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Documentary, BBC Four - How to Build a Dinosaur
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AnimalsTranscript
00:00Dinosaurs. You've probably seen hundreds of them.
00:07You might think you know what they look like.
00:10But almost every dinosaur you've ever seen is a work of fiction.
00:17If you turn on the television, it almost feels that we know everything about them.
00:22And that's not really the case.
00:25But now a groundbreaking new exhibition is working with the world's leading dinosaur scientists to revolutionise the way we see these animals.
00:34We've found using our computer models that a human sprinter would probably be pretty well matched for a muscular Tyrannosaurus.
00:42Scientists are pushing the frontiers of our knowledge in new and surprising ways.
00:47We can say these dark stripes were not red, black or whatever, they were ginger.
00:52That's just amazing.
00:54But we've never even found a complete skeleton of a Tyrannosaurus rex, the most famous dinosaur.
01:01So how on earth have we worked out so much about animals that lived millions of years ago?
01:06How do we get from an incomplete pile of broken bones to this?
01:13How do you build a dinosaur?
01:14How do you build a dinosaur?
01:18How do you build a dinosaur?
01:19How do you build a dinosaur?
01:20How do you build a dinosaur?
01:21How do you build a dinosaur?
01:22How do you build a dinosaur?
01:23How do you build a dinosaur?
01:24How do you build a dinosaur?
01:25How do you build a dinosaur?
01:26How do you build a dinosaur?
01:27How do you build a dinosaur?
01:28How do you build a dinosaur?
01:29How do you build a dinosaur?
01:30How do you build a dinosaur?
01:31How do you build a dinosaur?
01:32How do you build a dinosaur?
01:33How do you build a dinosaur?
01:34How do you build a dinosaur?
01:35How do you build a dinosaur?
01:36How do you build a dinosaur?
01:37How do you build a dinosaur?
01:38How do you build a dinosaur?
01:39How do you build a dinosaur?
01:40How do you build a dinosaur?
01:41How do you build a dinosaur?
01:42used to working with human bodies.
01:45It's not hard to put a human skeleton together.
01:48You only need to look in the mirror
01:50to get a pretty good idea of where the bones go.
01:54But what do you do when the bones belong to animals
01:57that went extinct millions of years ago?
02:01We all think that we know what dinosaurs look like.
02:05We've seen plenty of them.
02:07Pictures in films and animations, even in toy shops,
02:11but given that the last of the dinosaurs died out
02:14about 65 million years ago,
02:17none of us has ever actually seen a living dinosaur.
02:21So how do we know what they look like?
02:25And how can we be sure that we're getting it right?
02:35Here in Crystal Palace in South London,
02:37you can still see the first dinosaur exhibition
02:40that was ever built anywhere in the world.
02:45The sculptures were unveiled in 1854.
02:48It was the start of an obsession that we've never got over.
02:53But it wasn't long before the science behind these reconstructions
02:57had lost credibility.
02:59Even by the end of the 19th century, our ideas about dinosaurs had changed so much
03:06that these models were already looked upon with scorn.
03:12This Megalosaurus, for instance, is shown walking on all four legs,
03:16but we now know he would have been bipedal.
03:18He would have stood on just his hind legs,
03:20and his forelegs would have been quite small and lifted right up off the ground.
03:28When the first Iguanodon was discovered, only one thumb bone was found,
03:32so paleontologists thought it must have been a horn.
03:35But Iguanodon didn't have a horn.
03:39It's very easy to walk amongst these massive models
03:43and to laugh at the 19th century idea of what a dinosaur was like.
03:48We now know so much more.
03:51We've worked out a phenomenal amount about the dinosaurs.
03:55But how have we done that?
03:57How do you start to get close to animals that lived hundreds of millions of years ago?
04:04From 19th century London to 21st century Los Angeles.
04:20150 years after the first ever dinosaur exhibition,
04:24I want to know how we can be sure that we're now getting it right.
04:28So I've come to LA's Museum of Natural History.
04:32The museum is undergoing major redevelopment at the moment,
04:36and at the centre of it all is a multi-million dollar new dinosaur exhibit.
04:42Luis Chiappe is director of the museum's Dinosaur Institute
04:45and curator of the new exhibition.
04:48Hello, Luis. How are you?
04:50I'm very well. Nice to meet you.
04:52Likewise.
04:53He'll be packing the exhibition with everything we know about dinosaurs,
04:56from the biggest to the smallest,
04:58with the latest science on how they looked, moved and interacted.
05:04So beyond the fact that the exhibition is obviously about dinosaurs,
05:07what's the idea behind it?
05:08It's really how do we know what we know about dinosaurs.
05:11So you're not just presenting facts to people,
05:13you're actually showing how you got to that knowledge.
05:15Yes.
05:16How do we translate the evidence that we find in the field into scientific knowledge?
05:23So can I get a sneak preview?
05:24Sure, of course.
05:25Yes.
05:26Our knowledge of dinosaurs has been transformed over recent years.
05:31And that means that when it opens,
05:33Luis's exhibition will aim to be the most scientifically accurate representation of dinosaurs ever.
05:40The science will be brought to life by a wide and varied cast of dinosaurs.
05:45But right now, the exhibition hall is a building site.
05:49We are approaching the centerpiece of the exhibit,
05:53a large platform that will support three Tyrannosaurus rex,
05:58what we call a growth series of Tyrannosaurus rex.
06:01Because a complete T-Rex skeleton has never been found,
06:05Luis's team will have to reconstruct the missing bones.
06:09Then he'll have to choose poses that reflect the latest scientific thinking
06:13on how these animals stood and moved.
06:17And with three T-Rexes on a single platform,
06:20he'll even be considering how they interacted.
06:23All this for animals that went extinct 65 million years ago.
06:28But dinosaurs weren't all big and scary.
06:33We're still learning more about some of T-Rex's relatives,
06:37and Luis will also be reconstructing a tiny chicken-sized dinosaur called Frutadens.
06:44As you come into the other gallery,
06:47there's going to be a platform with a very large dinosaur,
06:52a long neck called Mamenchisaurus,
06:54and a tiny little one, the tiny Frutadens,
06:57the smallest dinosaur in North America.
07:00They have to build Frutadens from little more than these fossil remains.
07:05It's never been reconstructed before,
07:07so working out what it looked like is a huge challenge.
07:11And Luis's team will be doing much more than just piecing bones back together.
07:15They'll be creating a lifelike model of the animal,
07:18which means adding muscles and skin.
07:22I think when most of us go to an exhibition like this,
07:25we don't think about all of the work that's gone into it.
07:28And an exhibition on this scale requires hundreds of people to be working together,
07:33from scientists to engineers to artists and designers.
07:38But absolutely none of it would be possible
07:41without the starting point of the hard evidence, the fossils themselves.
07:46Because if we'd never found their bones,
07:49we wouldn't ever have known that these ancient animals ever existed.
07:55Luis has come to the south-eastern corner of Utah.
08:09Today, this is Wild West Country, a stop off on the way to the Grand Canyon.
08:15And its past is equally epic.
08:18All the rocks you can see around here are mostly of Jurassic age,
08:24so this is prime dinosaur country.
08:28At the time of the Jurassic, the dinosaurs were in their prime.
08:37And this was their home.
08:42But it was a very different world.
08:47Back then, this area was awash with streams and floodplains.
08:51It was the perfect habitat for the largest land animals that have ever lived.
08:57The sauropods.
08:59Long-necked, plant-eating dinosaurs.
09:07It's just a phenomenal place.
09:09It's beautiful and it's filled with clues about the ancient life.
09:15In a vast desert, most of us wouldn't have a hope of finding those clues.
09:22But if you know what you're looking for,
09:24the hint of a different colour on the ground is all it takes.
09:29Let me take a closer look.
09:32You can see the bones right here and here and here.
09:36It's very difficult to see what exactly they may be.
09:39They're very thin.
09:41It was probably worth coming back and cleaning this a little bit
09:46and taking a closer look at what they may be.
09:50Amazingly, less than a hundred metres away,
09:53there are more clues to the past.
09:55Luis's colleague has found the remains of a sauropod.
10:01There's a piece of rib here that's going into the ground,
10:05about this angle.
10:07And then there's a piece of the pubis, the hip bone, right here.
10:12And it's almost complete, save for just the very back end,
10:16which is already starting to weather off.
10:18Luis has to decide what to do with these finds.
10:21Starting a new dig is a huge undertaking requiring time and money,
10:26and he has limited resources.
10:28We already have two very good sites with long-necked dinosaurs.
10:33I'm a little reluctant to, you know, open another excavation.
10:39Just half a mile away is one of those sites.
10:42Luis's team began working it a year ago.
10:44Most of the bones are still embedded in the rock
10:47and must be painstakingly excavated.
10:49Luis knows from the layer of rock they're digging
10:52that this dinosaur died 150 million years ago.
10:56But he doesn't know what species it is,
10:59and it's potentially a dinosaur that has never been seen before.
11:03We are actually collecting in an area that has not been sampled.
11:07No one has really worked here before.
11:09The possibility of having a new species is very, very exciting.
11:15A fossil dig is like a murder scene.
11:18Every piece of evidence about what happened 150 million years ago
11:22has to be salvaged.
11:24The layout of the entire site will be mapped
11:27and the precise location of every bone fragment recorded
11:31to help piece together the remains.
11:33The more complete the skeleton, the easier it will be to identify,
11:38and the greater the likelihood that this dinosaur will be turned into an exhibit.
11:43We have hind limbs, we have forelimbs, we have a lot of the tail, we have ribs,
11:49we have many parts of the skeleton, and now we're starting to uncover the neck.
11:54I would anticipate that we're going to have to keep opening the quarry
11:59to uncover many other neck vertebra and hopefully the skull.
12:06Working out what species this is won't be possible until the bones are back in LA,
12:11but fossils are fragile and moving them is a risky business.
12:20Ready? One, two, three, move.
12:26It has to be 400 pounds at least, right? If not more.
12:32Go slowly.
12:33The team begin the precarious task of shifting a femur,
12:37the single heaviest bone in the dinosaur's body.
12:40Try to keep it aligned because if we go on this side,
12:44it's just going to be really difficult.
12:46I don't want you to go that way.
12:48Because the fossil is so delicate,
12:50it's been cased in plaster and reinforced with steel bars.
12:54When you're handling bones that are heavy and fragile,
12:58that is definitely not an easy process.
13:02If you don't have the right people, the bones can break.
13:09It will take many more months of work to excavate the entire skeleton
13:14and get it back to LA for analysis.
13:17Good, good.
13:18But to build an exhibition, you don't have to spend months in the desert digging up bones.
13:27There are other places to find fossils.
13:35There are plenty of paleontologists working out in the field
13:38and excavating new fossils, naming new species every year.
13:42But there are also scientists who are combing through existing collections
13:46in dusty storerooms, hoping to make new discoveries
13:51from bones that were found decades, if not centuries ago.
13:59I've come to the Natural History Museum in Oxford
14:03and I'm here to meet Darren Nash.
14:06He's a paleontologist who looks for new dinosaurs
14:09in the back rooms of museums.
14:11There are always a huge number of specimens behind the scenes,
14:17either because they're incomplete, unglamorous or unidentified.
14:23Darren, I do love these museum collections when you come behind the scenes
14:28and you suddenly feel that you're surrounded by treasures.
14:31And it's amazing to think that there are new discoveries to be made in here as well.
14:34That's right. In a way, there are almost too many specimens for the number of experts out there.
14:38There's always new stuff to find in collections.
14:41You don't necessarily have to go out in the field and look for dinosaurs.
14:43You can just rummage through museum drawers. You will find something new.
14:47Recently, Darren and a colleague did exactly that.
14:50They came across a bone that had been lying on a museum shelf since Victorian times.
14:54It may look unremarkable, but with several unique features, it didn't fit with anything that had been found before.
15:03And it was enough for them to describe a new species.
15:07It must have been really exciting to name a whole new species of dinosaur.
15:11Yeah, yeah. We realised straight away that, wow, this is something completely new.
15:15Naming a new species, you know, not such a big deal. It's quite easy to do.
15:19Really?
15:21Because for me, you'd think that would be a kind of once in a lifetime,
15:24wow, I've named a new species of dinosaur. But no.
15:27No. There's certain huge swathes of the tree of life.
15:30There's very little work being done, really. It's quite easy to find new species.
15:34We're in a golden age of dinosaur discovery.
15:36There's about 50 new species of dinosaurs named every year.
15:39Really?
15:40About 90% of all named dinosaurs have been named since about 1990.
15:45If you were to generate a discovery curve of dinosaurs over time,
15:48you would have a curve that's shaped like this.
15:50And we're currently on the steep upward curve of the graph.
15:53Why do you think there's such a craze for naming new dinosaurs at the moment?
15:57Regions of the world are being explored more that haven't been really looked at much beforehand.
16:02So places like Southern South America, much of Central Asia, parts of Africa and Australia,
16:06more and more people are going out to those places, finding new dinosaurs and bringing them back.
16:12And the more we find, the more complete our understanding of the world of the dinosaurs becomes.
16:17It makes you realise just what a vast body of knowledge we've now amassed about these extinct animals.
16:26So that a paleontologist can come along, look at a single bone and say,
16:30this must be a whole new species.
16:33And it also makes you wonder how many other dusty, unloved specimens are sitting there on store shelves just waiting to be recognised.
16:42Back in Los Angeles, Luis's team are working on the bones that were dug up in Utah.
17:03The next step in turning them into an exhibition is to work out exactly what they are.
17:11Well, this is where the fossil bones end up and here the preparators continue the process of excavation,
17:19this time using delicate tools and cleaning away the last of the hard sediment, revealing the bone itself.
17:25It's here in the dino lab that the dinosaurs really start to come back to life.
17:33So Luis, is this one of the specimens from Utah?
17:36Yes, it is.
17:38It looks like it's taking ages to extract this from the stony matrix that has built up around it.
17:44Well, Eric has been working on this bone for several weeks.
17:48It will definitely take years for the entire skeleton to be prepared to be cleaned up.
17:56Do you have an idea at the moment what species of dinosaur this might be from?
18:01Not entirely in terms of the species, but we know it's a Camarasaurid.
18:07Camarasaurids were a family of long-necked dinosaurs.
18:11We currently know of four different species of them, but Luis is hopeful that he might have found a fifth.
18:16So what features will you be looking at as the bones are cleaned up to help you refine your identification?
18:24Well, you'll be looking at the shape of the centrum here, the configuration of the different processes,
18:32the struts, the spines of the vertebra that are in general very diagnostic, they're very telling.
18:40You must have to be an amazing anatomist and you must have to know the anatomy of so many different dinosaurs.
18:46to be able to work out what it is you're looking at.
18:49Yes, but sometimes it's difficult. For example, here we have two bones of one dinosaur.
18:58Can you figure out what they are?
19:01Well, I'm a human anatomist, so this is stretching my expertise some more to identify dinosaur bones.
19:10And these ones are not very well preserved, I'm sorry.
19:13Brilliant!
19:15You know, they're fairly kind of flat pieces of bone, so I would think maybe this is part of the skull or the jaw.
19:20Am I anywhere near?
19:21Yes, you're absolutely right. So what you have here are two lower jaws of a duckbill dinosaur.
19:28Oh, brilliant. So they come together in the midline somehow.
19:31Yes, but they actually come together right here.
19:34The other way round. Brilliant.
19:36I know how difficult it can be to piece together an ancient skeleton from fragments, but I've only ever worked with one species, humans.
19:49So I'm really impressed by paleontologists who have to understand the anatomy of hundreds of different dinosaur species.
19:57Identifying a dinosaur is just the starting point for unlocking its secrets and getting it ready for display.
20:05It will be years before this dinosaur is ready for the public.
20:09Instead, the centrepiece of Luis's exhibition will be three T-Rex skeletons that have already been excavated and are now ready to be mounted.
20:17They're being put together in a workshop in New Jersey. Resurrecting these awe-inspiring creatures will require mounting the bones in a way that reflects the latest scientific understanding about posture, movement and behaviour.
20:38But the fossil remains of each of these animals are desperately incomplete.
20:45Paul's the wisher is in charge of turning the partial distorted skeletons into the most up-to-date reflection of scientific knowledge.
20:54Okie doke. We've got another several weeks and I'm just trying to figure out where I run Zach.
20:59Tommy. Right now we're about 50 to 60% finished. Everything is articulated.
21:06We have to get the new bases built.
21:10Did you get those hands straightened out?
21:11Yeah, I think we finally figured.
21:13That's good.
21:15Two days later.
21:17Working closely with Luis, Paul and his team will turn a miniature model of the three T-Rexes into a finished exhibit.
21:25The science will come alive through a combination of art and engineering.
21:30Luis came out here several months ago.
21:32He pretty much shifted things around to the scenario that's going on here.
21:37But again, we have a little liberty because we want to make these things come to life.
21:41Otherwise, they just don't move and they don't look real.
21:46Fossilised bones are essentially solid lumps of rock, which means that mounting them into a skeleton is an enormous challenge.
21:54Most of the bones are real, which makes them extremely heavy.
21:57We're estimating that the total weight of the bones is a little over a ton.
22:02The femurs are probably a good 200, 250 pounds a piece.
22:07And we have to set those in place with special reading devices.
22:12Heaven forbid one of them falls because it would take quite a bit of time to get those back together.
22:16The entire skeleton will be held together using a custom-made steel frame, which needs to be strong enough to support the enormous weight of the fossils.
22:28This will fit in. This will get attached to this other section over here.
22:32And I'll take one of these ribs here, and I'm not sure exactly which one goes where at this point.
22:39This is number five.
22:41So it would lay down right in there.
22:46That will actually get screwed in at the bottom and just settle itself right in here.
22:51Like many T-Rexes, this one has been given a nickname, Thomas.
22:58He's one of the best T-Rex specimens ever discovered, but is still only 70% complete.
23:04The missing bones will be made by Paul's team, based on over 30 partial Tyrannosaurus Rexes that have been found so far.
23:12On this particular rib, you can see where the real rib goes together with the artificial rib.
23:19And this is a section that we had modeled.
23:22And you can see how it blends in with the real rib, how it's glued.
23:28And it's also pinned on the inside so it doesn't break.
23:32And these ribs will break like icicles.
23:35If you pick them up the wrong way, they'll just crack, break right apart.
23:38But it's not just about hanging the skeleton safely.
23:43The steel frame will be a work of art in itself.
23:47Millimeter perfect and subtle enough not to draw attention away from the dinosaur.
23:53Han Jin is filing down part of the rib armature.
23:58Again, this is specifically made like a piece of jewelry.
24:02It has to hold a specific piece in a special way.
24:04And he's at the point now where he's starting to clean up the welds.
24:09And it's going to be absolutely gorgeous by the time he's finished.
24:13The pose in which the dinosaur is hung, while being true to science,
24:19will also involve a degree of artistic interpretation to really bring the exhibit to life.
24:24A little bit more of a sine wave in it because it's a little too flat and it's not moving well.
24:29Myself and Kevin have been working on the tail and I personally don't like the way it looks.
24:36And we're going to be actually taking that down next week and putting a slight bend in that to give it a little bit more life.
24:42But it's just a visual movement.
24:45For instance, we might change the toes just a little bit to give this thing a sneaking feeling or a pausing feeling.
24:51But it's very, very, very subtle.
24:55You might move one toe just one inch in one direction and that changes how you visualise this whole thing.
25:03But putting dinosaurs back together is about more than just reconstructing skeletons.
25:08We need to work out how they stood, how they moved and even understand the details of their physiology.
25:17And that's not something that's easy to get right.
25:25For example, we used to think that T-Rex held its head high with its tail dragging along the ground.
25:30We saw it as a cold-blooded, lizard-like creature.
25:35It wasn't until recently that T-Rex became a forward-thrusting aggressor so fast it could apparently outrun a car.
25:45So how did a T-Rex stand? And was it really that quick?
25:49Palaeontologists now have access to an incredible set of clues that can help us understand the posture and movement of dinosaurs.
26:04It's a set of clues that can tell us what they might have looked like in the flesh.
26:09A set of clues that can even shed light on how quickly they might have run.
26:14And a set of clues that we all see every day.
26:18Birds are the living descendants of a dinosaur because dinosaurs have living descendants.
26:28Dinosaurs are not extinct. They did not become extinct at the end of the Mesozoic era.
26:35It's an incredible idea, but most experts now believe that today's birds are the direct descendants of ancient dinosaurs.
26:43So does that mean birds actually are dinosaurs?
26:44Yes, absolutely.
26:45How can you be sure about that?
26:46You have evidence from the skeletal anatomy. You have evidence from the shape of the eggs and the microstructure of the eggshell.
27:01The discovery of a wealth of feathered dinosaurs, animals that are unquestionably dinosaurs and yet have feathers that look just like the feathers of modern birds.
27:13It's a discovery that revolutionises the way we see dinosaurs. Even some tyrannosaurs were feathered.
27:22But the relationship between birds and dinosaurs can tell us much more than simply what they may have looked like.
27:28So does this mean that we can use living birds to help us understand dinosaurs?
27:37Absolutely. You know, you have 10,000 living species of birds that are providing you an enormous amount of information that you can use to understand the biology of the ancient dinosaurs.
27:53It's quite amazing, but it also makes a certain degree of sense when you really look at them.
28:01If we want to learn about how the ancient dinosaurs moved, and even how quickly they ran, few animals can tell us more than ostriches.
28:10They evolved on an early branch of the avian family tree. And like the dinosaurs they're related to, they're large, bipedal and flightless.
28:26We have some living dinosaurs here to take a look at. Hello ladies.
28:34They're all ladies, are they? Yes, yes. They're a bit more manageable when they're females.
28:40Dr. John Hutchinson is based at the Royal Veterinary College just outside London.
28:44He's one of the world's leading experts on dinosaur movement, and Luis has been consulting him to make sure his T-rexes reflect the latest theories.
28:51Can I touch them? Yeah, yeah, yeah. Will they peck me?
28:56They'll peck at your rings, and they'll try to take them off if they get a good hold, but they're not very strong at pecking.
29:04I want to feel your feathers. Now this might be what a dinosaur felt like to touch.
29:11That's really soft and lovely. Yeah, it's just like a cuddly toy.
29:16Aww. I'm stroking dinosaurs. Get off me.
29:22I think they do look like dinosaurs, especially when you know that some dinosaurs were actually feathered.
29:27They certainly do, and those feathers are quite primitive in their structure, a lot like some of the fossil feathers we find.
29:33The similarities aren't just on the surface. We can get a much better understanding of ancient dinosaurs by looking at the anatomy of their modern relatives in depth.
29:44And a local farm has recently had to put down one of its ostriches.
29:48As an anatomist, I'm very used to dissecting cadavers.
29:53I don't usually wear Wellington boots when I'm dissecting, I have to say.
29:58But this will be the first time that I've ever dissected a bird, or for that matter, the descendant of a dinosaur.
30:04So John, talk me through the anatomy that we can see on the surface.
30:08That's our heel, the ankle joint, but birds walk with that clear of the ground, just like their dinosaurian ancestors did.
30:16And really, just two toes and one main one.
30:19The middle toe is their dominant toe, just like in a dinosaur, the third toe is the major toe of the foot.
30:26And there are other similarities to their ancient relatives.
30:29I don't know if you can see this, but here's the tip of the wing right here.
30:34Oh, there's a claw.
30:35And there's a lovely little claw coming off it.
30:38Yeah. So that's at the end of one of the digits on their arms, on their wings.
30:43And it's just there as a relic of their ancestors.
30:47But the real clues about dinosaurs come from seeing what the relationship is between a bird's muscles and its bones.
30:55Right away we can see some of the thigh muscles here, you can see this lovely red colour, beautiful beefy muscle.
31:02So, based on the sections like this, how accurately do you think you can reconstruct the musculature of extinct dinosaurs?
31:11You can look at any bone and tell something about the soft tissue anatomy of the animal from the scars, as they're called.
31:17The muscle scars and ligament and tendon scars on the bones that are attachment points for all these things that we see here as soft tissue.
31:24Actually, if I bring a bone over, we can superimpose these two.
31:30It's got one big muscle attachment right here, and dinosaurs have a muscle scar just like this.
31:35It appears in the first bipedal dinosaurs, this scar on the outside of the fibula, and is not present in earlier animals.
31:43So this is another link between dinosaurs and birds.
31:45So I must look for that, the next time I see a bipedal dinosaur, I must look for this lung.
31:52T-Rex will have a huge one of those. It's just a massive scar, like this big.
31:55Yeah.
31:57By estimating the muscle sizes of extinct animals and inputting them into computer models,
32:02John is able to get an incredible new insight into how dinosaurs actually moved.
32:07It's basically running a simulation. The computer is figuring out what is the best way to use these muscles, given what we put in to raise the body up.
32:17We're not animating it. We're not saying, do it this way. We're just giving it some basic rules of biology.
32:23This is what kinds of things you should be trying to do overall, and then it finds the best solution.
32:29Yeah, yeah. So John, you've actually done work trying to reconstruct how T-Rex would have looked, how his muscles would have worked,
32:35how he would have run. What kind of results have you got from that?
32:40Yeah, so we've found using our computer models that a human sprinter, which can do 25 miles an hour or a little faster,
32:47would probably be pretty well matched for a muscular Tyrannosaurus.
32:51Or an average human who can run about 15 miles per hour would probably be a pretty good match for kind of a skinnier version of a T-Rex.
32:59John, I've heard some theories where T-Rex has been put forward as running very fast.
33:05Probably faster than that. So has your work basically disproved that?
33:10Yeah, I think it's put a lot of doubt in that idea that T-Rex could run like as fast as a racehorse,
33:16or even faster, like so 40 miles an hour, something like that.
33:20I don't think you'd need an automobile to outrun a T-Rex.
33:24We'd have a chance of outrunning them, running away.
33:27Never going to happen, thankfully.
33:28The work of scientists like John has allowed us to not only refine our ideas about these extinct animals,
33:38but has actually transformed our image of them.
33:41If you think about Tyrannosaurus Rex as an example, we used to think of him as standing upright like Godzilla,
33:46but now we know that he couldn't have worked like that.
33:49We treat him like an engineering problem, inform that using comparative anatomy of living animals,
33:55and now we know that his body was much more horizontal with his tail held up in the air,
34:01and our reconstructions are much more robust.
34:03We're getting as close as we possibly can to what this long dead animal would have looked like.
34:12But even working out exactly what an adult T-Rex would have looked like only gives you a snapshot of a moment in time.
34:19To really understand this animal, we need to know how it changed over the course of its entire life.
34:25And that's why Louise's team are attempting the first ever reconstruction of a baby T-Rex.
34:31There are some small, very tiny segments of the baby, but some of them are so small that it can't match anything up.
34:39Nothing like this has ever been found before.
34:42It's much harder to recreate a baby than an adult.
34:47Only a few tiny fragments of a skeleton have ever been found.
34:51Paul's colleague Tommy is trying to piece together the remains from little more than dinosaur dust.
34:56There's not a lot of pieces and it's only for the skull.
35:01See, I mean, I've gotten several little pieces put together.
35:06These bones had similar color.
35:09The texture on the surface was pretty close.
35:12And a lot of times I'll look at the edge of the bone.
35:15You'll see this one has a little white and a little black.
35:19A lot of times it's just trying the piece, see if it'll fit.
35:23A lot of people find it boring.
35:25I don't know, it calms me.
35:28Although useful for scientists, these fossil remains are far too limited to bring a baby T-Rex to life for an audience.
35:38And that's why the entire baby skeleton will be a model.
35:44Its bones made not from fossils, but from foam and resin.
35:48This is where the artists come in.
35:51They will produce creatures from their imaginations, but they have to be guided by the science,
35:57which provides them with a range of possibilities.
36:00Ultimately, the animal that they draw or sculpt will be a blend of science and art.
36:08The baby T-Rex will be sculpted by Doyle, one of Luis's artists.
36:13When you're doing something that's brand new that there is no precedent for,
36:19it can be a little nerve-wracking and it can be a lot of fun.
36:24For my baby T-Rex, there is no reference for that.
36:27So there's a lot of interpretation there.
36:30With his miniature model of an adult T-Rex for reference,
36:34along with the growing patterns of close relatives of Tyrannosaurs,
36:38it's possible to work out the likely proportions of the baby.
36:41The starting point for the sculpture is a simple illustration.
36:46So I'm going to start off. T-Rex is usually an adult.
36:51The skull is a great way to measure because it's so big.
36:55But in babies, the skull is going to be thinner.
37:00The rule is always that the orbit is going to be larger.
37:03And also when you look at human babies, you'll notice that they are about three heads tall,
37:11versus an adult human, which is anywhere from seven to nine, depending on how tall they are.
37:19Do you find yourself at all looking at other people's reconstructions and thinking,
37:22Oh, God, they've got that wrong?
37:25Uh, yes.
37:27There are a bunch of people who are out there who are coming from maybe film or special effects or something like that.
37:38They're doing this kind of work, an asset that I don't dare forget.
37:41He's looking nice, this little T-Rex, this little two-year-old.
37:46But with limited fossil remains, the reconstruction has room for creative license.
37:51So can you draw me another baby T-Rex, based on the same evidence, but taking it off in a bit of a different direction?
37:59Let's do the same thing. We have our head.
38:03There's a lot of evidence that some of them had feathers, and that maybe some of them, when they were young,
38:11would have had some sort of downy covering that would have left in adulthood,
38:18so that it would have been shedded before they were fully grown.
38:22This little baby's looking extraordinarily bird-like and has really long legs.
38:25Yeah.
38:26Is this a reasonable interpretation?
38:29There's nothing that says that it can't be this way.
38:32Right. They're fantastic. It's the same creature, but they're very legs.
38:36It's quite extraordinary in this one.
38:38And I love the feathers. I mean, that just immediately makes it look like a completely different creature.
38:43It shows you that there's quite a bit of room for artistic manoeuvre, I think, in these reconstructions.
38:48Yes. Definitely. Definitely.
38:49The questions about Luis's vessels, some scientists have actually questioned whether the bones might belong to a different species of dinosaur entirely.
39:00Something like a T-Rex, but much smaller.
39:03You're presenting a mounted skeleton of this baby T-Rex, and this is the first baby T-Rex that's been found and has been put on display.
39:14How can you be sure that it is indeed a T-Rex, if it's a baby, because bones change as juveniles turn into adults?
39:21You can read the characteristics of the bone tissue, and that can tell you if the animal is a full-grown individual or if it's a baby or a very young individual.
39:34So we know that perhaps in future discoveries may prove that there was another species of Tyrannosaur that essentially lived together with T-Rex,
39:45and that maybe this is a baby of that particular species. But at the moment, with the information that we have, it seems that the most reasonable hypothesis is to say that this one represents a baby of a Tyrannosaurus Rex.
40:02I think that's actually quite brave to put something like a baby T-Rex in this exhibition as a mounted skeleton, because there's nothing to compare it with.
40:09It is our responsibility to make sure that people understand that things are not written in stone, and our scientific conclusions change as we gather more evidence.
40:24Back in New Jersey, the T-Rex's are nearly complete, and Luis has come to inspect them.
40:30This is phenomenal. It looks awesome. It's just fantastic. Really fantastic.
40:39Is everything you thought it would be?
40:41Better. Better. Better. Better.
40:44It's hard to describe, but I feel that it's very dynamic, you know?
40:50We brought the right-hand foot over the center line quite a bit.
40:54Yeah, I can see that.
40:55It's worth with the turning.
40:56I can see that.
40:58There's quite a bit of movement.
41:00Yeah.
41:01I'm glad that you like it, Luis.
41:03I think it's phenomenal.
41:10But it's not completely finished.
41:15Paul and his team need Luis's advice on a couple of issues.
41:19There are several unknowns, and a complete tail has never been found.
41:26So, on the older drawings that we have, there's maybe 53 tail vertebra.
41:32The newer thinking is, is there's close to 43.
41:35Paleontology mostly is a soft science.
41:38So, the theories change with new evidence that is found.
41:41One of the big questions about T-Rex is what its surprisingly short arms were used for.
41:48They might have been used to hold onto prey or to push the body up from a sitting position.
41:53No one knows.
41:55And that's partly because each arm is anchored to the body by the shoulder blade or scapula.
41:59And there's no easy way of telling exactly where that sat.
42:04With the scapula, I've seen they've gone up closer to the vertebra and the backbone.
42:11I've also seen where they're lowered, almost to where the belly is.
42:14There's parts of the front end of the scapula, the coracoids.
42:18And some people think they go together this much, and some people think they go together this much.
42:22But that all has to do with how everything hangs in the front end of this, and also how the hands were used.
42:29Those arms are just about the same size as a human arm.
42:33The difficulty in placing the scapula on Thomas is compounded by the fact that the bones were distorted over the millions of years that they spent buried underground.
42:42They're flattened, and they don't really have the curvature that they must have had when the animal was alive.
42:52Therefore, it's really difficult to fit them on the sides of the rib cage.
42:59I guess that that's the nature of the beast.
43:02We're going to have to find a compromise, and we'll live with it.
43:04Back in L.A., there are two months to go before the exhibition opens. The three T-Rexes are now installed.
43:19Oh, this is a bit different. There are dinosaurs here.
43:22Now, these guys I recognised.
43:25So this is your famous Thomas. Can we get up here?
43:29Sure. Absolutely.
43:30Oh, face to face with a baby T-Rex.
43:35With three T-Rexes of different ages on one platform, it's possible for the first time ever to get an understanding of the entire life cycle of this legend of the dinosaur kingdom.
43:46So having a series of juvenile skeletons like this gives you insights into the way that dinosaurs grew?
43:52Absolutely. The dinosaurs had growth spurts.
43:55So this animal is estimated to have died at the age of two.
44:00Right.
44:01And this one here is estimated to have died at the age of 13.
44:06There's, you know, there's a size discrepancy here, but they're also 11 years apart.
44:12Yet this animal is only four years older than this one, yet is enormously bigger than this one.
44:22What this is telling you is that between 13 and 17, they were able to add about 1500 pounds. That's what 750 kilograms a year.
44:36Wow. And when you see the two skeletons close to each other like that, you really get a kind of physical impression of that.
44:43Although Thomas towers over the younger T-Rexes, even he wasn't fully grown. But at about 17 years old, he was already 11 meters long and over three tons in weight.
44:55So this is a juvenile, this enormous skeleton.
44:59Indeed. This is an animal that probably died at the age of 17, so rather young.
45:04So still a teenager.
45:05You can tell that it's a juvenile not only based on the histology, on the bone tissue that for which we have studies of it, but also because there are many bones that would fuse when the animal was a full grown that have not yet been fused.
45:23One of them is here, the calculator.
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