0:00:08 > 0:00:14I'm here in Patagonia in the southern part of South America because,
0:00:14 > 0:00:19a few years ago, a man looking for one of his lost sheep found
0:00:19 > 0:00:23a simply gigantic bone sticking out of a rock -
0:00:23 > 0:00:26a bone that was going to astonish science.
0:00:28 > 0:00:32That first bone led to the discovery of over 200 others.
0:00:36 > 0:00:43They were all huge - so big that they could only have come from a dinosaur.
0:00:43 > 0:00:46And what a dinosaur it would turn out to be!
0:00:48 > 0:00:51One that seems to defy the laws of nature.
0:00:53 > 0:00:57These bones are part of a skeleton that has remained hidden
0:00:57 > 0:01:01and marvellously preserved for 100 million years.
0:01:05 > 0:01:08'An international team of scientists assembled to try
0:01:08 > 0:01:11'and work out what sort of dinosaur it belonged to.'
0:01:14 > 0:01:16It's like a palaeontological crime scene!
0:01:18 > 0:01:21Each bone is an important piece of evidence that can give us
0:01:21 > 0:01:25information as to what the living creature was actually like.
0:01:25 > 0:01:29We'll use the latest forensic technology,
0:01:29 > 0:01:33we'll compare it with how giant animals live today
0:01:33 > 0:01:38and we'll build a full-size skeleton of this stupendous creature.
0:01:41 > 0:01:45And we will try and work out in detail what it looked like
0:01:45 > 0:01:46when it was alive.
0:01:51 > 0:01:52HE GASPS
0:01:52 > 0:01:55Absolutely amazing!
0:01:56 > 0:01:59Could it really have been the biggest animal
0:01:59 > 0:02:00ever to walk the Earth?
0:02:20 > 0:02:23Patagonia in southern Argentina.
0:02:26 > 0:02:31Like many detective stories, this one began by chance.
0:02:33 > 0:02:36A shepherd stumbled across the tip of a huge bone
0:02:36 > 0:02:38poking out of the ground.
0:02:40 > 0:02:41HORSE SNORTS
0:02:46 > 0:02:50Experts from Patagonia's premier palaeontological museum
0:02:50 > 0:02:53confirmed it was part of a dinosaur.
0:02:53 > 0:02:54THEY SPEAK SPANISH
0:02:59 > 0:03:03But they didn't realise at the time what a truly extraordinary one
0:03:03 > 0:03:04it would prove to be.
0:03:10 > 0:03:13Dinosaurs of many kinds roamed all over these lands
0:03:13 > 0:03:16in the southern end of South America
0:03:16 > 0:03:19during what's known as the Cretaceous period,
0:03:19 > 0:03:23between 66 and 145 million years ago.
0:03:25 > 0:03:29The largest were plant-eaters known as sauropods.
0:03:29 > 0:03:33And the largest of them were the titanosaurs.
0:03:35 > 0:03:39Giant titanosaur bones are comparatively rare
0:03:39 > 0:03:42so very little is known about these dinosaurs.
0:03:46 > 0:03:49This new discovery could change all that.
0:03:55 > 0:04:01'Like many people, young and old, I'm fascinated by dinosaurs,
0:04:01 > 0:04:04'so the chance to join this investigation
0:04:04 > 0:04:06'is just too good an opportunity to miss.'
0:04:06 > 0:04:09Oh, I'd love to have a go!
0:04:09 > 0:04:10HE LAUGHS
0:04:10 > 0:04:12I'm sure they'd let you.
0:04:12 > 0:04:13HE LAUGHS
0:04:13 > 0:04:16'Of course, it's the giants in particular that capture
0:04:16 > 0:04:17'the imagination.'
0:04:20 > 0:04:22The first sauropods to appear on Earth
0:04:22 > 0:04:24were comparatively small creatures.
0:04:24 > 0:04:29This is the cast of the thigh bone of one of them.
0:04:29 > 0:04:32It's not even as big as my thigh bone.
0:04:32 > 0:04:39But after about 20 million years, some had become pretty big.
0:04:39 > 0:04:43This is a thigh bone from one of those creatures.
0:04:43 > 0:04:44But then, after that...
0:04:46 > 0:04:51..our giant appeared. This is its thigh bone.
0:04:53 > 0:04:55It's the largest ever found.
0:05:04 > 0:05:08Coming across such a bone in your back yard must be quite a shock.
0:05:08 > 0:05:11Just ask farm owner Alba Maio.
0:05:14 > 0:05:16HENS CLUCK
0:05:16 > 0:05:18TRANSLATION:
0:05:20 > 0:05:21SHE LAUGHS
0:05:21 > 0:05:25TRANSLATION:
0:05:35 > 0:05:39Before long, a whole team of fossil-hunting scientists
0:05:39 > 0:05:41arrives and starts work.
0:05:53 > 0:05:58The thighbone proves to be eight feet, 2.4 metres long.
0:06:05 > 0:06:10It's preserved in extraordinary detail, and detail will be
0:06:10 > 0:06:13critical to the forensic examination that will follow.
0:06:24 > 0:06:29The research team soon turn the site into a vast quarry.
0:06:38 > 0:06:42It proves to be one of the biggest dinosaur finds of the century.
0:06:45 > 0:06:49Bone after bone emerge from the rocks.
0:06:49 > 0:06:52THEY LAUGH
0:06:54 > 0:06:57We just found another bone right here.
0:06:57 > 0:06:59We weren't expecting it at all.
0:06:59 > 0:07:01We just start digging and find it.
0:07:04 > 0:07:06Until recently, giant titanosaurs
0:07:06 > 0:07:09have only been known from a dozen bones
0:07:09 > 0:07:14and our team have already found more than ten times as many.
0:07:20 > 0:07:23Dr Diego Pol is the chief palaeontologist
0:07:23 > 0:07:26leading the investigation.
0:07:26 > 0:07:28If you really want to know
0:07:28 > 0:07:32what a really gigantic dinosaur looked like, this quarry here
0:07:32 > 0:07:34has the potential to answer that question
0:07:34 > 0:07:37and that's really exciting for us.
0:07:38 > 0:07:39It's really impressive.
0:07:39 > 0:07:44When you stand by one of these bones, you really feel tiny.
0:07:45 > 0:07:49With so much new evidence, there is a chance of discovering
0:07:49 > 0:07:54all kinds of new facts about the mysterious titanosaurs.
0:07:56 > 0:07:59It's like a palaeontological crime scene.
0:07:59 > 0:08:01It's a really unique thing
0:08:01 > 0:08:04that you will not find anywhere else in the world.
0:08:07 > 0:08:09Patagonia's harsh weather
0:08:09 > 0:08:12makes uncovering the fossils exhausting,
0:08:12 > 0:08:17but it also endangers the newly-exposed fossils.
0:08:19 > 0:08:21THUNDER RUMBLES
0:08:21 > 0:08:22A lot of damage from the rain
0:08:22 > 0:08:26so we need to protect the bones that are at risk.
0:08:26 > 0:08:30I'm really concerned that this already has some cracks.
0:08:31 > 0:08:33If the bones aren't protected,
0:08:33 > 0:08:36tiny details on their surface could be lost.
0:08:42 > 0:08:46To protect the bones, they're covered with, of all things,
0:08:46 > 0:08:50wet toilet paper and plaster of Paris.
0:08:50 > 0:08:54It's like putting a plaster cast on a broken leg.
0:08:57 > 0:09:00There's a rush to get them back to the museum
0:09:00 > 0:09:03to begin examining them in minute detail.
0:09:08 > 0:09:12A new road has been specially built to enable them
0:09:12 > 0:09:15to be transported without too much jolting.
0:09:19 > 0:09:24Once at the museum laboratory, the detailed detective work begins.
0:09:32 > 0:09:36It's a chance to start putting flesh on bones.
0:09:36 > 0:09:40Some really big muscle was going in here.
0:09:40 > 0:09:43This animal was so big that it certainly needed
0:09:43 > 0:09:47really powerful muscles and very strong attachments
0:09:47 > 0:09:49into the bones.
0:09:59 > 0:10:02This is a giant vertebra, one of the bones of the spine,
0:10:02 > 0:10:06and it's a very important find.
0:10:06 > 0:10:09That's because it's likely to provide crucial evidence
0:10:09 > 0:10:12for identifying the species of our dinosaur.
0:10:18 > 0:10:20Despite weighing up to half a tonne,
0:10:20 > 0:10:22these fossils are surprisingly fragile.
0:10:27 > 0:10:29It's all rather nerve-racking.
0:10:30 > 0:10:34One bone like this has already cracked in half without warning.
0:10:39 > 0:10:40Bravo!
0:10:50 > 0:10:53THEY LAUGH
0:10:53 > 0:10:56And so this is the position as it was in life
0:10:56 > 0:10:59with the centre of the backbone there,
0:10:59 > 0:11:01then this is the crest on the top.
0:11:01 > 0:11:04Right, right, and this belongs to the middle part of the thorax.
0:11:04 > 0:11:08- Right about here. - About that.- Yeah, yeah.
0:11:08 > 0:11:11'Many more weeks of detailed examination
0:11:11 > 0:11:14'will be needed before the backbones reveal all their secrets.'
0:11:17 > 0:11:21Surprisingly, perhaps, one of the first things
0:11:21 > 0:11:26the team was able to deduce about our titanosaur is its weight.
0:11:27 > 0:11:30That's because, after finding the thigh bone,
0:11:30 > 0:11:35they discover another huge bone from the front leg - a humerus.
0:11:42 > 0:11:45By measuring the circumference of each of these leg bones,
0:11:45 > 0:11:48it's possible to estimate how much weight they could support.
0:11:48 > 0:11:51Let's see how much.
0:11:52 > 0:11:54We'll measure this.
0:11:58 > 0:12:02- 79.- 79? Wow!
0:12:02 > 0:12:05I'm not sure how that translates to body weight.
0:12:05 > 0:12:09- Yeah, around 70 tonnes or even more, probably.- Wow!
0:12:09 > 0:12:11That's really big.
0:12:11 > 0:12:13It's amazing.
0:12:14 > 0:12:20That evening, Dr Jose Luis Carballido checks his calculations.
0:12:40 > 0:12:44Until now, Argentinosaurus was the heaviest known dinosaur.
0:12:44 > 0:12:47Ours already looks bigger.
0:12:55 > 0:13:00Could this mean it was the largest animal ever to walk the Earth?
0:13:00 > 0:13:04Could it also be a new species?
0:13:04 > 0:13:07We can't be sure...yet.
0:13:09 > 0:13:12The rocks of Patagonia, so bare of vegetation,
0:13:12 > 0:13:18also contain astonishing evidence of how titanosaurs began their lives.
0:13:21 > 0:13:24I've now come nearly 500 miles north
0:13:24 > 0:13:27from our Patagonian dinosaur excavation
0:13:27 > 0:13:29to a place called Auca Mahuevo.
0:13:29 > 0:13:35This is the largest dinosaur nesting ground yet discovered.
0:13:35 > 0:13:41The remains of their eggs and their nests are wherever I look.
0:13:41 > 0:13:44In fact, it's quite difficult for me
0:13:44 > 0:13:48to take a step without walking on a dinosaur eggshell.
0:13:55 > 0:13:56Over thousands of years,
0:13:56 > 0:13:59the wind and the rain have cleared away the soft rock
0:13:59 > 0:14:02that once enclosed these fragments
0:14:02 > 0:14:08and they can tell us quite a lot about how titanosaurs reproduced.
0:14:09 > 0:14:13Careful excavation has shown that these dinosaurs
0:14:13 > 0:14:18laid eggs in clutches of up to 30 or 40 at a time.
0:14:18 > 0:14:21They would have looked rather like these replicas
0:14:21 > 0:14:23because they lay on the surface of the ground,
0:14:23 > 0:14:26not covered by soil, but in a shallow depression.
0:14:26 > 0:14:28Sometimes, though,
0:14:28 > 0:14:31remains of vegetation have been found in some nests,
0:14:31 > 0:14:35which suggests that the dinosaurs might have used rotting leaves
0:14:35 > 0:14:37to help with the incubation.
0:14:37 > 0:14:41The dinosaur that laid these eggs here were medium-sized.
0:14:41 > 0:14:44Our dinosaur that we're excavating,
0:14:44 > 0:14:47probably laid eggs as big as that.
0:14:48 > 0:14:53I'm shown around by Dr Luis Chiappe who, with his team,
0:14:53 > 0:14:55discovered this remarkable site.
0:14:56 > 0:15:00Dinosaur eggs here were laid on an old river plain.
0:15:01 > 0:15:04Then the river flooded and covered the unhatched eggs,
0:15:04 > 0:15:06preserving them in mud.
0:15:07 > 0:15:10You see, you know, many eggs...
0:15:10 > 0:15:12There.
0:15:12 > 0:15:15..for kilometres and kilometres. Here's a nice one.
0:15:15 > 0:15:17- Oh, that's a huge piece!- Yup.
0:15:20 > 0:15:24- And this is the actual surface of the egg?- Yes.
0:15:24 > 0:15:25Astounding.
0:15:27 > 0:15:30Do you suppose they could have been coloured like birds' eggs?
0:15:30 > 0:15:32They may. Maybe they were off-white.
0:15:32 > 0:15:35- We can't tell really.- Yeah.
0:15:35 > 0:15:38Well, we can see all the tiny pores on the surface.
0:15:38 > 0:15:39And the texture.
0:15:39 > 0:15:42Yeah. What a beautiful piece.
0:15:42 > 0:15:45You must admit it's pretty romantic.
0:15:45 > 0:15:47THEY LAUGH
0:15:47 > 0:15:48I think it's incredible.
0:15:48 > 0:15:50I think it's absolutely extraordinary
0:15:50 > 0:15:52and I must put it back where I found it.
0:15:52 > 0:15:53Thank you.
0:15:57 > 0:16:01The fragments could tell us quite a lot about how the dinosaurs nested.
0:16:02 > 0:16:05But some, amazingly, can do even more than that.
0:16:11 > 0:16:15All these examples have something quite special.
0:16:15 > 0:16:19This one is my favourite.
0:16:19 > 0:16:26And what you can see is a very large patch of baby dinosaur skin.
0:16:27 > 0:16:29How wonderful!
0:16:29 > 0:16:30It's extraordinary.
0:16:30 > 0:16:34- And this is not just an impression, this is the mineralised skin.- It is.
0:16:34 > 0:16:36Yeah.
0:16:36 > 0:16:38Astounding.
0:16:38 > 0:16:41The eggs were not just preserving the bones,
0:16:41 > 0:16:43- they were also preserving the skin of these babies.- Yeah.
0:16:45 > 0:16:47This was just on the surface.
0:16:47 > 0:16:50I remember picking this up and brushing it a little bit
0:16:50 > 0:16:52and then using my hand lens
0:16:52 > 0:16:58and looking at this exact patch of skin and I realised that
0:16:58 > 0:17:03we had found something that no person had ever seen before.
0:17:03 > 0:17:08- You are the first human being ever to see a baby dinosaur's skin.- Yes.
0:17:08 > 0:17:10It was just an amazing...
0:17:10 > 0:17:13amazing moment.
0:17:13 > 0:17:15It must have been very close to hatching.
0:17:15 > 0:17:19- It's almost complete, this thing. - Yes, that's what we believe.
0:17:19 > 0:17:21And then a flood...
0:17:21 > 0:17:23Killed them all.
0:17:23 > 0:17:26- Unfortunately for them, good for us.- Yes.
0:17:29 > 0:17:33Luis Chiappe has dozens of complete eggs in his museum and
0:17:33 > 0:17:38he allows me to examine some of his most precious specimens for myself.
0:17:42 > 0:17:44There are many other remarkable things
0:17:44 > 0:17:46in these astonishing time capsules.
0:17:46 > 0:17:51This one has got, perfectly clearly, the limb bones.
0:17:54 > 0:17:56Here is a skull.
0:17:56 > 0:17:59That's the orbit of the eye,
0:17:59 > 0:18:02there's the lower jaw, there's the snout.
0:18:05 > 0:18:07This one also has a skull,
0:18:07 > 0:18:13but on the tip of the snout you can see a little spike which is like the
0:18:13 > 0:18:18egg tooth that a bird embryo has to help it crack itself out of a shell.
0:18:22 > 0:18:26And here is a replica of what the complete,
0:18:26 > 0:18:29un-crushed shell must have looked like.
0:18:32 > 0:18:34With all these details,
0:18:34 > 0:18:38it is possible to imagine how a baby titanosaur entered the world.
0:18:39 > 0:18:40BABY SQUEAKS
0:18:49 > 0:18:52To get an idea of how these youngsters might have lived,
0:18:52 > 0:18:57we can compare them with their closest living relatives - birds.
0:19:00 > 0:19:04Rather like baby ostriches, a young titanosaur
0:19:04 > 0:19:08would have been able to walk soon after hatching.
0:19:12 > 0:19:15They may well have gathered into groups to give some safety
0:19:15 > 0:19:18from predators, as young ostriches do.
0:19:32 > 0:19:36Microscopic analysis of dinosaur leg bones show rings,
0:19:36 > 0:19:38rather like tree rings,
0:19:38 > 0:19:41and these indicate that titanosaurs grew very swiftly
0:19:41 > 0:19:43early in their lives
0:19:43 > 0:19:47and they could have lived for some 50 years,
0:19:47 > 0:19:49plenty of time to become enormous.
0:19:51 > 0:19:54The team now has 150 bones of our titanosaur,
0:19:54 > 0:19:57enough to get an idea, not only of its weight,
0:19:57 > 0:19:59but also its height and length.
0:20:00 > 0:20:04Now, the plan is to build a life-size reproduction
0:20:04 > 0:20:05of the complete skeleton.
0:20:22 > 0:20:26It's a challenge to find a place big enough to house an animal that's
0:20:26 > 0:20:31four times longer than a London bus and nearly twice its height.
0:20:31 > 0:20:35But Diego thinks he's found one. It's an old wool warehouse.
0:20:40 > 0:20:43One, two, three, four,
0:20:43 > 0:20:47five, six, seven...
0:20:47 > 0:20:50We have been looking for a place that is big enough
0:20:50 > 0:20:52to fit our dinosaur.
0:20:55 > 0:20:57This seems to be it.
0:20:57 > 0:20:59This is a warehouse that we could use,
0:20:59 > 0:21:02not only in terms of the length, this is 70 metres long,
0:21:02 > 0:21:05but also it's very important in terms of the height.
0:21:05 > 0:21:08So we need a place not only long, but really high.
0:21:09 > 0:21:11It really needs a little bit of decoration,
0:21:11 > 0:21:13but I think it will do it.
0:21:13 > 0:21:14It's going to be awesome!
0:21:18 > 0:21:20Putting the skeleton together will help us
0:21:20 > 0:21:23understand the particular challenges of being such a giant.
0:21:30 > 0:21:34So, next, an international team of skeleton builders arrive
0:21:34 > 0:21:39to scan the bones ready to make a 3-D computer model of each of them.
0:21:47 > 0:21:523-D scanning, accurate to 0.01 of a millimetre,
0:21:52 > 0:21:57allows images of the bones to be placed in a virtual reality world
0:21:57 > 0:22:01so that they can now be examined from all points of view
0:22:01 > 0:22:03without needing eight people to lift them.
0:22:07 > 0:22:10One of the mysteries surrounding our dinosaur is,
0:22:10 > 0:22:14how could an animal as big as it was actually move about?
0:22:17 > 0:22:19The computer data allows us
0:22:19 > 0:22:22to put our dinosaur leg bones together in 3-D
0:22:22 > 0:22:27and then compare the arrangement with what we know about living animals.
0:22:38 > 0:22:41Elephants are the largest land animal alive today.
0:22:45 > 0:22:50They, like titanosaurs, have to move their massive bodies around
0:22:50 > 0:22:53without their bones shattering under the enormous weight.
0:23:00 > 0:23:03I've come to meet Professor John Hutchinson
0:23:03 > 0:23:06here at ZSL Whipsnade Zoo.
0:23:07 > 0:23:10He's studied elephants for many years and has joined the team
0:23:10 > 0:23:15that's investigating the internal workings of our titanosaur.
0:23:15 > 0:23:18We have about a one-metre long pressure sensitive mat out there
0:23:18 > 0:23:21with several thousand sensors in it and it's telling us, in very
0:23:21 > 0:23:25high resolution, what the pressure on an elephant's foot is like.
0:23:26 > 0:23:29We can see on the elephant's foot here...
0:23:29 > 0:23:31- Here she goes...- Oh, yeah! Great.
0:23:31 > 0:23:33- Oh, that was a perfect one! - Bull's-eye!
0:23:34 > 0:23:36The pressure hits the ground,
0:23:36 > 0:23:40rolls over and then pushes off with its toenails.
0:23:41 > 0:23:46So we can see there are some hot colours, or reds and oranges,
0:23:46 > 0:23:50on the toenails of Melvin's foot, indicating high pressure.
0:23:50 > 0:23:54And then some cooler colours back towards the heel pad
0:23:54 > 0:23:57in the greens and light blue.
0:23:57 > 0:23:59That's low pressure.
0:23:59 > 0:24:03So elephants are supporting most of their weight on their toenails.
0:24:03 > 0:24:06That pressure gets transmitted up to their toe bones
0:24:06 > 0:24:10and then up to their wrists and ankles and so forth.
0:24:12 > 0:24:17John's analysis suggests that our titanosaur's legs,
0:24:17 > 0:24:19like those of an elephant,
0:24:19 > 0:24:23were placed vertically beneath the body like strong, massive columns.
0:24:26 > 0:24:29This arrangement transmits the weight to the toes
0:24:29 > 0:24:34and then spreads the force, using fatty pads in the back feet,
0:24:34 > 0:24:36as shock absorbers.
0:24:38 > 0:24:42But our titanosaur had one other adaptation to help them walk -
0:24:42 > 0:24:43one that elephants lack.
0:24:48 > 0:24:51A clue to this can be seen on the giant thighbone.
0:24:53 > 0:24:55- How's it going?- Good, good.
0:24:55 > 0:24:59Ben Garrod specialises in reconstructing skeletons
0:24:59 > 0:25:03and he's joining the team to look at the bones in detail.
0:25:04 > 0:25:08Marks on them show clearly where the muscles were attached.
0:25:09 > 0:25:12- That's halfway down the femur, isn't it, that big lump there...- Yes.
0:25:12 > 0:25:15..for these massive muscle and, I guess, tendon attachments?
0:25:16 > 0:25:20This lump is where a huge muscle was attached to the femur.
0:25:22 > 0:25:24The other end of this muscle was connected to bones
0:25:24 > 0:25:26like these in the tail.
0:25:27 > 0:25:30It's this connection that helped our dinosaur to walk.
0:25:32 > 0:25:35They've got so much strength and so much rigidity up there.
0:25:35 > 0:25:39They actually used their tails to help move, to help their propulsion.
0:25:39 > 0:25:43- So they had massive muscles and tendons from...- Help...?
0:25:43 > 0:25:46Yes, so the movement of the tail actually pulled the hind legs
0:25:46 > 0:25:48backwards and then raised them forwards.
0:25:48 > 0:25:49Oh, I see.
0:25:51 > 0:25:52I must try that sometime!
0:25:52 > 0:25:54LAUGHTER
0:25:57 > 0:26:01The largest lizard alive today, the Komodo dragon,
0:26:01 > 0:26:04has a similar adaptation.
0:26:05 > 0:26:09The swing of their tail helps their back legs move more efficiently.
0:26:14 > 0:26:17Of course, our dinosaur was different,
0:26:17 > 0:26:19not least because it weighed over 500 times more.
0:26:21 > 0:26:25And that makes John Hutchinson suspect that it would have
0:26:25 > 0:26:27had to deal with another problem -
0:26:27 > 0:26:31one also faced by passengers on long-haul flights.
0:26:32 > 0:26:36Pressure in the legs of big animals is a really big problem.
0:26:36 > 0:26:41If blood stays down there too long, it's going to pool and clot.
0:26:41 > 0:26:44Much like airline socks that humans use,
0:26:44 > 0:26:49large animals, again and again, have evolved very thick elastic skin
0:26:49 > 0:26:54around their lower limb that helps to keep that pressure very high.
0:26:54 > 0:26:55Actually, I can empathise.
0:26:55 > 0:26:59I have to wear those same kind of stockings to get my blood
0:26:59 > 0:27:01back up my long legs!
0:27:02 > 0:27:04'Time to thank our helpful elephant.'
0:27:04 > 0:27:06You're a lovely thing. Yes, you...
0:27:06 > 0:27:09Oh, you want one! OK, in you go.
0:27:11 > 0:27:13Thanks. Thanks, pal.
0:27:14 > 0:27:15That's all I've got!
0:27:18 > 0:27:22A giant animal like an elephant also needs a huge heart
0:27:22 > 0:27:24to pump blood around its body.
0:27:24 > 0:27:26And so did our titanosaur.
0:27:42 > 0:27:45Its heart must have been immense.
0:27:48 > 0:27:50From our new, detailed knowledge of the skeleton,
0:27:50 > 0:27:53John Hutchinson has calculated that it was
0:27:53 > 0:27:56more than six feet in circumference.
0:27:56 > 0:27:57THUMPING HEARTBEAT
0:28:02 > 0:28:06It probably weighed 230 kilos
0:28:06 > 0:28:11and would have had to shift 90 litres of blood with a single beat.
0:28:11 > 0:28:12There's one!
0:28:16 > 0:28:20And it would have had to repeat that beat every five seconds.
0:28:20 > 0:28:22HEART THUMPS
0:28:22 > 0:28:23There it goes again.
0:28:27 > 0:28:30Weighing more than three grown men,
0:28:30 > 0:28:32it would have been extraordinarily powerful.
0:28:38 > 0:28:43And in order to pump blood around the body at high pressure
0:28:43 > 0:28:47and then into the delicate lungs at a lower pressure,
0:28:47 > 0:28:52it's thought that our titanosaur's heart had four chambers,
0:28:52 > 0:28:54more like that of a bird than a reptile.
0:28:59 > 0:29:05So, a powerful heart pumped the blood to the extremities of the body,
0:29:05 > 0:29:07but how did the blood get back?
0:29:11 > 0:29:12As in an elephant,
0:29:12 > 0:29:17a combination of fatty footpads and tight skin
0:29:17 > 0:29:19are thought to have forced the blood from its legs...
0:29:21 > 0:29:23..all the way back to its heart.
0:29:37 > 0:29:40Toronto, Canada,
0:29:40 > 0:29:43and the world's biggest dinosaur-making factory.
0:29:51 > 0:29:56The team is building a life-size skeleton of this vast creature
0:29:56 > 0:30:01to be unveiled in Diego's warehouse in Argentina in six months' time.
0:30:04 > 0:30:08First, they have to turn all the information from the 3-D scans
0:30:08 > 0:30:10into each individual bone.
0:30:14 > 0:30:18State-of-the-art robots carve moulds from polystyrene
0:30:18 > 0:30:20so that the bones can be cast in fibreglass.
0:30:37 > 0:30:42Up until now, the fossil bones have been the main focus of the dig,
0:30:42 > 0:30:44but the rock that surrounds the fossils
0:30:44 > 0:30:46also holds important information.
0:30:47 > 0:30:52The nature of the layers of rock in which these fossils lie can tell us
0:30:52 > 0:30:57a great deal about how they got to be where they are, and how old they are.
0:30:58 > 0:31:01Some of these layers are volcanic ash,
0:31:01 > 0:31:04which must have come from a volcano erupting every now and then
0:31:04 > 0:31:07somewhere in the neighbourhood.
0:31:07 > 0:31:09DRILLS TAPPING
0:31:11 > 0:31:15And this ash around the bones can tell us how old the fossils are.
0:31:17 > 0:31:19Scientists worked out that all these fossils
0:31:19 > 0:31:22dated from the Cretaceous period,
0:31:22 > 0:31:24but better than that,
0:31:24 > 0:31:31they dated them precisely to 101.6 million years old.
0:31:38 > 0:31:42By a detailed forensic examination
0:31:42 > 0:31:45and comparisons with living creatures,
0:31:45 > 0:31:50the team have deduced a great deal about the life of our titanosaur.
0:31:53 > 0:31:56We now know when it lived,
0:31:56 > 0:31:58how big it was,
0:31:58 > 0:32:00how it moved,
0:32:00 > 0:32:03and what its young might have looked like.
0:32:03 > 0:32:06We've even calculated its heart rate.
0:32:13 > 0:32:15In an investigation of this scale,
0:32:15 > 0:32:18sometimes the most important information comes
0:32:18 > 0:32:22not from the most eye-catching evidence,
0:32:22 > 0:32:24but from quite tiny details.
0:32:28 > 0:32:33Here is something that I really hoped the excavation was going to find.
0:32:36 > 0:32:37It's a tooth.
0:32:39 > 0:32:44And it's tiny compared with the size of the huge animals
0:32:44 > 0:32:45from which it came.
0:32:46 > 0:32:51Teeth can tell you a huge amount about an animal.
0:32:51 > 0:32:53And if you look at the tip,
0:32:53 > 0:32:59you can see that it has been worn into two faucets on either side.
0:32:59 > 0:33:02And that tells us that this tooth
0:33:02 > 0:33:07engaged with the teeth on the other side in an alternate way like that,
0:33:07 > 0:33:11not head-on, but one on either side.
0:33:11 > 0:33:13So this animal, like a pair of scissors,
0:33:13 > 0:33:18just nipped off the vegetation on which it was feeding.
0:33:18 > 0:33:20Enormous though it was,
0:33:20 > 0:33:22just nipped off little leaves,
0:33:22 > 0:33:27and here are fossils of some of the different kinds of plants
0:33:27 > 0:33:28on which it might have fed.
0:33:30 > 0:33:31Cycads,
0:33:31 > 0:33:33ferns,
0:33:33 > 0:33:34and conifers.
0:33:44 > 0:33:46One thing these plants have in common
0:33:46 > 0:33:50is that they're all very fibrous and hard to digest.
0:33:51 > 0:33:55To get enough nutrients from such poor quality foods,
0:33:55 > 0:33:59our titanosaur would have had to eat them in vast quantities.
0:34:03 > 0:34:08A descendent of one of these plants still grows in Patagonia today.
0:34:12 > 0:34:14200 million years ago,
0:34:14 > 0:34:19when South America, Australia and Antarctica were all joined together
0:34:19 > 0:34:22to form a supercontinent called Gondwana,
0:34:22 > 0:34:26a particular kind of vegetation was dominant.
0:34:26 > 0:34:27They were conifers.
0:34:28 > 0:34:31They continued to survive to 100 million years ago,
0:34:31 > 0:34:34when our titanosaurs were roaming the land,
0:34:34 > 0:34:37and a few still survive today.
0:34:37 > 0:34:41Here in the foothills of the Andes is one of them.
0:34:41 > 0:34:45The monkey puzzle tree, called araucaria.
0:34:49 > 0:34:53Trees like araucaria show that the dinosaurs
0:34:53 > 0:34:55must have had another problem.
0:34:56 > 0:34:59These conifers, apart from being poor-quality fodder,
0:34:59 > 0:35:03can grow to over 130 feet in height.
0:35:05 > 0:35:08They would have been out of reach for many animals
0:35:08 > 0:35:10but not our titanosaur.
0:35:15 > 0:35:17Here, boys, come on.
0:35:21 > 0:35:26It's pretty clear why a long neck is useful for a land-living animal.
0:35:27 > 0:35:32It enables it to reach vegetation which is growing high up
0:35:32 > 0:35:36at the top of trees that other ground-based animals couldn't reach,
0:35:36 > 0:35:40and it must have been much the same for titanosaurs,
0:35:40 > 0:35:44except we know from the fossils the titanosaur's neck was
0:35:44 > 0:35:46very, very much longer.
0:35:47 > 0:35:52And that enabled it to sweep its head in a great wide arc
0:35:52 > 0:35:56and even to reach between two tree trunks that happened to be
0:35:56 > 0:35:59growing close together to get other vegetation.
0:36:00 > 0:36:01What about that?
0:36:04 > 0:36:08This enormous reach would have saved our titanosaur a lot of energy.
0:36:09 > 0:36:13It only needed to move its neck to feed, not its whole body.
0:36:17 > 0:36:20But how did it eat enough of this poor-quality food to survive?
0:36:22 > 0:36:25Elephants face a similar challenge today.
0:36:26 > 0:36:31An elephant can collect and chew about 130 kilos.
0:36:31 > 0:36:34That's 300 pounds of vegetation in a day.
0:36:35 > 0:36:39But our titanosaur could have eaten five times that amount.
0:36:41 > 0:36:44It's been estimated that a large titanosaur would eat
0:36:44 > 0:36:48enough plant material to fill a skip in a single day.
0:36:49 > 0:36:52So how did they digest it all?
0:36:52 > 0:36:55Elephants solve the problem by giving their food
0:36:55 > 0:36:57long preparatory chews,
0:36:57 > 0:36:59but titanosaurs didn't bother.
0:37:01 > 0:37:05They simply gathered leaves by nipping them off,
0:37:05 > 0:37:07and then swallowing them whole.
0:37:09 > 0:37:11But that in turn would mean that they needed
0:37:11 > 0:37:16a bigger and longer gut to digest all that unchewed food.
0:37:17 > 0:37:19And it might well have taken ten days
0:37:19 > 0:37:22for food to pass through their system.
0:37:24 > 0:37:30A bigger gut needs a bigger body so titanosaurs grew bigger and bigger
0:37:30 > 0:37:34until they approached the limits of what their bones could support.
0:37:44 > 0:37:46Two years after the dig began,
0:37:46 > 0:37:49a strange cargo arrives,
0:37:49 > 0:37:52having made a 7,000 mile journey from Canada.
0:37:59 > 0:38:01Dozens of packing cases later,
0:38:01 > 0:38:05and all the bones are finally in Diego's warehouse.
0:38:14 > 0:38:17Assembling the skeleton can finally begin.
0:38:20 > 0:38:24The 3-D data used to make the skeleton
0:38:24 > 0:38:27has also been used to create a computer model.
0:38:28 > 0:38:30It means I can get a preview
0:38:30 > 0:38:33of what the final skeleton will look like.
0:38:33 > 0:38:36The first thing is these very, very lovely legs.
0:38:36 > 0:38:38If we turn it around, they're very, very column-like.
0:38:38 > 0:38:40Now, this is like elephants
0:38:40 > 0:38:45but interestingly, this titanosaur had slightly splayed legs,
0:38:45 > 0:38:46at an angle of about five degrees,
0:38:46 > 0:38:50and this slight change would have really increased
0:38:50 > 0:38:52the ability to take all that extra weight.
0:38:52 > 0:38:55Can you see the splay because of the joint,
0:38:55 > 0:38:57- or because of the shape of the bone? - A bit of both.
0:38:57 > 0:39:00You can tell from the shape of the bone and from where certain parts
0:39:00 > 0:39:02of the bones form and how they sit,
0:39:02 > 0:39:04and then how the bones fit with one another,
0:39:04 > 0:39:06you can really tell how it would have sat in real life.
0:39:06 > 0:39:10Another thing you can see is a very, very long neck.
0:39:10 > 0:39:14And we've just found out that ours had 15 bones in its neck.
0:39:14 > 0:39:15Interestingly, some of them were
0:39:15 > 0:39:18five or six times longer than they were wide.
0:39:18 > 0:39:21These incredibly long vertebrae, and there's lots of them.
0:39:21 > 0:39:23Why does it have such a long tail?
0:39:24 > 0:39:25Well, a couple of reasons.
0:39:25 > 0:39:28If you've got an animal this big with a neck this long,
0:39:28 > 0:39:30the last thing you want to be is top-heavy.
0:39:30 > 0:39:33And again, research has just shown that
0:39:33 > 0:39:34the centre of gravity in this animal
0:39:34 > 0:39:37was somewhere right in the middle of the chest cavity.
0:39:39 > 0:39:44So the heavy tail counterbalances the exceedingly long neck.
0:39:44 > 0:39:47But judging from the size of the muscle attachments,
0:39:47 > 0:39:50the tail was also immensely strong.
0:39:51 > 0:39:54It would have had huge muscles, from around here
0:39:54 > 0:39:57right down to about a third of the way down the tail,
0:39:57 > 0:39:59somewhere around here.
0:39:59 > 0:40:00So that would be solid flesh?
0:40:00 > 0:40:02Yep, muscle tissue, other tissue,
0:40:02 > 0:40:04ligaments, tendons.
0:40:04 > 0:40:06Do you think they might have fought with it?
0:40:06 > 0:40:07- Possibly.- Thrashing it about?
0:40:07 > 0:40:10It could've been used as a defence mechanism
0:40:10 > 0:40:13so you're walking up to that as a predator, the last thing you want
0:40:13 > 0:40:15- to be is on the receiving end. - Don't put me into it!
0:40:15 > 0:40:17LAUGHTER
0:40:18 > 0:40:19Yeah.
0:40:29 > 0:40:34The long and painstaking examination of the backbone has now borne fruit,
0:40:34 > 0:40:36and Ben has got some important news.
0:40:42 > 0:40:46Now, this is a vertebrae, here, from right high up in the back,
0:40:46 > 0:40:47right near the shoulder blades.
0:40:47 > 0:40:50And the most important thing is this little ridge...
0:40:52 > 0:40:53..that ends in this big lump,
0:40:53 > 0:40:56and this is only found in this particular dinosaur,
0:40:56 > 0:40:59so from that, and a few other physical differences,
0:40:59 > 0:41:02we think we've got a brand-new, exciting species.
0:41:05 > 0:41:08So our titanosaur is not only a giant,
0:41:08 > 0:41:12it is indeed a new species of dinosaur.
0:41:14 > 0:41:18Examining the spinal bones also reveal something about
0:41:18 > 0:41:20how it coped with life as a giant.
0:41:23 > 0:41:26So, this is where the spinal cord would have passed.
0:41:27 > 0:41:31- So, this hole straight through here?- Mm-hm.
0:41:31 > 0:41:32The whole nerve centre, as it were,
0:41:32 > 0:41:35- the cable carrying all the nerves. - From the base of the tail
0:41:35 > 0:41:39- right to the skull.- It's very small. - It is, yeah.- Ours is what?
0:41:39 > 0:41:41About thumb width.
0:41:41 > 0:41:43- So it's not all that much bigger.- No.
0:41:45 > 0:41:48This cord was well over 100 feet long.
0:41:50 > 0:41:54It would have taken about a second for a nerve impulse
0:41:54 > 0:41:56to go from its tail to its brain.
0:41:57 > 0:42:01And what's more, the spine has revealed another surprise.
0:42:02 > 0:42:05It's full of holes, rather like a Swiss cheese.
0:42:08 > 0:42:13The neck bones of titanosaurs contain so many holes and spaces
0:42:13 > 0:42:17that they weighed around 35% less than they would have done
0:42:17 > 0:42:19had they been made of solid bone.
0:42:20 > 0:42:23The leg bones of modern birds are much the same.
0:42:24 > 0:42:28And those spaces serve another very important function.
0:42:28 > 0:42:31They contained air sacs.
0:42:33 > 0:42:37These air sacs were connected with the lungs.
0:42:41 > 0:42:44So what was their function, and how did they work?
0:42:44 > 0:42:47They occupied much of the chest,
0:42:47 > 0:42:49and ran along the whole length of the body,
0:42:49 > 0:42:51along the backbone,
0:42:51 > 0:42:55to the very long neck, and then along to the head.
0:42:58 > 0:43:03It's thought the balloon-like sacs had thin but strong membranes.
0:43:06 > 0:43:08These sacs acted like bellows,
0:43:08 > 0:43:11forcing air into the lungs.
0:43:12 > 0:43:14When we breathe in,
0:43:14 > 0:43:17air flows down into our lungs.
0:43:17 > 0:43:21Oxygen is absorbed in exchange for carbon dioxide,
0:43:21 > 0:43:24which is then got rid of when we breathe out.
0:43:24 > 0:43:28The air sac system is very much more complex,
0:43:28 > 0:43:29but very much more efficient.
0:43:31 > 0:43:36It enabled a titanosaur to take in oxygen continuously,
0:43:36 > 0:43:40not just when breathing in, but also when breathing out.
0:43:40 > 0:43:43DEEP, RUMBLING HISS
0:44:04 > 0:44:08Our titanosaur wasn't the only giant living around here.
0:44:08 > 0:44:10DISTANT ROAR
0:44:13 > 0:44:16This was a dangerous world,
0:44:16 > 0:44:19where meat-eaters were giants, too.
0:44:23 > 0:44:25New evidence from the dig site
0:44:25 > 0:44:29shows that carnivorous dinosaurs were here as well.
0:44:33 > 0:44:38- Wow.- So these are some of the over 80 teeth we found on the dig site.
0:44:38 > 0:44:42And you can feel how sharp they are.
0:44:44 > 0:44:48- Oh, yes, it's serrated, just like a shark's tooth, in fact.- Absolutely.
0:44:48 > 0:44:53They actually belong to a family known as shark-toothed dinosaurs.
0:44:53 > 0:44:56We can identify the teeth at the family level.
0:44:56 > 0:45:00We know of one species that belonged to that family,
0:45:00 > 0:45:03it's called Tyrannotitan chubutensis.
0:45:03 > 0:45:06- Tyrannotitan?- Yeah, Tyrannotitan.
0:45:06 > 0:45:10- That means a ferocious giant, ferocious beast.- Exactly.- Good name.
0:45:10 > 0:45:13- Yeah.- Chubutensis is because of the area it comes from?
0:45:13 > 0:45:15Yes, this is the Chubut province.
0:45:15 > 0:45:16Great.
0:45:17 > 0:45:22Tyrannotitan must have been a ferocious-looking beast.
0:45:23 > 0:45:25With large eyes,
0:45:25 > 0:45:27sharp, flesh-eating teeth...
0:45:29 > 0:45:31..and strong legs,
0:45:31 > 0:45:34it was a fast, alert, meat-eating dinosaur.
0:45:38 > 0:45:41- And it was as big as T-Rex. - Really? Not as famous.
0:45:41 > 0:45:44- Not as famous. - Tell that to Hollywood.
0:45:46 > 0:45:49I have some sauropod bones over there I would like to show you.
0:45:50 > 0:45:55So this is one of the tail vertebrae we found at the dig site.
0:45:56 > 0:45:58There's something really interesting here.
0:45:58 > 0:45:59- You can see this groove?- Mmm.
0:45:59 > 0:46:03Well, this groove was probably a bite mark
0:46:03 > 0:46:05- made by one of the carnivores. - By one of these teeth?
0:46:05 > 0:46:08- Right.- So it was... What do you mean? Like that?
0:46:08 > 0:46:13- Exactly. Taking the flesh out of their tail.- Really?- Yeah.
0:46:14 > 0:46:15The tender bits.
0:46:18 > 0:46:20- They would be too. - Yeah, absolutely.
0:46:20 > 0:46:24Can you determine whether it was a scavenger or it was a hunter?
0:46:24 > 0:46:26We don't know if they were dead,
0:46:26 > 0:46:28I mean, they were scavenging on the carcasses,
0:46:28 > 0:46:31or if they were actually hunting and killing them.
0:46:32 > 0:46:37- Well, it didn't make much difference to the old dinosaur.- Yes.
0:46:39 > 0:46:42In a detective story, to close the case,
0:46:42 > 0:46:46you really want to know how the victim met its end.
0:46:47 > 0:46:51If our titanosaur didn't perish in the jaws of a tyrannotitan,
0:46:51 > 0:46:53how did it die?
0:46:56 > 0:47:00Clues can be found by the detailed three-dimensional mapping
0:47:00 > 0:47:03of the location of every fossil bone,
0:47:03 > 0:47:04small and large.
0:47:08 > 0:47:12That shows that the dig site contains the remains of not just one
0:47:12 > 0:47:15but seven different individuals.
0:47:16 > 0:47:18All of the new species.
0:47:19 > 0:47:23And the first thing to notice is that they are on three different levels.
0:47:27 > 0:47:30That's to say the animals must have come here
0:47:30 > 0:47:32on at least three different occasions.
0:47:38 > 0:47:41But why should they have done that?
0:47:49 > 0:47:53There are several theories as to why seven bodies
0:47:53 > 0:47:56should have all ended up at this one particular place.
0:47:57 > 0:48:00The first is that this was a seasonal climate,
0:48:00 > 0:48:02and that as the dry season proceeded,
0:48:02 > 0:48:06this was one of the last remaining pools of water
0:48:06 > 0:48:11and when this went, the sauropods that happened to be here died here.
0:48:14 > 0:48:19The second is that these bodies were swept down by great rivers
0:48:19 > 0:48:21during the rainy season,
0:48:21 > 0:48:23and then where the land levelled out,
0:48:23 > 0:48:25so those bodies were dumped.
0:48:26 > 0:48:31Analysis of the sediments around the bones shows that there were rivers
0:48:31 > 0:48:34gently flowing across this site at the time of their death.
0:48:40 > 0:48:42There was no shortage of water to drink.
0:48:43 > 0:48:45What's more, the rivers were not moving fast enough
0:48:45 > 0:48:48to shift such huge bodies.
0:48:49 > 0:48:52So the corpses weren't washed here by floodwaters, either.
0:48:55 > 0:48:57Could there be another reason
0:48:57 > 0:49:01why they all died in one place on three different occasions?
0:49:04 > 0:49:07We know from layers of ash around the bones
0:49:07 > 0:49:10that there were volcanoes erupting in the neighbourhood,
0:49:10 > 0:49:14so doubtless there were areas where the ground was warmed
0:49:14 > 0:49:18by volcanic fumes, just as they are here today.
0:49:18 > 0:49:22We also know that dinosaurs regularly laid their eggs in such places,
0:49:22 > 0:49:26doubtless taking advantage of the volcanic warmth
0:49:26 > 0:49:28to help incubate their eggs.
0:49:28 > 0:49:32So maybe that was the reason why they kept returning to the same place.
0:49:39 > 0:49:42Certainly, the excavation of the dinosaur egg site
0:49:42 > 0:49:44seems to support this.
0:49:46 > 0:49:49Nests like these have been found
0:49:49 > 0:49:53at four quite widely separated layers in the rocks,
0:49:53 > 0:49:57showing that dinosaurs came back to this particular site
0:49:57 > 0:50:02again and again and again over a long period of time.
0:50:11 > 0:50:16Ash from a volcanic eruption can sometimes fall in such quantities
0:50:16 > 0:50:19that the whole vegetation is blanketed by it,
0:50:19 > 0:50:20and killed.
0:50:21 > 0:50:24So life in the aftermath of a big eruption
0:50:24 > 0:50:27can be very difficult for a plant-eater.
0:50:29 > 0:50:31Whatever the explanation,
0:50:31 > 0:50:36individuals over several generations came to this one place,
0:50:36 > 0:50:38and died here.
0:50:40 > 0:50:42The dig is coming to an end,
0:50:42 > 0:50:46and the team have assembled a record-breaking number of bones,
0:50:46 > 0:50:50but they're still hoping to find one last piece of the puzzle.
0:50:50 > 0:50:52The skull.
0:50:52 > 0:50:58- So what number's this, 203? - Well, actually it's 223.- -23?
0:50:58 > 0:50:59Between the seven individuals?
0:50:59 > 0:51:03Yeah. Between all seven individuals we found here on this site.
0:51:03 > 0:51:06If these are neck vertebrae, could they be leading towards a skull?
0:51:06 > 0:51:08Well, yeah, that's what we're hoping for.
0:51:08 > 0:51:11We just found another neck vertebrae over there, so...
0:51:11 > 0:51:14That would be a great triumph if you found a skull, wouldn't it?
0:51:14 > 0:51:17Oh, yeah, yeah. There are only three titanosaur skulls known so far.
0:51:17 > 0:51:20- Really?- Yeah. So they're very rare.
0:51:20 > 0:51:22And that's because they're very fragile?
0:51:22 > 0:51:23Yeah, they're very delicate bones,
0:51:23 > 0:51:28and they have very light sutures between each of the bones.
0:51:28 > 0:51:32- OK, well, let's hope you find number four.- Yeah.
0:51:32 > 0:51:33Could be under there!
0:51:33 > 0:51:36Could be. Could be. We're going for that.
0:51:36 > 0:51:37Wonderful.
0:51:40 > 0:51:42Alas, it was not to be.
0:51:47 > 0:51:50- So I gather you haven't yet found the skull.- Sadly not.
0:51:50 > 0:51:54The only thing we have found out of the skull is this tooth.
0:51:57 > 0:52:01So, to complete the skeleton, the team have to reconstruct one...
0:52:01 > 0:52:03Take that piece out of there.
0:52:03 > 0:52:07..basing it on the three skulls of other titanosaur species,
0:52:07 > 0:52:11to produce one which most suits the single tooth that we have.
0:52:18 > 0:52:24The scientific team has discovered, collected, cleaned,
0:52:24 > 0:52:30scanned and copied 220 bones of our giant.
0:52:30 > 0:52:33Soon, it'll be possible to put those copies together
0:52:33 > 0:52:37to get some idea of what the living animal actually looked like.
0:52:38 > 0:52:43But the fossil bones themselves still have many secrets
0:52:43 > 0:52:45that are waiting to be revealed.
0:52:53 > 0:52:57All the theory can now be put to the test.
0:53:02 > 0:53:07We can finally get the most accurate estimate of our dinosaur's weight,
0:53:07 > 0:53:08and true size.
0:53:22 > 0:53:24It takes two weeks,
0:53:24 > 0:53:25working day and night,
0:53:25 > 0:53:27to fit all the bones together.
0:53:40 > 0:53:41SAWS BUZZING
0:53:44 > 0:53:46Wow!
0:53:46 > 0:53:47God!
0:53:50 > 0:53:53Absolutely amazing!
0:54:12 > 0:54:13Good gracious!
0:54:33 > 0:54:35SAWS SPIN DOWN
0:54:42 > 0:54:46- Well, Diego, are you pleased with it? - Yes, we are very pleased.
0:54:46 > 0:54:48It is been a lot of work.
0:54:48 > 0:54:52It has taken 40,000 man-hours to get here,
0:54:52 > 0:54:54but we're really, really happy with it.
0:54:54 > 0:54:57And does it answer some of your questions about the animal?
0:54:57 > 0:54:58Oh, yeah, absolutely.
0:54:58 > 0:55:00It answers a lot of questions
0:55:00 > 0:55:03but the good thing is it raises more questions.
0:55:03 > 0:55:07So we have a lot of research to continue on this animal.
0:55:07 > 0:55:10It's clear that this thing still wasn't fully grown.
0:55:10 > 0:55:12It's massive, but it still had room to go.
0:55:12 > 0:55:14You mean the structure of the bones
0:55:14 > 0:55:16- looks as though they were still growing?- Yeah, yeah.
0:55:16 > 0:55:20So, that raises the really big question.
0:55:21 > 0:55:24Is it the biggest so far discovered?
0:55:24 > 0:55:26Well, according to our estimate,
0:55:26 > 0:55:30this animal weighed 70 metric tonnes.
0:55:30 > 0:55:3470 metric tonnes. What would that compare with?
0:55:34 > 0:55:37That is like 15 African elephants.
0:55:37 > 0:55:40- 15 African elephants?!- Yeah. Yeah.
0:55:40 > 0:55:46We are now sure that this animal was 10% larger than Argentinosaurus.
0:55:46 > 0:55:49- The previous record-holder? - The previous record. So, yes,
0:55:49 > 0:55:53we think we have the largest dinosaur ever known.
0:55:53 > 0:55:55Fantastic!
0:55:55 > 0:55:57I can quite believe it.
0:55:57 > 0:56:02- Congratulations to you.- Thank you. - Congratulations to he, she or it.
0:56:02 > 0:56:05Wonderful! A marvellous, marvellous dinosaur!
0:56:23 > 0:56:26Piecing this complex jigsaw puzzle together
0:56:26 > 0:56:28has been a fascinating adventure.
0:56:31 > 0:56:37It all started with the discovery of one enormous thighbone.
0:56:37 > 0:56:40And then a team of 40 worked for over two years
0:56:40 > 0:56:44to excavate and put together the near-complete skeleton
0:56:44 > 0:56:49of the largest land animal yet discovered.
0:56:49 > 0:56:52And so added one further marvel
0:56:52 > 0:56:56to the astonishing history of life on earth.
0:57:03 > 0:57:07What a thrill it must have been to see it when it was alive.
0:57:11 > 0:57:12DEEP, RUMBLING BREATHING
0:57:22 > 0:57:24RUMBLING THUD
0:57:39 > 0:57:41DEEP THUMP
0:57:48 > 0:57:49TITANOSAUR ROARS