Planet Dinosaur: Ultimate Killers Page #4

---

(GROWLING)

(ROARING)

This group have congregated to

take advantage of an annual event.

A vast herd of Centrosaurus

is on the move.

Unwittingly, they're walking

towards almost certain death.

In Dinosaur Provincial Park,

thousands of bones have been discovered

scattered across the same rock layer.

They belong

to the horned dinosaur Centrosaurus.

And they appear to be

the bone beds of vast killing fields,

sites of wholesale slaughter.

Seasonal monsoons drives

the Centrosaurs inland,

away from coastal flooding.

(THUNDER CLAPPING)

(ROARING)

Herding behaviour protects the many,

but at the expense of the few.

And things are about to get worse

for the Centrosaurs.

With a flooded river ahead

and the Daspletosaurus behind,

the stage is now set for a massacre.

But despite the rich pickings,

it's not the Daspletosaurus

that are responsible

for the scale of the slaughter.

There's an even more deadly killer

at work here.

The real killer is the weather itself.

Recent studies

of this dense bone bed indicate

that 96% of the bones

are of a single species, Centrosaurus.

And relatively few of the bones

display any bite marks.

The fossil evidence suggests

that this was a mass drowning,

the result of widespread

seasonal flooding.

An event that we have seen repeated

in over 20 different sites.

And when the waters recede,

new opportunities emerge.

(SCREECHING)

But even in the fight for rotting flesh,

Daspletosaurus's authority is absolute.

Tyrannosaurs' domination of the globe

might have been total

had it not been for a strange quirk

in the arrangement of the continents.

75 million years ago,

the planet had a clear

north-south divide,

with no physical link between

the parts of the globe.

It meant the Tyrannosaurs couldn't

spread to the southern continents.

Here, a different type of killer

reigned supreme.

These were Abelisaurids.

In the last 10 years,

Madagascar has provided

the most comprehensive evidence

about these predators.

70 million years ago,

Madagascar was already an island.

In the Cretaceous period,

Madagascar was subject

to devastating droughts.

For big predators like Majungasaurus,

scavenging is the only way to survive.

(INSECTS BUZZING)

We thought Majungasaurus

was the top predator here.

But then in 2003,

some bones of a number of Majungasaurs

were reported gouged with teeth marks.

It appeared there was a bigger,

more brutal killer at large.

(SQUAWKING)

(GROWLING)

(ROARING)

A carcass will attract

every big predator for miles around.

(GROWLING)

A male Majungasaurus.

It is more than capable

of challenging for the carcass.

(ROARING)

This fight is about more than just

Rate this script:0.0 / 0 votes