Name: Video 4.7.4: Dinosaurs - Prof. Phil Manning
Uploaded: 2016-08-22T20:27:48.533Z
Duration: PT4M23.318S
Description: Watch this video about Video 4.7.4: Dinosaurs - Prof. Phil Manning for Lectures Part IV: Carboniferous through Cretaceous in 我们的地球：气候，历史和进程.

You can trace the evolution of the dinosaurs right through the Triassic,

Jurassic, and into the Cretaceous periods.

They were remarkably successful evolving,

diversifying into multiple species, many of which we know and love.

It is ironic one of the most known species to science is that of Tyrannosaurus Rex.

This is an animal that represents the last gasp of the dinosaurs.

We find their fossil remains in the Hell Creek formation of South Dakota,

North Dakota, and Montana in the USA.

These are remarkable fossils, an apex predator, the ultimate

terrestrial bone-crunching animal, with a skull nearly two meters long, and

a body some twelve meters long, weighing in at about seven to eight tons.

This was possibly the ultimate terrestrial predator.

It is interesting to think when we look back in time,

this animal was alive some 66.4 million years ago.

We are closer to T-Rex, than T-Rex is to its own ancestors,

way back in the Triassic Period.

Dinosaurs are one of earth's evolutionary success stories.

They're remarkable creatures.

They evolved some 230 million years ago and were successful

right up to the end of the Cretaceous period for the whole of the Mesozoic.

That is some 175 million years, which is remarkable for any group of animals.

We will be lucky to be as successful as the dinosaurs.

The 75 million years that was the time when dinosaurs literally ruled the earth

from the Triassic, through the Jurassic, into the Cretaceous period,

the planet was a very, very different place.

There were no ice caps, we were in a hothouse world.

It was a world which was very different in terms of the relative position

of the continents.

From a super continent, Pangea, at the beginning of the age of the dinosaurs,

which gradually broke up as we moved into the Jurassic Period,

by the time we get into the late Cretaceous,

you might begin to recognize Earth, if you were looking at it from space.

Most people think of dinosaurs as being ended by a major extinction event, but

it was, in fact, one of the biggest extinction events

ever to occur on our planet that began the age of the dinosaurs.

The Permo-Triassic extinction, some 250 million years ago,

was the time when life literally stood still.

Some 95% of species on our planet became extinct.

This is the world that the dinosaurs would inherit.

A massive impact event where a meteorite or comet smashes into a planet will

no doubt have huge effect to all of the organisms on the planet, both plants and

animals, however is this the single cause behind the extinction of the dinosaurs?

Because localized impacts from a meteorite crashing into Earth will be significant.

But on the reverse side of the planet,

the chances are its impact would have been felt far less.

There are multiple reasons for dinosaurs becoming extinct.

And scientists are still looking into the evidence which is

left in the fossil record to piece together

what happened at this pivotal point in the evolution of life.

One thing that is absolutely clear is the largest of the dinosaurs did become

extinct.

However, their descendents, the birds, which are in many respects

avian theropods, dinosaurs, they made it through the KT boundary and

they form one of the most diverse groups of animals on the planet today,

with nearly 10,000 species of birds living today.

So we still share, in some respects, our world with the dinosaurs.

Video 4.7.4: Dinosaurs - Prof. Phil Manning

我们的地球：气候，历史和进程

与讲师见面