How to Build a Dinosaur Page #6

---

Paul and his team need Luis's advice on

a couple of issues.

There are several unknowns,

and a complete tail has never been found.

So, on the older drawings that we have,

there's maybe 53 tail vertebra.

The newer thinking is, there's close to 43.

Palaeontology, mostly it's a soft science,

so theories change with new evidence

that is found.

One of the big questions about T rex

is what it's surprisingly short arms were used for.

They might have been used to hold on to prey,

or to push the body up from a sitting position

- no-one knows.

And that's partly because each arm

is anchored to the body

by the shoulder blade or scapula,

and there's no easy way of telling

exactly where that sat.

With the scapula I've seen

they've gone up closer to the vertebra

on the backbone.

I've also seen where they're lowered almost to

where the belly is.

There's parts of the front end of the scapula,

the coracoids.

Some people think they go together this much,

some think this much.

But that all has to do with how everything hangs on

the front end of this,

and also how the hands were used.

Those arms are just about the same size as

a human arm.

The 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.

They're flattened

and they don't really have the curvature

that they may have had

when the animal was alive, before.

It's really difficult to fit them on the sides

of the ribcage.

I guess that that's the nature of the beast.

We're going to have to find a compromise

and we'll live with it.

Back in LA, there are two months to go before

the exhibition opens.

The three T rexs are now installed.

Oh, this is a bit different.

There are dinosaurs here.

- Now, these guys I recognise.

- Yes.

So, this is your famous Thomas.

- Can we get up here?

- Sure.

- Yeah?

- You can... Absolutely. Feel free.

Face to face with a baby T rex.

'With three T rexs 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.'

- Having a series of juvenile skeletons gives

you insights into the way dinosaurs grew?

- Absolutely.

The dinosaurs had growth spurts, so this animal

- is estimated to have died at the age of two.

- Right.

And this one here is estimated to have died

at the age of 13.

There's, you know, there's a size discrepancy here,

but they're also 11 years apart.

- Mm.

- Yet this animal is only four years...

- Yeah.

- ..older than this one, yet is enormously

bigger than this one.

What this is telling you is that between 13 and 17

they were able to add about 1,500 pounds -

that's, what, 750 kilograms a year.

Wow. And when you see the two skeletons close

to each other like that,

you really get a kind of physical impression of that.

'Although Thomas towers over the younger T rexs,

'even he wasn't fully grown.

'But at about 17 years old

'he was already 11 metres long and over

three tonnes in weight.'

- So, this is a juvenile? This enormous skeleton?

- Indeed, indeed.

- This is an animal that probably died at the age of 17.

- Right, OK.

- So, rather young.

- So, still a teenager?

- And you can tell that it's a juvenile,

not only based on the histology on the bone tissue,

for which we have studies of it,

but also because there are many bones that would fuse

when the animal was a full-grown...

- Yeah.

- ..that have not yet been fused.

One of them is here, the calcaneum and

the astragalus are completely unfused,

and both with the tibia.

'And it's not just the phenomenal speed

at which they grew

'that Luis is shedding light on.

'The final addition to this platform

'will be the carcass of another dinosaur

- the T rex's dinner.

'It will give us an insight

'into how the three T rexs may have interacted.'

So, how realistic do you think it is

to show three tyrannosaurs coming together like this?

We have evidence suggesting that these animals

lived in groups.

It's very reasonable to imagine a scene like this,

in which you have a juvenile

eating a carcass of a duck-billed dinosaur,

and other individuals coming and being attracted

by the carcass.

If there's going to be a skeleton here representing

an edmontosaurus,

a duck-billed dinosaur, being eaten by the T rexs,

is there actually evidence that they ate

this type of dinosaur?

You have evidence in the shape of bones of duck-bills,

like edmontosaurus,

that have tooth marks, essentially,

and those marks, those scratches on the bone,

coincide well

with the shape of the crowns of the teeth

of Tyrannosaurus rex.

That's quite forensic.

- So, you've actually got gnaw marks on a duck-billed dinosaur.

- Yes.

- Fantastic.

But the exhibition isn't only about T rex.

In amongst the 20 major mounts will be fruitadens,

the smallest dinosaur ever to be found

in North America.

Working from his own illustration,

Doyle has created five fruitadens.

It's the first time that this dinosaur has ever been reconstructed.

This is full-grown, to scale.

It's a very small dinosaur and one of

the smallest in the world.

Because the specimen

is so fragile and sparse,

the information that we can gather,

a lot of it is inferred,

or we're guessing that it fits with a group of animals,

based on what information we do have.

We don't have a full skeleton.

By comparing the size of a forelimb to a thighbone,

it was clear that fruitadens was bipedal.

And by studying close relatives,

it's possible to get a good idea

of what a complete skeleton would have looked like.

The real challenge was to turn that skeleton

into a fleshed-out animal.

Musculature can be inferred from the bones.

You can see muscle attachments.

Every animal has some sort of muscle

that pulls the leg back

and also something that supports the leg in front,

a calf muscle, gastrocnemius,

or any sort of tendon that would go down to the feet.

That's something that exists on every animal

that walks on land.

With large teeth for mashing plants

and sharper teeth for eating insects and worms,

we can even tell that fruitadens was an omnivore.

The final piece of the puzzle in recreating

this animal

is its colour, and that's something

we can't be sure about.

If you push things too far,

you go with polka dots and purple and pink,

your audience simply won't believe it.

But if you draw upon the examples of our living animals,

we can actually gain a lot just by looking

at crocodile skin

and the colouration and maybe some

lizards and fish, even,

and it will remain believable.

Like everything in the exhibition,

the finished work will have to be approved by Luis.

So, one thing we need to keep in mind

is that although we want to have

some variation in pattern,

or in colour, they obviously all need to

look the same species.

You going to give me some freedom

Rate this script:0.0 / 0 votes