02/12/2015 Newsround

Hello, Leah here with Wednesday's Newsround.

First exciting news for dinosaur fans.

Over 100 fossilised footprints have been found on the Isle of Skye,

They're from the largest dinosaurs that ever lived, the sauropods,

They lived at what was the the biggest dinosaur site in Scotland.

We always want to find dinosaur bones, but sometimes people

But in many ways footprints are more valuable.

Records of dinosaurs moving around right here.

So we can tell a lot about how big they were and how they moved.

So what are the top five dinosaur discoveries that changed the world?

Number one goes to the Megalosaurus Bucklandii, discovered

It's a massive deal because it is a massive deal because

it is the earliest discovered and scientifically analysed dinosaur.

Although we have fossils of its bones, jaws and teeth,

In at two is the Archaeopteryx lithographica, a fossil found back

in 1860, by accident in a quarry in Germany with a crow sized body

The fossil is a big deal because around the birds bones were

It's the first evidence that birds and dinosaurs were close relatives.

The diplodocus skeleton, discovered by a man called

It's the biggest dinosaur in the world

and he found a complete skeleton back in the 1890s in the USA.

Carnegie made replicas of it and sent them to museums

around the world, including one that's at the National History

In at four is the Deinonychus antirrhopus, or Terrible Claw.

This feisty fellow was discovered back in the 1960s America was the

first time we realised that dinosaurs can be fast moving, highly

Finally at five it's the Sinosauropteryx.

In 1996 it was discovered in China, virtually complete.

The most exciting part was the trace of a wispy fringe

This led to the discovery that many dinosaurs were actually feathered

Next to the superfast, prehistoric mega-shark called a megladon.

Megladon millions of years ago and looked like a white shark but it was

much heavier. Its teeth could grow up to 18 centimetres, roughly the

size of my palm. Until now no one knew just how fast it was and it was

one of the speediest in the sea. It swam at five metres a second, double

the speed of the great white shark, the fastest land and oceans now. It

is faster than a dolphin and its wings at 3.4 metres a second. The

Greenland shark is the slowest swimming shark that covers three

metres a second. It was bigger and heavier and had to swim faster to

keep oxygen pumping around its body to survive.

Now, who doesn't love an online cat video?

We all do, and now they could soon also be big stars at the cinema too.

With some films already shown in the UK and America,

Colin Paterson's been finding out if it really is a purrfect idea.

Thousands in a field watching cat videos. It was nice to know that I

am not the only weirdo who sits on the Internet and watches animal

videos. In Minneapolis there is now an international cat video Festival.

There are all these good-natured people coming together to do

something unbelievably ridiculous. It could become common in Britain.

There have already been dedicated events in both Deptford and Glasgow.

It is cats! I love cats. Not everyone is convinced these antics

really belong on the big screen. My reservations are about why people

would come out for something that is freely available online to them.

With millions watching online every day and some Internet cats already

having their own agents, it could be the likes of Angelina Jolie and Don

-- Johnny Depp that will struggle for time at the local cinema.

That's all from me and the Newsround team. Ayshah's back in the morning.