eyes of this creature revealed
0:25:39 > 0:25:41that it was a predator perfectly capable
0:25:41 > 0:25:44of hunting equally during day and night.
0:25:51 > 0:25:54And a study of its teeth, in 2009,
0:25:54 > 0:25:58showed something that definitely sets it apart from birds.
0:25:58 > 0:26:00Something far more deadly.
0:27:00 > 0:27:04The greatest danger is not simply being outnumbered.
0:27:07 > 0:27:10We have found that Sinornithosaurus teeth
0:27:10 > 0:27:15have unusual and distinctive grooves along their length.
0:27:15 > 0:27:18They resembled those of the venomous Gila monster,
0:27:18 > 0:27:23the grooves in its teeth used to deliver venom into its victim.
0:27:25 > 0:27:28The team even identified what they thought was the location
0:27:28 > 0:27:30of the venom sac in the fossil.
0:27:30 > 0:27:34It appeared Sinornithosaurus could kill with poison.
0:28:12 > 0:28:17This is a far more deadly predator than anyone ever imagined...
0:28:17 > 0:28:22and completes an extraordinary picture of a bizarre lost world.
0:28:24 > 0:28:27All of these discoveries reveal the importance of feathers
0:28:27 > 0:28:30to a whole host of dinosaurs -
0:28:30 > 0:28:35from insulation to defence and finally, flight.
0:28:37 > 0:28:41And Microraptor not only hints at how flight developed,
0:28:41 > 0:28:46but also, that dinosaurs still live amongst us today,
0:28:46 > 0:28:48as birds.
0:29:05 > 0:29:07Subtitles by Red Bee Media Ltd
0:29:07 > 0:29:09E-mail subtitling@bbc.co.uk