0:00:02 > 0:00:05Dinosaurs - you've probably seen hundreds of them.
0:00:05 > 0:00:09You might think you know what they look like,
0:00:09 > 0:00:14but almost every dinosaur you've ever seen is a work of fiction.
0:00:14 > 0:00:16LOW GROWL You turn on the television,
0:00:16 > 0:00:21it almost feels that we know everything about them,
0:00:21 > 0:00:23and that's not really the case.
0:00:23 > 0:00:27But now, a groundbreaking new exhibition is working
0:00:27 > 0:00:29with the world's leading dinosaur scientists
0:00:29 > 0:00:33to revolutionise the way we see these animals.
0:00:33 > 0:00:36We've found, using computer models, that a human sprinter
0:00:36 > 0:00:40would probably be pretty well matched for a muscular tyrannosaurus.
0:00:40 > 0:00:44Scientists are pushing the frontiers of our knowledge
0:00:44 > 0:00:46in new and surprising ways.
0:00:46 > 0:00:48We can say these dark stripes were not red,
0:00:48 > 0:00:52- black or whatever - they were ginger. - That's just amazing.
0:00:52 > 0:00:56But we've never even found a complete skeleton
0:00:56 > 0:00:59of a Tyrannosaurus rex, the most famous dinosaur.
0:00:59 > 0:01:05So, how on earth have we worked out so much about animals that lived millions of years ago?
0:01:05 > 0:01:10How do we get from an incomplete pile of broken bones to this.
0:01:10 > 0:01:11ROARING
0:01:11 > 0:01:15How do you build a dinosaur?
0:01:38 > 0:01:44I'm Alice Roberts. I'm an anatomist used to working with human bodies.
0:01:44 > 0:01:47It's not hard to put a human skeleton together.
0:01:47 > 0:01:49You only need to look in the mirror
0:01:49 > 0:01:53to get a pretty good idea of where the bones go.
0:01:53 > 0:01:57But what do you do when the bones belong to animals that went extinct
0:01:57 > 0:02:00millions of years ago?
0:02:00 > 0:02:04We all think that we know what dinosaurs looked like.
0:02:04 > 0:02:08We've seen plenty of them - pictures, in films and animations,
0:02:08 > 0:02:10even in toy shops.
0:02:10 > 0:02:13But given that the last of the dinosaurs died out
0:02:13 > 0:02:15about 65 million years ago,
0:02:15 > 0:02:20none of us has ever actually seen a living dinosaur.
0:02:20 > 0:02:23So, how do we know what they looked like
0:02:23 > 0:02:27and how can we be sure that we're getting it right?
0:02:34 > 0:02:36Here in Crystal Palace, in south London,
0:02:36 > 0:02:41you can still see the first dinosaur exhibition that was ever built
0:02:41 > 0:02:42anywhere in the world.
0:02:44 > 0:02:47The sculptures were unveiled in 1854.
0:02:47 > 0:02:51It was the start of an obsession that we've never got over.
0:02:51 > 0:02:55But it wasn't long before the science behind these reconstructions
0:02:55 > 0:02:58had lost credibility.
0:03:00 > 0:03:02Even by the end of the 19th century,
0:03:02 > 0:03:05our ideas about dinosaurs had changed so much
0:03:05 > 0:03:09that these models were already looked upon with scorn.
0:03:11 > 0:03:15This megalosaurus, for instance, is shown walking on all four legs,
0:03:15 > 0:03:17but we now know he would have been bipedal -
0:03:17 > 0:03:20he would have stood on just his hind legs
0:03:20 > 0:03:22and his forelegs would have been quite small
0:03:22 > 0:03:25and lifted right up off the ground.
0:03:25 > 0:03:28When the first iguanodon was discovered,
0:03:28 > 0:03:30only one thumb bone was found,
0:03:30 > 0:03:34so palaeontologists thought it must have been a horn.
0:03:34 > 0:03:37But iguanodon didn't have a horn.
0:03:37 > 0:03:42It's very easy to walk amongst these massive models
0:03:42 > 0:03:46and to laugh at the 19th-century idea of what a dinosaur was like.
0:03:46 > 0:03:49We now know so much more.
0:03:49 > 0:03:54We've worked out a phenomenal amount about the dinosaurs.
0:03:54 > 0:03:56But how have we done that?
0:03:56 > 0:03:59How do you start to get close to animals
0:03:59 > 0:04:03that lived hundreds of millions of years ago?
0:04:14 > 0:04:18From 19th-century London, to 21st-century Los Angeles.
0:04:19 > 0:04:23150 years after the first ever dinosaur exhibition,
0:04:23 > 0:04:27I want to know how we can be sure that we're now getting it right.
0:04:27 > 0:04:31So, I've come to LA's Museum of Natural History.
0:04:31 > 0:04:35The museum is undergoing major redevelopment at the moment,
0:04:35 > 0:04:37and at the centre of it all
0:04:37 > 0:04:40is a multimillion dollar new dinosaur exhibit.
0:04:40 > 0:04:44'Luis Chiappe is director of the museum's Dinosaur Institute
0:04:44 > 0:04:47'and curator of the new exhibition.'
0:04:47 > 0:04:49- Hello, Luis. Hello.- How are you?
0:04:49 > 0:04:51- I'm very well. Nice to meet you.- Likewise.
0:04:51 > 0:04:55'He'll be packing it with everything we know about dinosaurs,
0:04:55 > 0:04:58'from the biggest to the smallest, with the latest science
0:04:58 > 0:05:01'on how they looked, moved and interacted.
0:05:02 > 0:05:06Beyond the fact that the exhibition is about dinosaurs,
0:05:06 > 0:05:07what's the idea behind it?
0:05:07 > 0:05:10It's really how do we know what we know about dinosaurs?
0:05:10 > 0:05:14You're not just presenting facts, you're showing how you got to that knowledge?
0:05:14 > 0:05:20Yes, how do we translate the evidence that we find in the field
0:05:20 > 0:05:21into scientific knowledge.
0:05:21 > 0:05:25- So, can I get a sneak preview? - Sure, of course.- Yeah?- Yes.
0:05:26 > 0:05:29'Our knowledge of dinosaurs has been transformed over recent years,
0:05:29 > 0:05:33'and that means that when it opens, Luis's exhibition
0:05:33 > 0:05:38'will aim to be the most scientifically accurate representation of dinosaurs ever.
0:05:38 > 0:05:40'The science will be brought to life
0:05:40 > 0:05:46'by a wide and varied cast of dinosaurs, but right now,
0:05:46 > 0:05:49'the exhibition hall is a building site.'
0:05:49 > 0:05:54We are approaching the centrepiece of the exhibit, a large platform
0:05:54 > 0:05:57that will support three Tyrannosaurus rex,
0:05:57 > 0:06:00what we call a growth series of Tyrannosaurus rex.
0:06:00 > 0:06:05Because a complete T rex skeleton has never been found,
0:06:05 > 0:06:09Luis's team will have to reconstruct the missing bones.
0:06:09 > 0:06:13Then he'll have to choose poses that reflect the latest scientific thinking
0:06:13 > 0:06:16on how these animals stood and moved,
0:06:16 > 0:06:19and with three T rexs on a single platform,
0:06:19 > 0:06:22he'll even be considering how they interacted.
0:06:22 > 0:06:25All this for animals that went extinct
0:06:25 > 0:06:2865 million years ago.
0:06:28 > 0:06:31But dinosaurs weren't all big and scary.
0:06:31 > 0:06:35We're still learning more about some of T rex's relatives,
0:06:35 > 0:06:38and Luis will also be reconstructing
0:06:38 > 0:06:43a tiny chicken-sized dinosaur called fruitadens.
0:06:43 > 0:06:47As you come in to the other gallery, there's going to be a platform
0:06:47 > 0:06:53with a very large dinosaur, a long neck, called mamenchisaurus,
0:06:53 > 0:06:56and a tiny little one, the tiny fruitadens,
0:06:56 > 0:06:58the smallest dinosaur in North America.
0:06:58 > 0:07:01They have to build fruitadens
0:07:01 > 0:07:04from little more than these fossil remains.
0:07:04 > 0:07:06It's never been reconstructed before,
0:07:06 > 0:07:09so working out what it looked like is a huge challenge.
0:07:09 > 0:07:14And Luis's team will be doing much more than just piecing bones back together.
0:07:14 > 0:07:17They'll be creating a lifelike model of the animal,
0:07:17 > 0:07:20which means adding muscles and skin.
0:07:20 > 0:07:24I think when most of us go to an exhibition like this,
0:07:24 > 0:07:27we don't think about all of the work that's gone into it,
0:07:27 > 0:07:29and an exhibition on this scale
0:07:29 > 0:07:32requires hundreds of people to be working together,
0:07:32 > 0:07:37from scientists, to engineers, to artists, and designers.
0:07:37 > 0:07:39But absolutely none of it would be possible
0:07:39 > 0:07:43without the starting point of the hard evidence,
0:07:43 > 0:07:45the fossils themselves,
0:07:45 > 0:07:48because if we'd never found their bones,
0:07:48 > 0:07:54we wouldn't ever have known that these ancient animals ever existed.
0:08:04 > 0:08:08Luis has come to the southeastern corner of Utah.
0:08:08 > 0:08:10Today, this is Wild West country,
0:08:10 > 0:08:14a stopoff on the way to the Grand Canyon,
0:08:14 > 0:08:17and its past is equally epic.
0:08:17 > 0:08:23All the rocks you can see around here are mostly of Jurassic age,
0:08:23 > 0:08:26so this is prime dinosaur country.
0:08:31 > 0:08:36At the time of the Jurassic, the dinosaurs were in their prime
0:08:36 > 0:08:38and this was their home.
0:08:40 > 0:08:42But it was a very different world.
0:08:45 > 0:08:50Back then, this area was awash with streams and flood plains.
0:08:50 > 0:08:52It was the perfect habitat
0:08:52 > 0:08:56for the largest land animals that have ever lived -
0:08:56 > 0:08:58the sauropods,
0:08:58 > 0:09:01long-necked, plant-eating dinosaurs.
0:09:06 > 0:09:08It's just a phenomenal place.
0:09:08 > 0:09:12It's beautiful and it's filled with clues about...
0:09:12 > 0:09:15the ancient life.
0:09:15 > 0:09:18In a vast desert, most of us wouldn't have a hope
0:09:18 > 0:09:21of finding those clues.
0:09:21 > 0:09:23But if you know what you're looking for,
0:09:23 > 0:09:27the hint of a different colour on the ground is all it takes.
0:09:29 > 0:09:31Let me take a closer look.
0:09:31 > 0:09:33You can see the bones
0:09:33 > 0:09:35right here, and here, and here.
0:09:35 > 0:09:38It's very difficult to see what exactly they may be.
0:09:38 > 0:09:40They're very thin.
0:09:40 > 0:09:45It would probably be worth coming back and cleaning this a little bit
0:09:45 > 0:09:48and taking a closer look at what they may be.
0:09:48 > 0:09:51Amazingly, less than 100 metres away,
0:09:51 > 0:09:54there are more clues to the past.
0:09:54 > 0:09:57Luis's colleague has found the remains of a sauropod.
0:09:59 > 0:10:04There's a piece of rib here that's going into the ground,
0:10:04 > 0:10:06about this angle,
0:10:06 > 0:10:11and then there's a piece of the... a pubis, the hipbone, right here,
0:10:11 > 0:10:13and it's almost complete,
0:10:13 > 0:10:17save for the very back end, which is already starting to weather off.
0:10:17 > 0:10:20Luis has to decide what to do with these finds.
0:10:20 > 0:10:22Starting a new dig is a huge undertaking,
0:10:22 > 0:10:25requiring time and money,
0:10:25 > 0:10:27and he has limited resources.
0:10:27 > 0:10:32We already have two very good sites with long-necked dinosaurs.
0:10:32 > 0:10:35I'm reluctant to open another excavation.
0:10:37 > 0:10:41Just half a mile away is one of those sites.
0:10:41 > 0:10:44Luis's team began work on it a year ago.
0:10:44 > 0:10:46Most of the bones are still embedded in the rock
0:10:46 > 0:10:48and must be painstakingly excavated.
0:10:48 > 0:10:52Luis knows from the layer of rock they're digging
0:10:52 > 0:10:55that this dinosaur died 150 million years ago,
0:10:55 > 0:10:57but he doesn't know what species it is,
0:10:57 > 0:11:02and it's potentially a dinosaur that has never been seen before.
0:11:02 > 0:11:04We are actually collecting in an area
0:11:04 > 0:11:09that has not been sampled, no-one has really worked here before.
0:11:09 > 0:11:13The possibility of having a new species is very, very, exciting.
0:11:13 > 0:11:17A fossil dig is like a murder scene -
0:11:17 > 0:11:21every piece of evidence about what happened 150 million years ago
0:11:21 > 0:11:23has to be salvaged.
0:11:23 > 0:11:27The layout of the entire site will be mapped and the precise location
0:11:27 > 0:11:31of every bone fragment recorded, to help piece together the remains.
0:11:31 > 0:11:36The more complete the skeleton, the easier it will be to identify
0:11:36 > 0:11:39and the greater the likelihood that this dinosaur
0:11:39 > 0:11:42will be turned into an exhibit.
0:11:42 > 0:11:46We have hind limbs, we have forelimbs, we have a lot of the tail,
0:11:46 > 0:11:51we have ribs, we have many parts of the skeleton,
0:11:51 > 0:11:53and now we're starting to uncover the neck.
0:11:53 > 0:11:55I would anticipate
0:11:55 > 0:11:58that we're going to have to keep opening the quarry
0:11:58 > 0:12:04to uncover many other neck vertebra and, hopefully, the skull.
0:12:04 > 0:12:07Working out what species this is
0:12:07 > 0:12:10won't be possible until the bones are back in LA.
0:12:10 > 0:12:15But fossils are fragile and moving them is a risky business.
0:12:19 > 0:12:22Ready? One, two, three, move.
0:12:25 > 0:12:31It has to be 400 pounds at least, right? If not more.
0:12:31 > 0:12:32Go slowly.
0:12:32 > 0:12:36The team begin the precarious task of shifting a femur,
0:12:36 > 0:12:39the single heaviest bone in the dinosaur's body.
0:12:39 > 0:12:43Try to keep in a line, because if we go on this side,
0:12:43 > 0:12:45it's just going to be really difficult.
0:12:45 > 0:12:47Doug, why don't you go that way?
0:12:47 > 0:12:52Because the fossil is so delicate, it's been cased in plaster and reinforced with steel bars.
0:12:52 > 0:12:57'When you're handling bones that are heavy and fragile,
0:12:57 > 0:13:00'that is definitely not an easy process.'
0:13:00 > 0:13:02Down.
0:13:02 > 0:13:07'If, you know, you don't have the right people, the bones can break.'
0:13:07 > 0:13:12It will take many more months of work to excavate the entire skeleton
0:13:12 > 0:13:15and get it back to LA for analysis.
0:13:15 > 0:13:17Good, good.
0:13:19 > 0:13:21But to build an exhibition,
0:13:21 > 0:13:26you don't have to spend months in the desert digging up bones.
0:13:26 > 0:13:28There are other places to find fossils.
0:13:33 > 0:13:36There are plenty of palaeontologists working out in the field
0:13:36 > 0:13:40and excavating new fossils, naming new species every year,
0:13:40 > 0:13:42but there are also scientists
0:13:42 > 0:13:46who are combing through existing collections in dusty store rooms,
0:13:46 > 0:13:49hoping to make new discoveries
0:13:49 > 0:13:52from bones that were found decades, if not centuries ago.
0:13:57 > 0:14:00I've come to the Natural History Museum in Oxford,
0:14:00 > 0:14:04and I'm here to meet Darren Naish.
0:14:04 > 0:14:07He's a palaeontologist who looks for new dinosaurs
0:14:07 > 0:14:10in the back rooms of museums.
0:14:11 > 0:14:15There are always a huge number of specimens behind the scenes...
0:14:17 > 0:14:22..either because they're incomplete, unglamorous, or unidentified.
0:14:22 > 0:14:26Darren, I do love these museum collections, when you come behind the scenes
0:14:26 > 0:14:29and you suddenly feel that you're surrounded by treasures.
0:14:29 > 0:14:33It's amazing to think that there are new discoveries to be made in here as well.
0:14:33 > 0:14:37In a way there are almost too many specimens for the number of experts out there.
0:14:37 > 0:14:40There's new stuff to find in collections.
0:14:40 > 0:14:42You don't have to go out in the field.
0:14:42 > 0:14:45You can rummage through museum drawers. You WILL find something new.
0:14:45 > 0:14:49Recently, Darren and a colleague did exactly that.
0:14:49 > 0:14:50They came across a bone
0:14:50 > 0:14:54that had been lying on a museum shelf since Victorian times.
0:14:54 > 0:14:58It may look unremarkable, but with several unique features,
0:14:58 > 0:15:02it didn't fit with anything that had been found before,
0:15:02 > 0:15:06and it was enough for them to describe a new species.
0:15:06 > 0:15:09It must have been really exciting to name a whole new species of dinosaur.
0:15:09 > 0:15:12Yeah. We realised straight away that, wow,
0:15:12 > 0:15:14this is something completely new.
0:15:14 > 0:15:16Naming a new species, not such a big deal.
0:15:16 > 0:15:18- It's quite easy to do. - Really?- But finding...
0:15:18 > 0:15:22- There are... - For me, you'd think that would be a kind of once in a lifetime,
0:15:22 > 0:15:25wow, I've named a new species of dinosaur, but no?
0:15:25 > 0:15:27No. There's huge swathes of the tree of life,
0:15:27 > 0:15:29there's very little work been done.
0:15:29 > 0:15:31It's quite easy to find new species.
0:15:31 > 0:15:34We're in a golden age of dinosaur discovery.
0:15:34 > 0:15:39- There's about 50 new species of dinosaurs named every year.- Really?
0:15:39 > 0:15:43About 90% of all named dinosaurs have been named since about 1990.
0:15:43 > 0:15:46If you were to generate a discovery curve of dinosaurs over time,
0:15:46 > 0:15:49you'd have a curve that's shaped like this,
0:15:49 > 0:15:52and we're currently on the steep upward curve of the graph.
0:15:52 > 0:15:56Why do you think there's such a craze for naming new dinosaurs at the moment?
0:15:56 > 0:16:01Regions of the world are being explored more that haven't been really looked at much beforehand.
0:16:01 > 0:16:04So, places like southern South America, much of central Asia,
0:16:04 > 0:16:06parts of Africa and Australia,
0:16:06 > 0:16:08more people are going out to those places,
0:16:08 > 0:16:10finding new dinosaurs and bringing them back.
0:16:11 > 0:16:13'And the more we find,
0:16:13 > 0:16:18'the more complete our understanding of the world of the dinosaurs becomes.'
0:16:18 > 0:16:22It makes you realise just what a vast body of knowledge
0:16:22 > 0:16:24we've now amassed about these extinct animals,
0:16:24 > 0:16:27so that a palaeontologist can come along,
0:16:27 > 0:16:33look at a single bone and say, "This must be a whole new species".
0:16:33 > 0:16:37And it also makes you wonder how many other dusty, unloved specimens
0:16:37 > 0:16:42are sitting there on store shelves, just waiting to be recognised.
0:16:58 > 0:17:04'Back in Los Angeles, Luis's team are working on the bones that were dug up in Utah.
0:17:04 > 0:17:11'The next step in turning them into an exhibition is to work out exactly what they are.'
0:17:11 > 0:17:14Well, this is where the fossil bones end up,
0:17:14 > 0:17:17and here the preparators continue the process of excavation,
0:17:17 > 0:17:19this time using delicate tools
0:17:19 > 0:17:22and cleaning away the last of the hard sediment,
0:17:22 > 0:17:25revealing the bone itself.
0:17:25 > 0:17:27It's here in the dino lab
0:17:27 > 0:17:30that the dinosaurs really start to come back to life.
0:17:32 > 0:17:35So, Luis, is this one of the specimens from Utah?
0:17:35 > 0:17:37Yes, it is.
0:17:37 > 0:17:39It looks like it's taking ages
0:17:39 > 0:17:43- to extract this from the stony matrix that has built up around it.- Yeah, yeah.
0:17:43 > 0:17:48Well, Erica's been working on this bone for several weeks.
0:17:48 > 0:17:50It will definitely take years
0:17:50 > 0:17:54for the entire skeleton to be prepared, to be cleaned up.
0:17:54 > 0:17:56Do you have an idea at the moment
0:17:56 > 0:17:59what species of dinosaur this might be from?
0:17:59 > 0:18:02Not entirely, in terms of the species.
0:18:02 > 0:18:04But we know it's a camarasaurid.
0:18:05 > 0:18:09'Camarasaurids were a family of long-necked dinosaurs.
0:18:09 > 0:18:12'We currently know of four different species of them,
0:18:12 > 0:18:16'but Luis is hopeful that he might have found a fifth.'
0:18:16 > 0:18:18So, what features will you be looking at,
0:18:18 > 0:18:23as the bones are cleaned up, to help you refine your identification?
0:18:23 > 0:18:28Well, you'll be looking at the shape of the centrum here,
0:18:28 > 0:18:32the configuration of the different processes, the struts,
0:18:32 > 0:18:35the spines of the vertebra that are, in general,
0:18:35 > 0:18:38very diagnostic, they're very telling.
0:18:38 > 0:18:42You must have to be an amazing anatomist, and you must have to know
0:18:42 > 0:18:44the anatomy of so many different dinosaurs,
0:18:44 > 0:18:47to be able to work out what it is you're looking at?
0:18:47 > 0:18:50Yes, but sometimes it's difficult.
0:18:50 > 0:18:52For example, here...
0:18:52 > 0:18:57we have two bones of one dinosaur.
0:18:57 > 0:19:00Can you figure out what they are?
0:19:00 > 0:19:03Well, mm... I'm a human anatomist
0:19:03 > 0:19:05so this is stretching my expertise somewhat,
0:19:05 > 0:19:08asking me to identify dinosaur bones!
0:19:08 > 0:19:13- And these ones are not very well preserved, I'm sorry.- Brilliant!
0:19:13 > 0:19:16You know, they're fairly kind of flat pieces of bone,
0:19:16 > 0:19:19so I would think maybe this is part of the skull or the jaw.
0:19:19 > 0:19:22- Am I anywhere near? - Yes, you're absolutely right.
0:19:22 > 0:19:27So, what you have here are two lower jaws of a duck-billed dinosaur.
0:19:27 > 0:19:30So, they'd come together in the mid-line somehow?
0:19:30 > 0:19:33Yes, they actually come together right here.
0:19:33 > 0:19:35- SHE CHUCKLES - The other way round!
0:19:35 > 0:19:37Brilliant.
0:19:38 > 0:19:43I know how difficult it can be to piece together an ancient skeleton from fragments,
0:19:43 > 0:19:47but I've only ever worked with one species, humans,
0:19:47 > 0:19:50so I'm really impressed by palaeontologists,
0:19:50 > 0:19:56who have to understand the anatomy of hundreds of different dinosaur species.
0:19:56 > 0:20:00Identifying a dinosaur is just the starting point
0:20:00 > 0:20:03for unlocking its secrets and getting it ready for display.
0:20:03 > 0:20:07It will be years before this dinosaur is ready for the public.
0:20:07 > 0:20:10Instead, the centrepiece of Luis's exhibition
0:20:10 > 0:20:14will be three T rex skeletons that have already been excavated
0:20:14 > 0:20:16and are now ready to be mounted.
0:20:23 > 0:20:26They're being put together in a workshop in New Jersey.
0:20:26 > 0:20:31Resurrecting these awe-inspiring creatures will require mounting the bones in a way
0:20:31 > 0:20:34that reflects the latest scientific understanding
0:20:34 > 0:20:38about posture, movement and behaviour.
0:20:38 > 0:20:44But the fossil remains of each of these animals are desperately incomplete.
0:20:44 > 0:20:49Paul Zawisha is in charge of turning the partial, distorted skeletons,
0:20:49 > 0:20:52into the most up-to-date reflection of scientific knowledge.
0:20:52 > 0:20:54Okey-doke...
0:20:54 > 0:20:59We've got another several weeks and I'm trying to figure out where everyone's at. Tommy?
0:20:59 > 0:21:01Right now we're about...
0:21:01 > 0:21:0450 to 60% finished.
0:21:04 > 0:21:08Everything is articulated. We have to get the new bases built.
0:21:08 > 0:21:10Did you get those hands straightened out?
0:21:10 > 0:21:14- Yeah, I think we finally figured it out!- That's good!
0:21:14 > 0:21:15Two days later.
0:21:15 > 0:21:19Working closely with Luis, Paul and his team will turn
0:21:19 > 0:21:23a miniature model of the three T rexs into a finished exhibit.
0:21:23 > 0:21:28The science will come alive through a combination of art and engineering.
0:21:28 > 0:21:31Luis came out here several months ago,
0:21:31 > 0:21:34he pretty much shifted things around to the scenario
0:21:34 > 0:21:36that's going on here.
0:21:36 > 0:21:39But again, we have a little liberty, because we want to make
0:21:39 > 0:21:42these things come to life, otherwise they just...
0:21:42 > 0:21:45they just don't move and they don't look real.
0:21:45 > 0:21:48Fossilised bones are essentially solid lumps of rock,
0:21:48 > 0:21:53which means that mounting them into a skeleton is an enormous challenge.
0:21:53 > 0:21:56Most of the bones are real, which makes them extremely heavy.
0:21:56 > 0:21:59We're estimating the total weight of the bones
0:21:59 > 0:22:00is a little over a ton.
0:22:00 > 0:22:03The femur's probably...
0:22:03 > 0:22:06a good 200, 250 pounds apiece,
0:22:06 > 0:22:11and we have to set those in place with special rigging devices.
0:22:11 > 0:22:13Heaven forbid one of them falls
0:22:13 > 0:22:16because it would take quite a bit of time to get those back together.
0:22:16 > 0:22:22The entire skeleton will be held together using a custom-made steel frame,
0:22:22 > 0:22:23which needs to be strong enough
0:22:23 > 0:22:26to support the enormous weight of the fossils.
0:22:26 > 0:22:29This will fit in, this will get attached,
0:22:29 > 0:22:32to this other section over here,
0:22:32 > 0:22:34and I'll take one of these ribs here,
0:22:34 > 0:22:38and I'm not sure exactly which one goes where at this point.
0:22:38 > 0:22:43This is number five, so it would...
0:22:43 > 0:22:45lay down right in there.
0:22:45 > 0:22:47That will actually get screwed in at the bottom
0:22:47 > 0:22:51and just settle itself right... right in here.
0:22:51 > 0:22:56Like many T rexs, this one has been given a nickname - Thomas.
0:22:56 > 0:22:59He's one of the best T rex specimens ever discovered
0:22:59 > 0:23:02but is still only 70% complete.
0:23:02 > 0:23:06The missing bones have all been made by Paul's team,
0:23:06 > 0:23:09based on over 30 partial Tyrannosaurus rexs
0:23:09 > 0:23:11that have been found so far.
0:23:11 > 0:23:15This particular rib, you could see where the real rib
0:23:15 > 0:23:18goes together with the artificial rib,
0:23:18 > 0:23:21and this is a section that we had modelled
0:23:21 > 0:23:25and you can see how it blends in with the real rib,
0:23:25 > 0:23:28how it's glued, and it's also pinned on the inside
0:23:28 > 0:23:31so it doesn't break.
0:23:31 > 0:23:34And these ribs will break like icicles.
0:23:34 > 0:23:37If you pick them up the wrong way, they'll just crack,
0:23:37 > 0:23:39break right apart.
0:23:39 > 0:23:42It's not just about hanging the skeletons safely.
0:23:42 > 0:23:47The steel frame will be a work of art in itself, millimetre perfect
0:23:47 > 0:23:51and subtle enough not to draw attention away from the dinosaur.
0:23:51 > 0:23:57Hon Chin is filing down part of the rib armature.
0:23:57 > 0:24:01Again, this is specifically made, like a piece of jewellery.
0:24:01 > 0:24:04It has to hold a specific piece in a special way.
0:24:04 > 0:24:08He's at the point where he's starting to clean up the welds
0:24:08 > 0:24:12and it's going to be gorgeous by the time he's finished, so...!
0:24:12 > 0:24:17The pose in which the dinosaur is hung, while being true to science,
0:24:17 > 0:24:21will also involve a degree of artistic interpretation,
0:24:21 > 0:24:24to really bring the exhibit to life.
0:24:24 > 0:24:27- A little bit more of a sine wave in it.- OK.- It's a little too flat
0:24:27 > 0:24:29and it's not moving well, so...
0:24:29 > 0:24:32Myself and Kevin have been working on the tail
0:24:32 > 0:24:34and I don't like the way it looks,
0:24:34 > 0:24:37and now we're going to be taking that down next week
0:24:37 > 0:24:40and putting a slight bend in that, to give it a bit more life.
0:24:40 > 0:24:44But it's just a visual movement. For instance,
0:24:44 > 0:24:47we might change the toes just a little bit
0:24:47 > 0:24:51to give this thing a sneaking feeling, or a pausing feeling.
0:24:51 > 0:24:54But it's very, very, very subtle.
0:24:54 > 0:24:57You might move one toe just one inch, in one direction,
0:24:57 > 0:25:00and that changes how you visualise this whole thing.
0:25:02 > 0:25:04But putting dinosaurs back together
0:25:04 > 0:25:08is about more than just reconstructing skeletons.
0:25:08 > 0:25:12We need to work out how they stood, how they moved,
0:25:12 > 0:25:17and even understand the details of their physiology,
0:25:17 > 0:25:19and that's not something that's easy to get right.
0:25:23 > 0:25:27For example, we used to think that T rex held its head high,
0:25:27 > 0:25:30with its tail dragging along the ground.
0:25:30 > 0:25:34We saw it as a cold-blooded, lizard-like creature.
0:25:35 > 0:25:41It wasn't until recently that T rex became a forward-thrusting aggressor,
0:25:41 > 0:25:44so fast, it could apparently outrun a car.
0:25:45 > 0:25:48So, how did a T rex stand, and was it really that quick?
0:25:50 > 0:25:52LOW GROWL
0:25:55 > 0:25:59Palaeontologists now have access to an incredible set of clues
0:25:59 > 0:26:03that can help us understand the posture and movement of dinosaurs.
0:26:03 > 0:26:08It's a set of clues that can tell us what they might have looked like in the flesh,
0:26:08 > 0:26:10a set of clues that can even shed light
0:26:10 > 0:26:12on how quickly they might have run,
0:26:12 > 0:26:17and a set of clues that we all see every day.
0:26:17 > 0:26:23Birds are the living descendents of a dinosaur
0:26:23 > 0:26:26because dinosaurs have living descendants.
0:26:26 > 0:26:28Dinosaurs are not extinct
0:26:28 > 0:26:33they did not become extinct at the end of the Mesozoic era.
0:26:34 > 0:26:36'It's an incredible idea
0:26:36 > 0:26:40'but most experts now believe that today's birds
0:26:40 > 0:26:43'are the direct descendents of ancient dinosaurs.'
0:26:45 > 0:26:49- So, does that mean birds actually ARE dinosaurs?- Yes, absolutely.
0:26:49 > 0:26:51How can you be sure about that?
0:26:51 > 0:26:55You have evidence from the skeletal anatomy,
0:26:55 > 0:26:58you have evidence from the shape of the eggs
0:26:58 > 0:27:01and the microstructure of the eggshell,
0:27:01 > 0:27:05a discovery of a wealth of feathered dinosaurs,
0:27:05 > 0:27:08animals that are unquestionably dinosaurs
0:27:08 > 0:27:12and yet have feathers that look just like the feathers of modern birds.
0:27:12 > 0:27:18'It's a discovery that revolutionises the way we see dinosaurs.'
0:27:18 > 0:27:21Even some tyrannosaurs were feathered,
0:27:21 > 0:27:24but the relationship between birds and dinosaurs
0:27:24 > 0:27:27can tell us much more than simply what they may have looked like.
0:27:29 > 0:27:33So, does this mean that we can use living birds
0:27:33 > 0:27:35to help us understand dinosaurs?
0:27:35 > 0:27:36Absolutely.
0:27:36 > 0:27:42You know, you have 10,000 living species of birds
0:27:42 > 0:27:46that are providing you an enormous amount of information
0:27:46 > 0:27:52that you can use to understand the biology of the ancient dinosaurs.
0:27:52 > 0:27:56It's quite amazing, but it also makes a certain degree of sense
0:27:56 > 0:27:58when you really look at them.
0:27:59 > 0:28:04If we want to learn about how the ancient dinosaurs moved,
0:28:04 > 0:28:06and even how quickly they ran,
0:28:06 > 0:28:10few animals can tell us more than ostriches.
0:28:13 > 0:28:19They evolved on an early branch of the avian family tree,
0:28:19 > 0:28:22and like the dinosaurs they're related to,
0:28:22 > 0:28:25they're large, bipedal and flightless.
0:28:27 > 0:28:31- We have some living dinosaurs here to take a look at. - Yeah, a whole field of them.
0:28:31 > 0:28:33Hello, ladies.
0:28:33 > 0:28:35- They're all ladies, are they?- Yes.
0:28:35 > 0:28:38Yes, they're a bit more manageable when they're females.
0:28:38 > 0:28:43'Dr John Hutchinson is based at the Royal Veterinary College just outside London.
0:28:43 > 0:28:46'He's one of the world's leading experts on dinosaur movement
0:28:46 > 0:28:48'and Luis has been consulting him
0:28:48 > 0:28:51'to make sure his T rexs reflect the latest theories.'
0:28:51 > 0:28:55- Can I touch them?- Yeah, yeah, yeah. - Yeah? Will they peck me?
0:28:55 > 0:28:57- They'll peck at your rings. - Will they?
0:28:57 > 0:29:00- Don't peck at my rings. - They'll try to take them off.
0:29:00 > 0:29:02- But they're not very strong at pecking.- No.
0:29:02 > 0:29:05SHE LAUGHS
0:29:05 > 0:29:07I want to feel your feathers.
0:29:07 > 0:29:11Now, this might be what a dinosaur felt like to touch.
0:29:11 > 0:29:15- That's really soft and lovely. - Yeah, just like a cuddly toy.
0:29:15 > 0:29:16Aww!
0:29:16 > 0:29:20- I'm stroking dinosaurs. - Dinosaur.- Yeah.
0:29:20 > 0:29:21Get off me.
0:29:21 > 0:29:26They do look like dinosaurs, especially when you know some dinosaurs were feathered.
0:29:26 > 0:29:30They do, and those feathers are quite primitive in their structure,
0:29:30 > 0:29:33a lot like some of the fossil feathers we find.
0:29:33 > 0:29:37'The similarities aren't just on the surface.
0:29:37 > 0:29:40'We can get a much better understanding of ancient dinosaurs
0:29:40 > 0:29:43'by looking at the anatomy of their modern relatives in depth.
0:29:43 > 0:29:47'And a local farm has recently had to put down one of its ostriches.
0:29:47 > 0:29:52'As an anatomist, I'm very used to dissecting cadavers.'
0:29:52 > 0:29:56Now, I don't usually wear Wellington boots when I'm dissecting, I have to say.
0:29:56 > 0:29:59'But this will be the first time that I've ever dissected a bird
0:29:59 > 0:30:02'or, for that matter, the descendant of a dinosaur.'
0:30:02 > 0:30:05So, John,
0:30:05 > 0:30:08talk me through the anatomy that we can see on the surface.
0:30:08 > 0:30:10That's our heel, the ankle joint,
0:30:10 > 0:30:12but birds walk with that clear of the ground,
0:30:12 > 0:30:14just like their dinosaurian ancestors did.
0:30:14 > 0:30:18And really just two toes, and one main one.
0:30:18 > 0:30:21The middle toe is their dominant toe, just like in a dinosaur,
0:30:21 > 0:30:24the third toe is the major toe of the foot.
0:30:24 > 0:30:28'And there are other similarities to their ancient relatives.'
0:30:28 > 0:30:33I don't know if you can see this, but here's the tip of the wing right here
0:30:33 > 0:30:37- and there's a...- Oh, there's a claw. - ..lovely little claw coming off it.
0:30:37 > 0:30:39- Yeah.- So...- That's at the end of one of the digits
0:30:39 > 0:30:42- on their arms, on their wings?- Yep.
0:30:42 > 0:30:46- And it's just there as a relic of their ancestors.- Mm, yeah.
0:30:46 > 0:30:48'The real clues about dinosaurs
0:30:48 > 0:30:50'come from seeing what the relationship is
0:30:50 > 0:30:54'between a bird's muscles and it's bones.'
0:30:54 > 0:30:57Right away we can see some of the thigh muscles here.
0:30:57 > 0:31:00- You can see this lovely... - Yeah, I can see these.- ..red colour,
0:31:00 > 0:31:02beautiful beefy muscle.
0:31:02 > 0:31:06So, based on dissections like this, how accurately do you think
0:31:06 > 0:31:10you can reconstruct the musculature of extinct dinosaurs?
0:31:10 > 0:31:14You can look at any bone and tell something about the soft tissue anatomy of the animal,
0:31:14 > 0:31:15from the scars,
0:31:15 > 0:31:18the muscle scars and ligament and tendon scars on the bones,
0:31:18 > 0:31:22that are attachment points for all these things
0:31:22 > 0:31:23that we see here as soft tissue.
0:31:23 > 0:31:29Actually, if I bring a bone over, we can superimpose these two.
0:31:29 > 0:31:32It's got one big muscle attachment right here,
0:31:32 > 0:31:35- and dinosaurs have a muscle scar just like this.- Do they?
0:31:35 > 0:31:40- It appears in the first bipedal dinosaurs, this scar on the outside of the fibula...- Yeah.
0:31:40 > 0:31:43..and is not present in earlier animals.
0:31:43 > 0:31:46So, this is another link between dinosaurs and birds.
0:31:46 > 0:31:51- So, the next time I see a bipedal dinosaur, I must look for this lump. - T rex will have a huge one of those.
0:31:51 > 0:31:54- Yeah.- It's just a massive scar, like this big.- Yeah.
0:31:54 > 0:31:59By estimating the muscle sizes of extinct animals
0:31:59 > 0:32:01and inputting them into computer models,
0:32:01 > 0:32:04John is able to get an incredible new insight
0:32:04 > 0:32:08into how dinosaurs actually moved.
0:32:08 > 0:32:10It's basically running a simulation.
0:32:10 > 0:32:13The computer's figuring out what is the best way to use these muscles,
0:32:13 > 0:32:16given what we've put in, to raise the body up.
0:32:16 > 0:32:19We're not animating it, we're not saying, "Do it this way".
0:32:19 > 0:32:22We're just giving it some basic rules of biology,
0:32:22 > 0:32:25this is what kinds of things you should be trying to do overall,
0:32:25 > 0:32:28- and then it finds the best solution. - Yeah, yeah.
0:32:28 > 0:32:30So, John, you've actually done work
0:32:30 > 0:32:33trying to reconstruct how T rex would have looked,
0:32:33 > 0:32:36how his muscles would have worked, how he would have run.
0:32:36 > 0:32:39What kind of results have you got from that?
0:32:39 > 0:32:42Yeah, we've found, using our computer models, that a human sprinter
0:32:42 > 0:32:46which can do 25 miles an hour or a little faster
0:32:46 > 0:32:50would probably be pretty well matched for a muscular tyrannosaurus,
0:32:50 > 0:32:54or an average human who can run about 15 miles per hour
0:32:54 > 0:32:58would probably be a pretty good match for a skinnier version of a T rex.
0:32:58 > 0:33:00John, I've heard some theories
0:33:00 > 0:33:04where T rex has been put forward as running very fast,
0:33:04 > 0:33:05probably faster than that.
0:33:05 > 0:33:08So, has your work basically disproved that?
0:33:08 > 0:33:12Yeah, I think it's put a lot of doubt in that idea,
0:33:12 > 0:33:15that T rex could run as fast as a racehorse, or even faster,
0:33:15 > 0:33:18so 40 miles an hour, something like that.
0:33:18 > 0:33:22I don't think you'd need an automobile to outrun a T rex.
0:33:22 > 0:33:24We'd have a chance of outrunning them?
0:33:24 > 0:33:28- Running away?- Maybe, but it's never going to happen, thankfully.
0:33:30 > 0:33:33The work of scientists like John has allowed us
0:33:33 > 0:33:36to not only refine our ideas about these extinct animals,
0:33:36 > 0:33:39but has actually transformed our image of them.
0:33:39 > 0:33:43If you think about Tyrannosaurus rex as an example,
0:33:43 > 0:33:46we used to think of him as standing upright like Godzilla,
0:33:46 > 0:33:48but now we know that he couldn't have worked like that.
0:33:48 > 0:33:51If you treat him like an engineering problem,
0:33:51 > 0:33:54inform that using comparative anatomy of living animals,
0:33:54 > 0:33:57and now we know that his body was much more horizontal,
0:33:57 > 0:33:59with his tail held up in the air,
0:33:59 > 0:34:03and our reconstructions are much more robust.
0:34:03 > 0:34:05We're getting as close as we possibly can
0:34:05 > 0:34:09to what this long-dead animal would have looked like.
0:34:09 > 0:34:15But even working out exactly what an adult T rex would have looked like
0:34:15 > 0:34:18only gives you a snapshot of a moment in time.
0:34:18 > 0:34:20To really understand this animal,
0:34:20 > 0:34:24we need to know how it changed over the course of its entire life,
0:34:24 > 0:34:26and that's why Luis's team
0:34:26 > 0:34:31are attempting the first ever reconstruction of a baby T rex.
0:34:31 > 0:34:35There are some small, very tiny segments of the baby,
0:34:35 > 0:34:39but some of them are so small that we can't match anything up.
0:34:39 > 0:34:42Nothing like this has ever been found before.
0:34:42 > 0:34:46It's much harder to recreate a baby than an adult.
0:34:46 > 0:34:50Only a few tiny fragments of a skeleton have ever been found.
0:34:50 > 0:34:53Paul's colleague Tommy is trying to piece together the remains
0:34:53 > 0:34:57from little more than dinosaur dust.
0:34:57 > 0:35:00There's not a lot of pieces and it's only for the skull.
0:35:00 > 0:35:05See, I mean, I've gotten several little pieces put together.
0:35:05 > 0:35:08All these bones had similar colour,
0:35:08 > 0:35:12the texture on the surface was pretty close,
0:35:12 > 0:35:15and a lot of times I'll look at the edge of the bone.
0:35:15 > 0:35:18You'll see this one has a little white and a little black.
0:35:18 > 0:35:22A lot of times it's just trying the piece, seeing if it will fit.
0:35:22 > 0:35:25A lot of people find it boring.
0:35:26 > 0:35:28I don't know, it calms me!
0:35:28 > 0:35:31Although useful for scientists,
0:35:31 > 0:35:34these fossil remains are far too limited
0:35:34 > 0:35:37to bring a baby T rex to life for an audience.
0:35:39 > 0:35:43And that's why the entire baby skeleton will be a model,
0:35:43 > 0:35:48its bones made not from fossils but from foam and resin.
0:35:48 > 0:35:50This is where the artists come in.
0:35:50 > 0:35:53They will produce creatures from their imaginations,
0:35:53 > 0:35:56but they have to be guided by the science
0:35:56 > 0:35:59which provides them with a range of possibilities.
0:35:59 > 0:36:03Ultimately, the animal that they draw or sculpt
0:36:03 > 0:36:07will be a blend of science and art.
0:36:07 > 0:36:12The baby T rex will be sculpted by Doyle, one of Luis's artists.
0:36:12 > 0:36:16When you're doing something that's brand new, that there is no precedent for,
0:36:16 > 0:36:22it can be a little nerve-racking and it can be a lot of fun.
0:36:22 > 0:36:26For my baby T rex, there's no reference for that,
0:36:26 > 0:36:28so there's a lot of interpretation there.
0:36:28 > 0:36:32'With his miniature model of an adult T rex for reference,
0:36:32 > 0:36:36'along with the growing patterns of close relatives of tyrannosaurs,
0:36:36 > 0:36:40'it's possible to work out the likely proportions of the baby.
0:36:40 > 0:36:45'The starting point for the sculpture is a simple illustration.'
0:36:45 > 0:36:47So, I'm going to start off.
0:36:47 > 0:36:51T rex, usually, an adult skull is a great way to measure,
0:36:51 > 0:36:53because it's so big.
0:36:53 > 0:36:55But in babies,
0:36:55 > 0:36:59the skull is going to be thinner,
0:36:59 > 0:37:03and the rule is always that the orbit is going to be larger.
0:37:03 > 0:37:06And also when you look at human babies,
0:37:06 > 0:37:09I've noticed that they are about three heads tall,
0:37:09 > 0:37:14versus an adult human, which is anywhere from seven to nine,
0:37:14 > 0:37:17depending on how tall they are.
0:37:17 > 0:37:21Do you find yourself at all looking at other people's reconstructions
0:37:21 > 0:37:24and thinking, "They've got that wrong"?
0:37:24 > 0:37:26Ah... Yes. SHE CHUCKLES
0:37:26 > 0:37:30There are a bunch of people who are out there
0:37:30 > 0:37:34who are coming from maybe film or special effects
0:37:34 > 0:37:36or something like that.
0:37:36 > 0:37:41They're doing this kind of work from a less informed background.
0:37:41 > 0:37:46So, I'm very privileged to work with a scientist,
0:37:46 > 0:37:50and that's definitely an asset that I don't dare forget.
0:37:50 > 0:37:54- He's looking nice, this T rex, this little two-year-old.- Yeah.
0:37:54 > 0:37:56'But with limited fossil remains,
0:37:56 > 0:38:00'the reconstruction has room for creative licence.'
0:38:00 > 0:38:02So, can you draw me another baby T rex...
0:38:02 > 0:38:04- Sure.- ..based on the same evidence,
0:38:04 > 0:38:07but taking it off in a different direction?
0:38:07 > 0:38:09Let's do the same thing.
0:38:09 > 0:38:11We have our head.
0:38:11 > 0:38:13There's a lot of evidence
0:38:13 > 0:38:16that some of them had feathers,
0:38:16 > 0:38:18and that maybe some of them,
0:38:18 > 0:38:24when they were young, would have had some sort of downy covering
0:38:24 > 0:38:26that would have left in adulthood,
0:38:26 > 0:38:30so that it would have been shedded before they were fully grown.
0:38:30 > 0:38:33This little baby's looking extraordinarily bird-like
0:38:33 > 0:38:35- and has really long legs.- Yeah.
0:38:35 > 0:38:37Is this a reasonable interpretation?
0:38:37 > 0:38:41- There's nothing that says that it can't be this way.- Right.
0:38:41 > 0:38:45Fantastic. It's the same creature, but they're very different.
0:38:45 > 0:38:49The length of the legs is quite extraordinary in this one.
0:38:49 > 0:38:51And I love the feathers.
0:38:51 > 0:38:53That immediately makes it look like
0:38:53 > 0:38:56a completely different creature.
0:38:56 > 0:38:59It shows you there's quite a bit of room for artistic manoeuvre
0:38:59 > 0:39:02- in these reconstructions. - Yes. Definitely, definitely.
0:39:02 > 0:39:06'The questions about Luis's baby T rex
0:39:06 > 0:39:08'run even deeper than its appearance.
0:39:08 > 0:39:13'With such limited fossils, some scientists have actually questioned whether the bones
0:39:13 > 0:39:16'might belong to a different species of dinosaur entirely -
0:39:16 > 0:39:20'something like a T rex, but much smaller.'
0:39:20 > 0:39:24You're presenting a mounted skeleton of this baby T rex,
0:39:24 > 0:39:26and this is the first baby T rex
0:39:26 > 0:39:30that's been found and has been put on display.
0:39:30 > 0:39:34How can you be sure that it is indeed a T rex, if it's a baby,
0:39:34 > 0:39:38because bones change as juveniles turn into adults.
0:39:38 > 0:39:43You can read the characteristics of the bone tissue
0:39:43 > 0:39:47and that can tell you if the animal is a full-grown individual
0:39:47 > 0:39:50or if it's a baby or a very young individual.
0:39:50 > 0:39:55So, we know that perhaps in future, discoveries may prove
0:39:55 > 0:39:59that there was another species of tyrannosaur
0:39:59 > 0:40:02that essentially lived together with T rex
0:40:02 > 0:40:05and that maybe this is a baby of that particular species.
0:40:05 > 0:40:09But at the moment, with information that we have,
0:40:09 > 0:40:14it seems that the most reasonable hypothesis is to say
0:40:14 > 0:40:17that this one represents a baby of a Tyrannosaurus rex.
0:40:17 > 0:40:19I think that's quite brave
0:40:19 > 0:40:23to put something like a baby T rex in this exhibition as a mounted skeleton,
0:40:23 > 0:40:25because there's nothing to compare it with.
0:40:25 > 0:40:29It is our responsibility to make sure that people understand
0:40:29 > 0:40:32that things are not written in stone
0:40:32 > 0:40:38and our scientific conclusions change as we gather more evidence.
0:40:40 > 0:40:42Back in New Jersey,
0:40:42 > 0:40:47the T rexs are nearly complete, and Luis has come to inspect them.
0:40:47 > 0:40:50This is phenomenal, you know.
0:40:50 > 0:40:52- You like it?- It looks awesome.
0:40:52 > 0:40:55It's just fantastic. Really fantastic.
0:40:55 > 0:40:57Everything you thought it would be?
0:40:57 > 0:41:00- Better, better, better.- Good.
0:41:00 > 0:41:02It's hard to describe
0:41:02 > 0:41:07but I feel that it's very dynamic, you know.
0:41:07 > 0:41:11Well, we brought the right-hand foot over the centre line quite a bit...
0:41:11 > 0:41:13- Yeah, I can see that. - ..with a turning, and...
0:41:13 > 0:41:14I can see that.
0:41:14 > 0:41:17- It gives a little... quite a bit of movement.- Yeah.
0:41:17 > 0:41:19I'm glad that you like it, Luis.
0:41:19 > 0:41:21I think it's phenomenal.
0:41:27 > 0:41:29But it's not completely finished.
0:41:32 > 0:41:36Paul and his team need Luis's advice on a couple of issues.
0:41:38 > 0:41:42There are several unknowns, and a complete tail has never been found.
0:41:42 > 0:41:48So, on the older drawings that we have, there's maybe 53 tail vertebra.
0:41:48 > 0:41:51The newer thinking is, there's close to 43.
0:41:51 > 0:41:54Palaeontology, mostly it's a soft science,
0:41:54 > 0:41:57so theories change with new evidence that is found.
0:41:57 > 0:42:00One of the big questions about T rex
0:42:00 > 0:42:04is what it's surprisingly short arms were used for.
0:42:04 > 0:42:07They might have been used to hold on to prey,
0:42:07 > 0:42:11or to push the body up from a sitting position - no-one knows.
0:42:11 > 0:42:14And that's partly because each arm is anchored to the body
0:42:14 > 0:42:16by the shoulder blade or scapula,
0:42:16 > 0:42:20and there's no easy way of telling exactly where that sat.
0:42:20 > 0:42:22With the scapula I've seen
0:42:22 > 0:42:27they've gone up closer to the vertebra on the backbone.
0:42:27 > 0:42:30I've also seen where they're lowered almost to where the belly is.
0:42:30 > 0:42:34There's parts of the front end of the scapula, the coracoids.
0:42:34 > 0:42:38Some people think they go together this much, some think this much.
0:42:38 > 0:42:42But that all has to do with how everything hangs on the front end of this,
0:42:42 > 0:42:45and also how the hands were used.
0:42:45 > 0:42:49Those arms are just about the same size as a human arm.
0:42:49 > 0:42:52The difficulty in placing the scapula on Thomas
0:42:52 > 0:42:55is compounded by the fact that the bones were distorted
0:42:55 > 0:42:59over the millions of years that they spent buried underground.
0:42:59 > 0:43:01They're flattened
0:43:01 > 0:43:06and they don't really have the curvature that they may have had
0:43:06 > 0:43:10when the animal was alive, before.
0:43:10 > 0:43:15It's really difficult to fit them on the sides of the ribcage.
0:43:15 > 0:43:18I guess that that's the nature of the beast.
0:43:18 > 0:43:21We're going to have to find a compromise and we'll live with it.
0:43:24 > 0:43:28Back in LA, there are two months to go before the exhibition opens.
0:43:28 > 0:43:31The three T rexs are now installed.
0:43:35 > 0:43:38Oh, this is a bit different. There are dinosaurs here.
0:43:38 > 0:43:41- Now, these guys I recognise.- Yes.
0:43:41 > 0:43:44So, this is your famous Thomas.
0:43:44 > 0:43:48- Can we get up here?- Sure.- Yeah? - You can... Absolutely. Feel free.
0:43:48 > 0:43:51Face to face with a baby T rex.
0:43:51 > 0:43:55'With three T rexs of different ages on one platform,
0:43:55 > 0:43:58'it's possible for the first time ever to get an understanding
0:43:58 > 0:44:03'of the entire life cycle of this legend of the dinosaur kingdom.'
0:44:03 > 0:44:09- Having a series of juvenile skeletons gives you insights into the way dinosaurs grew?- Absolutely.
0:44:09 > 0:44:14The dinosaurs had growth spurts, so this animal
0:44:14 > 0:44:17- is estimated to have died at the age of two.- Right.
0:44:17 > 0:44:21And this one here is estimated to have died at the age of 13.
0:44:21 > 0:44:24There's, you know, there's a size discrepancy here,
0:44:24 > 0:44:28but they're also 11 years apart.
0:44:28 > 0:44:32- Mm.- Yet this animal is only four years...
0:44:32 > 0:44:38- Yeah.- ..older than this one, yet is enormously bigger than this one.
0:44:38 > 0:44:45What this is telling you is that between 13 and 17
0:44:45 > 0:44:49they were able to add about 1,500 pounds -
0:44:49 > 0:44:52that's, what, 750 kilograms a year.
0:44:52 > 0:44:56Wow. And when you see the two skeletons close to each other like that,
0:44:56 > 0:45:00you really get a kind of physical impression of that.
0:45:00 > 0:45:04'Although Thomas towers over the younger T rexs,
0:45:04 > 0:45:06'even he wasn't fully grown.
0:45:06 > 0:45:08'But at about 17 years old
0:45:08 > 0:45:12'he was already 11 metres long and over three tonnes in weight.'
0:45:12 > 0:45:15- So, this is a juvenile? This enormous skeleton?- Indeed, indeed.
0:45:15 > 0:45:21- This is an animal that probably died at the age of 17.- Right, OK. - So, rather young.
0:45:21 > 0:45:24- So, still a teenager?- And you can tell that it's a juvenile,
0:45:24 > 0:45:28not only based on the histology on the bone tissue,
0:45:28 > 0:45:31for which we have studies of it,
0:45:31 > 0:45:36but also because there are many bones that would fuse
0:45:36 > 0:45:38when the animal was a full-grown...
0:45:38 > 0:45:41- Yeah. - ..that have not yet been fused.
0:45:41 > 0:45:45One of them is here, the calcaneum and the astragalus are completely unfused,
0:45:45 > 0:45:47and both with the tibia.
0:45:47 > 0:45:51'And it's not just the phenomenal speed at which they grew
0:45:51 > 0:45:53'that Luis is shedding light on.
0:45:53 > 0:45:55'The final addition to this platform
0:45:55 > 0:45:59'will be the carcass of another dinosaur - the T rex's dinner.
0:45:59 > 0:46:01'It will give us an insight
0:46:01 > 0:46:03'into how the three T rexs may have interacted.'
0:46:05 > 0:46:07So, how realistic do you think it is
0:46:07 > 0:46:12to show three tyrannosaurs coming together like this?
0:46:12 > 0:46:18We have evidence suggesting that these animals lived in groups.
0:46:18 > 0:46:23It's very reasonable to imagine a scene like this, in which you have a juvenile
0:46:23 > 0:46:25eating a carcass of a duck-billed dinosaur,
0:46:25 > 0:46:31and other individuals coming and being attracted by the carcass.
0:46:31 > 0:46:35If there's going to be a skeleton here representing an edmontosaurus,
0:46:35 > 0:46:38a duck-billed dinosaur, being eaten by the T rexs,
0:46:38 > 0:46:42is there actually evidence that they ate this type of dinosaur?
0:46:42 > 0:46:46You have evidence in the shape of bones of duck-bills,
0:46:46 > 0:46:48like edmontosaurus,
0:46:48 > 0:46:51that have tooth marks, essentially,
0:46:51 > 0:46:57and those marks, those scratches on the bone, coincide well
0:46:57 > 0:47:00with the shape of the crowns of the teeth of Tyrannosaurus rex.
0:47:00 > 0:47:02That's quite forensic.
0:47:02 > 0:47:06- So, you've actually got gnaw marks on a duck-billed dinosaur. - Yes.- Fantastic.
0:47:06 > 0:47:11But the exhibition isn't only about T rex.
0:47:11 > 0:47:14In amongst the 20 major mounts will be fruitadens,
0:47:14 > 0:47:18the smallest dinosaur ever to be found in North America.
0:47:18 > 0:47:23Working from his own illustration, Doyle has created five fruitadens.
0:47:23 > 0:47:28It's the first time that this dinosaur has ever been reconstructed.
0:47:28 > 0:47:31This is full-grown, to scale.
0:47:31 > 0:47:35It's a very small dinosaur and one of the smallest in the world.
0:47:35 > 0:47:37Because the specimen
0:47:37 > 0:47:39is so fragile and sparse,
0:47:39 > 0:47:42the information that we can gather,
0:47:42 > 0:47:45a lot of it is inferred,
0:47:45 > 0:47:49or we're guessing that it fits with a group of animals,
0:47:49 > 0:47:51based on what information we do have.
0:47:51 > 0:47:53We don't have a full skeleton.
0:47:54 > 0:47:58By comparing the size of a forelimb to a thighbone,
0:47:58 > 0:48:01it was clear that fruitadens was bipedal.
0:48:01 > 0:48:04And by studying close relatives, it's possible to get a good idea
0:48:04 > 0:48:07of what a complete skeleton would have looked like.
0:48:07 > 0:48:13The real challenge was to turn that skeleton into a fleshed-out animal.
0:48:13 > 0:48:19Musculature can be inferred from the bones. You can see muscle attachments.
0:48:19 > 0:48:22Every animal has some sort of muscle
0:48:22 > 0:48:24that pulls the leg back
0:48:24 > 0:48:27and also something that supports the leg in front,
0:48:27 > 0:48:29a calf muscle, gastrocnemius,
0:48:29 > 0:48:33or any sort of tendon that would go down to the feet.
0:48:33 > 0:48:37That's something that exists on every animal that walks on land.
0:48:37 > 0:48:40With large teeth for mashing plants
0:48:40 > 0:48:43and sharper teeth for eating insects and worms,
0:48:43 > 0:48:47we can even tell that fruitadens was an omnivore.
0:48:47 > 0:48:50The final piece of the puzzle in recreating this animal
0:48:50 > 0:48:56is its colour, and that's something we can't be sure about.
0:48:56 > 0:49:01If you push things too far, you go with polka dots and purple and pink,
0:49:01 > 0:49:04your audience simply won't believe it.
0:49:04 > 0:49:08But if you draw upon the examples of our living animals,
0:49:08 > 0:49:12we can actually gain a lot just by looking at crocodile skin
0:49:12 > 0:49:17and the colouration and maybe some lizards and fish, even,
0:49:17 > 0:49:19and it will remain believable.
0:49:19 > 0:49:25Like everything in the exhibition, the finished work will have to be approved by Luis.
0:49:25 > 0:49:28So, one thing we need to keep in mind
0:49:28 > 0:49:34is that although we want to have some variation in pattern,
0:49:34 > 0:49:38or in colour, they obviously all need to look the same species.
0:49:38 > 0:49:40You going to give me some freedom
0:49:40 > 0:49:44- to experiment with colours, maybe in the face or the throat?- Yeah...
0:49:44 > 0:49:49I still think that overall we want to stick to standard grey, green, brown.
0:49:49 > 0:49:52I think that it will be nice to be subtle,
0:49:52 > 0:49:54but something that can be...
0:49:54 > 0:49:58can be viewed when you're looking at it from, you know, six feet away.
0:49:58 > 0:50:02Although the colour of fruitadens is unknown,
0:50:02 > 0:50:05new scientific breakthroughs
0:50:05 > 0:50:09are allowing palaeontologists to see some dinosaurs in a way
0:50:09 > 0:50:11that's never been possible before.
0:50:19 > 0:50:22We're still learning more about dinosaurs
0:50:22 > 0:50:24as increasing numbers of specimens come to light,
0:50:24 > 0:50:28but also as the techniques that we use to analyse them
0:50:28 > 0:50:30become more and more sophisticated.
0:50:30 > 0:50:33And I'm off to meet somebody now who's made great discoveries
0:50:33 > 0:50:36in one particular aspect of dinosaur science
0:50:36 > 0:50:40that many people thought would remain hidden for ever.
0:50:42 > 0:50:45Here's another one we're going to look at. I'll just put it in.
0:50:45 > 0:50:48It will take a minute or two to fire up the vacuum.
0:50:48 > 0:50:51'Professor Mike Benton recently came across
0:50:51 > 0:50:54'the remains of a dinosaur that was so exquisitely well preserved
0:50:54 > 0:50:58'that feathers, as well as bones, had fossilised.
0:50:58 > 0:51:03'Incredibly, those feathers can tell us the colour of a dinosaur
0:51:03 > 0:51:05'that lived 125 million years ago.'
0:51:05 > 0:51:10Going back, say, ten years ago, would you ever have imagined that you would have been able
0:51:10 > 0:51:13to tell what colour any dinosaurs would have been?
0:51:13 > 0:51:16No. I mean, I think at that time I, and everybody else,
0:51:16 > 0:51:19would have said that is one of the things we'll never know.
0:51:19 > 0:51:23And so if we just focus up, see what we've got here.
0:51:23 > 0:51:27'Using a scanning electron microscope, Mike can find clues
0:51:27 > 0:51:31'about the pigmentation of these ancient fossil feathers.'
0:51:31 > 0:51:33If we have a look at this...
0:51:33 > 0:51:37- We're at quite high magnification - that's 9,000 times.- Right.
0:51:37 > 0:51:41All of these sausage shapes, then, are melanosomes,
0:51:41 > 0:51:44and in a living feather they would be full of the chemical melanin,
0:51:44 > 0:51:47which, in fact, gives the colour.
0:51:47 > 0:51:48And these sausage-shaped ones
0:51:48 > 0:51:52are a sure indicator of a particular kind of melanin,
0:51:52 > 0:51:56which is the one that gives a black or dark brown colour.
0:51:56 > 0:51:58So, in some cases like this,
0:51:58 > 0:52:02the field of view is completely packed with the sausage-shaped ones,
0:52:02 > 0:52:05so we know this must have been intensely black.
0:52:05 > 0:52:08If they were more loosely spaced,
0:52:08 > 0:52:11we'd know it was a paler colour, maybe dark brown, or grey.
0:52:11 > 0:52:14Right. So, is it just really the presence or absence
0:52:14 > 0:52:18of the black pigments that you're able to ascertain?
0:52:18 > 0:52:22The wonderful thing is that there's another form of melanin that gives a ginger colour.
0:52:22 > 0:52:25And it is packaged in a different shape of melanosome,
0:52:25 > 0:52:28not this kind of cigar-shaped, or sausage-shaped one,
0:52:28 > 0:52:31but a spherical one, a little ball.
0:52:31 > 0:52:34Close it up, get the vacuum going.
0:52:34 > 0:52:39'A sample from a different fossil shows what the structures that carry this ginger pigment look like.'
0:52:39 > 0:52:42Oh, that's entirely different.
0:52:42 > 0:52:46This surface looks as though you've taken a melon baller
0:52:46 > 0:52:49and scooped out lots of little spherical hollows.
0:52:49 > 0:52:53So, what colour would these melanosomes have made?
0:52:53 > 0:52:55This is definitely ginger.
0:52:55 > 0:52:59If you look at a ginger hair from a mammal or a human being, that's what you'd see also.
0:52:59 > 0:53:04So, is it relatively easy to compare your dinosaur feathers
0:53:04 > 0:53:08with what's already known about the feathers of living birds,
0:53:08 > 0:53:12to get that comparison, to know what colours you were looking at here?
0:53:12 > 0:53:15We can put the specimens in one after the other.
0:53:15 > 0:53:17There's the modern one, there's the fossil.
0:53:17 > 0:53:19Spot the difference. No difference at all.
0:53:19 > 0:53:23And who on earth would have thought a dinosaur is close to a bird?
0:53:23 > 0:53:26But there we are, it's kind of proved in the skeletons
0:53:26 > 0:53:30and now, if you like, proved in the anatomy of the feathers.
0:53:30 > 0:53:34'For those few dinosaurs from whom fossilised feathers have been found,
0:53:34 > 0:53:36'largely in China,
0:53:36 > 0:53:39'we can now put the finishing touches to a reconstruction.'
0:53:39 > 0:53:40Has this changed the way
0:53:40 > 0:53:43that artists are painting their reconstructions, then?
0:53:43 > 0:53:45We've got some dinosaurs
0:53:45 > 0:53:48where you've got a very good idea exactly what they look like.
0:53:48 > 0:53:51Yes, it is changing the way people view them.
0:53:51 > 0:53:54If we have a look at these paintings of sinosauropteryx,
0:53:54 > 0:53:57which is one of the lovely little dinosaurs,
0:53:57 > 0:53:59this was probably done five or six years ago.
0:53:59 > 0:54:02It looks a bit odd. They've got the texture of the feathers
0:54:02 > 0:54:05and that's more or less what we would believe from the fossil,
0:54:05 > 0:54:08but they've made it a strange sea green kind of colour.
0:54:08 > 0:54:12A few years later, the same artists are able to produce
0:54:12 > 0:54:15a picture like this, which shows the same dinosaur,
0:54:15 > 0:54:17but with a very definite
0:54:17 > 0:54:22ginger, white, ginger, white sort of barber's pole stripe on the tail.
0:54:22 > 0:54:26- So, this is based on your analysis of colour in this particular dinosaur?- Yes. Yes.
0:54:26 > 0:54:30Of this particular dinosaur we took samples from the dark stripes
0:54:30 > 0:54:32and we can say these dark stripes
0:54:32 > 0:54:37were not red or black or whatever - they were ginger.
0:54:37 > 0:54:38Right. That's just amazing.
0:54:38 > 0:54:41So, this is more than just being able to put a bit of colour
0:54:41 > 0:54:43on your illustrations -
0:54:43 > 0:54:47it's actually telling you something quite important about dinosaurs?
0:54:47 > 0:54:52Yes. It may say something about behaviour, which we wouldn't have thought we could ever get to.
0:54:52 > 0:54:55If they are coloured, and if they are striped and patterned,
0:54:55 > 0:54:59- there must be some visual purpose, signalling of some kind.- Yeah, yeah.
0:54:59 > 0:55:03Camouflage, or sexual display, or a warning thing -
0:55:03 > 0:55:07you know, "I've got a flash of colour, don't mess with me", you know.
0:55:07 > 0:55:10So, there's all sorts of reasons they may have had those colours.
0:55:12 > 0:55:16These new discoveries really do bring dinosaurs
0:55:16 > 0:55:19right out of the realm of the mythical and the fantastical.
0:55:19 > 0:55:23They're not imagined creatures at all, they are real.
0:55:23 > 0:55:26And with some of them, when we have all this information,
0:55:26 > 0:55:29we can look at a reconstruction and know that
0:55:29 > 0:55:33that is a lifelike representation of that animal,
0:55:33 > 0:55:36from the size and shape of its body
0:55:36 > 0:55:39to the way it holds itself, the way it moves,
0:55:39 > 0:55:41down to its colour.
0:55:41 > 0:55:43All of that is rooted in science.
0:55:56 > 0:56:02Back in Los Angeles, last-minute preparations are under way to get the dinosaurs ready for the public.
0:56:06 > 0:56:10It's only now that you get a sense of just how many people have been involved
0:56:10 > 0:56:15in creating this exhibition, from the artists, to the designers,
0:56:15 > 0:56:20to the teams that made the interactive media and the mounts for the dinosaurs,
0:56:20 > 0:56:26all of it bringing to life the decades of research our current scientific understanding relies on.
0:56:28 > 0:56:31CHEERING
0:56:34 > 0:56:38The exhibition consists of over 300 specimens.
0:56:38 > 0:56:40It's taken more than six years to complete
0:56:40 > 0:56:43and cost tens of millions of dollars.
0:56:54 > 0:56:56We've created an exhibit
0:56:56 > 0:57:01that this part of the world has never seen.
0:57:01 > 0:57:06And it's very rewarding for me to think about the millions of kids
0:57:06 > 0:57:10and the millions of people that during the next 20 years
0:57:10 > 0:57:12will visit this exhibit
0:57:12 > 0:57:16and will remember this exhibit for the rest of their lives.
0:57:17 > 0:57:21These animals look like something out of a comic book,
0:57:21 > 0:57:24or a Hollywood studio, but they were real.
0:57:24 > 0:57:27From a pile of dusty bones millions of years old,
0:57:27 > 0:57:30we can put a skeleton back together,
0:57:30 > 0:57:34flesh it out, tell what colour these creatures were,
0:57:34 > 0:57:38and even say something about how they grew up.
0:57:38 > 0:57:43I think this is a unique time to be a dinosaur palaeontologist.
0:57:43 > 0:57:49We're finding so much, discovering new dinosaurs
0:57:49 > 0:57:52and learning new things about them.
0:57:56 > 0:57:58There are certainly still gaps in our knowledge
0:57:58 > 0:58:01but I find it amazing just how much we do know
0:58:01 > 0:58:05about these extinct animals that no-one has ever actually seen alive
0:58:05 > 0:58:09and that lived so many millions of years ago.
0:58:09 > 0:58:12The creatures themselves are utterly awe-inspiring
0:58:12 > 0:58:16but I think so is the incredible amount of work
0:58:16 > 0:58:20and the vast numbers of people involved in reconstructing them
0:58:20 > 0:58:25so that we can come face to face with a dinosaur.
0:58:41 > 0:58:44Subtitles by Red Bee Media Ltd
0:58:44 > 0:58:48E-mail subtitling@bbc.co.uk