Today I will be answering your questions from twitter.

This is dino support at Tokaji sense una.

Us.

What's the scariest dinosaur?

I think the scariest looking dinosaur would have been spinosaurus simply because it had this huge sail on its back.

But I think here in the United States the T rex is definitely the people's favorite.

Here's part of the T.

Rex tooth.

The largest tooth including the roots gets up to about seven or eight inches in length.

These cutting edges are serrated like a steak knife.

T rex ate the whole prey.

We have fossil droppings of T.

Rex and they show us that it ate the meat and the bones crunched up the bones much like some big crocodiles do today at Ricky Dell's us scientifically and historically speaking, how do we know what dinosaurs sounded like?

Surely the sounds the movies have taught us are just guesses.

No.

Well indeed there are just guesses.

In fact it's quite likely that dinosaurs were much quieter than people give them credit for birds sing but most reptiles don't make much in the way of sounds except for hisses and grunts.

So we think that dinosaurs would have done things like that.

But certainly not lion raw that Hollywood wants us to believe E.

V four N two K four us when I die and go to heaven.

First thing I'm asking God is what the Jurassic park get wrong, Jurassic park was made as an entertaining movie.

Not as a science documentary.

The star of the movies Are the raptors here is an actual skull of an adult velociraptor.

The filmmakers decided that it looked too puny and they needed something bigger strangely enough.

Shortly after this was filmed, people found a really gigantic raptor out in Utah.

And since then other giant raptors have been found in South America and in Asia.

So there were giant raptor around.

But there were in fact much bigger than the ones in the movie.

The movie claims that T rex could only detect prey by motion.

In fact when we study the brain case of a T.

Rex, we find that it had very large olfactory bulbs which are part of the brain that picks up information from the nose.

It had very large opening for the optic nerve which is the nerve that transmits information from the eye to the brain.

And it had a very complicated inner ear that allowed it to here at least a wide range of low frequency sounds.

So it would have smelled the actors in front of its snout and it would have been a very short movie indeed.

At Emo here a western, How did the asteroid kill every dinosaur like doesn't an asteroid hit like one general area rather than like the entire world.

The asteroid theory is a very flat earth theory.

There's no flat earth.

The earth is a sphere.

What happened was when the asteroid happens to impact, it released the equivalent of 100 million megatons of energy and this basically melted this huge asteroid which was six miles in diameter and this sent up a gigantic clouds of glowing material up into the atmosphere.

This would spread around the world.

We see this even today when a volcano erupts volcanic dust sweeps all around the world.

Imagine a world where suddenly it's raining drops of molten glass, that's what was happening.

And so basically every larger animal at that point died and that's why the dinosaurs were wiped out probably within a matter of hours at most.

A matter of days at Lauren Berger us, How do they know what color dinosaurs were for many years, we really had no idea what color dinosaurs had.

In fact, people sort of assume that like many of the modern lizards, snakes, crocodiles, turtles, it would have been sort of greenish brown and that's what you see in all the old dinosaur books.

However, in recent years, thanks to some remarkable discoveries in china, we actually found out what some dinosaurs looked like and it was a real revelation.

We found that some of the little feathered dinosaurs actually had color patterns as vivid as those in modern birds.

There is a dinosaur called cow long and it had beautifully iridescent feathers.

So it would have looked like a big starling with nasty cloth.

So the dinosaur world was far more colorful than we were previously thinking at T six li us.

So why were dinosaurs so big back then.

But now animals are small.

Scientists go a lot of dinosaurs were big but there were also small dinosaurs.

In fact there's one dinosaur that's barely over two ft long.

Do you live in an environment where it's advantageous to be big for your particular mode of life?

And there's some places on earth where the rules are reversed often on islands.

Generally large animals become dwarfs about 15 million years ago.

A gigantic hedgehog lived on an island.

And what is now Italy in other parts of the mediterranean, there were tiny elephants running on that would have actually been nice little pets if we had been around at that time.

God studies us.

How many species of dinosaurs are there?

I want to know all of them right now.

There are about 1100 described species of dinosaurs other than birds.

Even very conservative estimates put the number much higher anywhere between 7000 and that may have been even more.

One important thing to keep in mind is we are much closer in time to a T.

Rex than the T.

Rex most to a stegosaurus.

We now have classified this myriad of species by looking at various parts of the skeleton, the most obvious part of the skeleton.

It's the hip region.

When you look at the T.

Rex over my shoulder here you can see a hip girdle that has three bones with the front bone, the pubic pointing downwards worth In the so called bird hipped dinosaurs which is unfortunately misnomers and nothing to do with birds.

You get hip region that has the pubic bone pointing backwards.

There are many more subtle anatomical differences.

But basically there are two large groups of dinosaurs.

The lizard head, dinosaurs also called Cilicia and the bird hipped dinosaurs called anesthesia at lust clothes us by the T.

Rexes have little as arms that does not sit right with me.

For a dinosaur.

T.

Rex had really small but very powerful arms and you can see this here on our pride and joy.

Nobody really knows why T.

Rex has tiny arms.

It has been calculated that the arms was still strong enough to lift up to £600 of weight.

Earlier, relatives of T.

Rex still have longer arms.

Other predatory dinosaurs actually get increasingly longer arms which eventually become wings and birds at solar wings.

Since when were pterodactyls, Not dinosaurs.

Since ever dinosaurs and pterodactyls are related, but pterodactyls have nothing to do with dinosaurs.

They have a early common ancestors but they diverged in their evolution quite dramatically.

Pterodactyls became flying creatures wings very different from those of birds, dinosaurs were mostly land dwelling animals and only a few forms later on evolved into birds which have very different looking wings.

At Trooper Snooks asked the question of the day, why did the early mammals and birds and fish like sturgeon etcetera not become extinct when the dinosaurs.

That's a very good question and in fact it's one of the great mysteries of paleontology, it's basically different life strategies.

Small animals can hide a lot of small animals are also able to go without food for long times.

Was a large animal cannot.

Most dinosaurs went extinct and only one group of dinosaurs.

Birds survived.

Birds, as I just said, are dinosaurs because they descended from small meat eating dinosaurs, just like we are primates because we descended from other kinds of primates.

We now have a beautiful series of fossils documenting all of the stages between little predatory dinosaurs like that and birds that would have been recognizable as a bird to anyone alive today.

It's very rare that you get such a nice continuation of fossils between one group and the group that it gave rise to at three boat paleo who would win in a fight camera source or an adult, an adult titan and Camaro source lived at very, very different points in time In adult tightened at the end of the cretaceous period about 66 to 68 million years ago and Camaro source about 100 and 50 million years ago.

My money would be on the Camaro saurus simply because Kamara sauce got a lot bigger.

Both however, were harmless plant eaters and so I don't think they would have really fought each other at harry butt cheek us.

What was the climate when the dinosaurs roamed the world in which dinosaurs lived was generally a fairly warm one.

However, at high latitudes where the sun would disappear for months at a time, it would have been quite cold and we actually have even evidence from fossil soils that there were permafrost soils in some areas.

Yet dinosaurs lived there.

Dinosaurs really could cover almost any environment that you can imagine.

We know dinosaurs that lived essentially under sub polar conditions.

You know, dinosaurs that lived in really tropical regions.

We know dinosaurs that lived in deserts.

So basically in a warm period of geological history, there were every At Udonis Haslem 69 us.

How are fossils of things?

Don't those beep just disintegrate?

Well, fossils are a thing.

They're real three dimensional objects.

Here's a limb bone of an ostrich mimic dinosaur that's about 90 million years old.

Basically.

What happens is after death minerals infiltrated this bone from the ground water around it and they contained a lot of iron.

That's why it has this yellowish brown color and gradually filled in all of the spaces in the bone.

Sometimes the actual bone is still pretty much preserved, but in most cases the bone has changed just ever so slightly so that it's no longer possible for instance, to extract biomolecules like DNA from it at the art 3 15 US.

Bird dinosaur feathers, dinosaur scale or did they have a lot of bird sized feathers.

The really gigantic dinosaurs by and large did not have feathers.

We only know one really large tyrannosaur from china that lived in a very cold environment and had feathers.

Most of the dinosaurs that we know that had feathers.

Were animals up to maybe five or six ft in length.

And they had bird sized feathers.

And we know this because the bones have little bumps on them and you can see them when you take a chicken apart.

They're called Krill notes and that's where the large flight fails and the burdens at.

Mr.

Soak us idea what was the smartest dinosaur like?

Would they have used tools, build shelter?

How much could they understand about the world?

Some of these little predatory dinosaurs have really large brains.

They have the sort of bulging area here, much like you would see on a bird skull.

So these little dinosaurs probably had cognitive abilities similar to those that we see today in hawks, owls and particularly in crows and Ravens.

Crows and Ravens have repeatedly shown their ability to solve relatively complex problems.

And some birds have sort of minimal kinds of tool use as well.

And something like that is not beyond the possibility for these early dinosaurs as well At from help us.

When did the first humans discover that there were dinosaurs?

I really want to know how we first figured out.

Giant giant giant dinosaurs roamed the Earth.

The first record that we know of a definitive dinosaur is from the 17th century in England.

When robert Klotz described a part of a thighbone, he didn't know what to make of it.

He compared it to giants of legends.

President thomas Jefferson couldn't conceive of the fact that animals had gone extinct even though he found fossils of extinct animals on his estate in Virginia.

He thought that these animals still existed somewhere alive out west.

And that was one of the reasons he sent to Lewis and Clark expeditions out.

The Smithsonian got into the dinosaur business early in the 20th century and here's an old photograph.

This was taken in the 19 thirties, an excavation in progress and you see people here chipping out large blocks of rock that have bone in them and then are taken back to the laboratory where the actual excavation begins.

We can glue it back together, clean its surface and ultimately it's ready for study and exhibit at half past owns us.

Who comes up with these dinosaur names?

Like what if a dinosaur were named Hank?

Why do you got to make names so complicated?

The scientists who described the dinosaurs come up with the names.

Each animal has a genius and the species name and in the case of dinosaur names, it's the same.

It's tyrannosaurus rex.

In that case it's actually one of the best names ever chosen for dance because the research I wanted to portray it as the tyrannical creature that ruled its ecosystem and because of its big size, it's called rex which means king.

I've been very fortunate that somebody named dancer for me there's an animal called handsome, which is a little bone headed dinosaur, which I sort of taken a back handed compliment that I am born at it.

But it's a nice thing because it kind of immortalize you messing us.

How did?

T rex asleep like curled up roosting like chicken asking for a friend T rex presumably crouched down just like a lot of birds do when they're resting.

However, we actually have found dinosaurs that were preserved in burrows where they presumably were sleeping or at least hanging out and some of them are kind of curled up at paul Garcia NBA as how did the brontosaurus weigh 23 tons when it only ate plants.

You have to imagine that these dinosaurs probably spent every waking minute eating.

The other reason that brontosaurus is so big is if you eat plants, you have a big problem.

Much of the plant food that animals and people eat is made out of cellulose.

And so you need a very large gut to accommodate bacteria and other microorganisms that can break the cellulose down into fatty acids and sugars like glucose that the host animal can actually digest.

So in order to be a full time plant either you need a really large gut at allergy leg in us.

We're dinosaurs cold blooded or warm blood.

I genuinely have no clue.

Well this has been a matter of scientific debate for many years but we now think that dinosaurs have a mixture of body temperature strategies.

The little feathered dinosaurs, we're warm blooded, much like the descendants birds.

But some of the really large dinosaurs actually were either warm blooded or cold blooded because when you have a really large body mass and live in a warm climate it doesn't really matter either way at our three I.