[train whistle toots] - ♪ Dinosaur Train ♪ - ♪ Once upon a time, there was a mom ♪ ♪ Her name was Mrs. Pteranodon ♪ ♪ Sitting on her nest, she heard a scratching and said ♪ - Oh, boy, my eggs are hatching!

- ♪ One by one, her kids popped free ♪ ♪ Baby Pteranodons, one, two, three ♪ - I'll name you Tiny, Shiny, and Don.

- ♪ But Tiny said ♪ - Wait, there's one more, Mom!

- ♪ The last little baby was a different size ♪ ♪ With teeth and a tail and big green eyes ♪ ♪ He didn't look anything like the rest ♪ - What am I doing in a Pteranodon nest?

- ♪ But dear old Mrs. Pteranodon said ♪ - Oh, this is your family, and I'm your mom.

You may be different, but we're all creatures.

All dinosaurs have different features.

Come on, Buddy, we'll take a vacation.

I'll get us a ticket at Pteranodon Station.

We'll travel the world in sunshine and rain and meet all the species on the... - ♪ Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ We're gonna ride... ♪ - ♪ Ride, ride, ride, ride ♪ [train whistle toots] - ♪ The Dinosaur Train ♪ - [roars] all: ♪ What's at the center of the Earth?

♪ ♪ What's at the center of the Earth?

♪ - I love that song!

It's the perfect music for our mission.

- To the center of the Earth.

- Don, Mr.

Conductor told you, we're not really going to the center of the Earth.

It's too deep and impossibly hot.

Right, Gilbert?

- That's right, Shiny.

The mantle is hot, and the core is even hotter.

As hot as the surface of the sun.

- See?

- But we are digging way down to find the perfect spot for an underground train station.

- And our next stop should be pretty cool.

- Really?

Where is it?

- Please tell us.

We can't wait.

- Neither can I.

And luckily, we don't have to.

We're here!

[train whirring] [all gasp] All off board!

- [sighs] Don: Wow, what a hole!

- Everything down here is beautiful.

- Great place for a train station, right?

- And even better place to explore!

- Especially for an amateur speleologist like me.

- A "whosabawhat-gist"?

- [chuckles] A speleologist is someone who studies caves.

all: Oh, a speleologist.

- You should've said so.

- Caves like this take millions of years to form, as the limestone is slowly dissolved away by underground rivers.

[chirping] - Dad, did you just tap me on the shoulder?

- No.

- [chirp] - Did you just tap me on the waist?

- No.

- [chirp] [both yell] [both gasp] - Sheesh, could you keep it down?

I'm sensitive to loud noises.

both: Sorry.

- Oh, I see you've met Bernie the Beetle.

He's a troglobite.

- A troglobite is a creature whose body is specially adapted for living in deep caves without any light.

- Very good, Gilbert.

- You mean he has special features?

- Like eyes that can see in the dark?

- [laughs] You kidding?

I don't even have any eyes.

both: What?

- You don't need them down here.

It's too dark.

Instead, I got these antennae.

They're extra-sensitive, so when they touch things, I can feel what they are.

- Can you see me with your antennae?

- [muttering] Three toes on the feet, a long tail.

Ah, lots of teeth.

[gasps] You are definitely a theropod.

- Buddy, you are a theropod.

- And you're not just any theropod.

You, my friend, are a young T. rex.

- I am, Bernie.

That's amazing!

It's one of the coolest features I've ever seen on a creature.

And I've seen a lot of creatures' features.

- [laughs] Thanks, Buddy.

Ooh, and you are a Pteranodon.

- [squeals] I am a Pteranodon.

I'm Tiny, Buddy's sister, and Buddy and I are here with our family and friends.

- Hiya, family and friends!

all: Hello, Bernie.

- And hey, Buddy, if you really love creatures' features, you should meet my fishy friends.

They don't have any eyes either.

Hey, everyone, come meet my new pals.

- Bernie, if they don't have eyes, how can they see you waving your antennae?

- They can't, but they can feel the vibrations of the water moving.

- That's so neat.

- Bernie, you were right.

Their features are amazing!

- Well, yeah.

But they're not my only friends with amazing features.

Carla!

Sylvester!

Cornelius!

Crockett!

- No need to shout, mate.

- Easy, Bernie.

You're making the walls shake with that noise.

- The pond too.

- I'm coming.

I'm coming.

- Everyone, I want you to meet Crockett the Cricket, Sylvester the Spider, Cornelius the Crab, and Carla the Crayfish.

- Hi, I'm Tiny Pteranodon, and it's great to meet all of you.

- Ooh, hi, hi, hi.

- Hello.

- Hello.

- Hey.

- So, Buddy, I don't know if you can tell by my friends' features, but just like me, none of them can see.

- Really?

You're all troglobites?

But you don't all have antennae like Bernie.

How do you get around if you can't see?

- Good question.

It's different for each of us.

I like to float in the pond, so changes in water pressure help me know what's where.

- And perhaps you've noticed my long legs.

They pick up vibrations in the air to guide me around.

- And the two of you have antennae, so you see with those, right?

- Sure do!

But not Crockett.

His antennae help, but his hearing helps him even more.

- Your hearing?

But you don't have any ears.

- Indeed I do, Tiny.

They're on my legs.

all: Your legs?

- [laughs] Righty-o!

So when I say, "use my ears to get round," I'm not kidding!

- I bet I'd be a great troglobite.

I'd crawl down into the deepest, darkest holes and walk around no problem, like this.

Ow!

I'm okay.

- If I were a troglobite, I'd want to be a fish swimming in the water.

- If I were a troglobite, I'd move so fast, no one would see me.

- Of course no one would see you.

Troglobites don't see.

- I bet it would feel pretty amazing to be any kind of troglobite.

You'd see the world in a whole new way.

- That's true, Buddy, and it gives me an idea for a little contest.

[whispering] I'm gonna hide four mugs from the Dinosaur Train snack cart.

Then you'll close your eyes and use your troglobite senses to find them.

First one back to the drill train with their mug is the best troglobite.

- Sounds great.

- I love it.

- Fun!

- Run around a cave with my eyes closed?

I don't know.

- I brought five mugs.

I wanna play too!

Sounds like fun.

Don't you think so, Shiny?

- [nervous laughter] Uh, it actually makes me kind of nervous.

- Well, to help you out, each of you will have a troglobite partner.

- And I'll watch you too.

I won't let you walk out of "rawking" distance.

- So is everybody ready?

all: Yes!

- Okay.

- Okay, junior troglobites, do you each have your troglobite helper?

all: Yes!

- Do you have your sticks from the train for antennae?

all: Yes!

Then get set and go find those mugs!

- I hit something with my antennae.

- Yeah, you did, and what does that tell you?

- That something's there, and I have to go around.

- Excellent, Buddy.

- This is good, but you can move the antennae more gently and feel for vibrations with your feet.

Do you feel anything?

- I do.

I can feel someone's feet stomping by.

Boom, boom, boom.

- Yes, so if someone's moving there, you know that way is clear.

Go, go!

- That's the way.

Wave the antennae and find a path.

- Ah!

- Oops!

Sorry, Shiny.

I didn't mean it.

- Oh, Gilbert, that's okay.

It was just an accident.

- Shiny, you all right?

- I don't like this.

I don't know where anything is.

I wanna open my eyes.

- Wait, you can, but try something first.

Use your ears like I do.

- But I don't have ears on my legs like you do.

- Well, then use the ears you do have and listen really, really carefully.

- Okay.

- I hit something else!

Left turn.

- Did we miss it?

I feel like we've gone so far.

- Ow.

I'm okay.

- I hear everything!

It's like I hear the whole cave.

- Which means you can see the whole cave.

Now, use your antennae and make your way across.

- Whoa.

[splashing] - I hear the pond.

Better go the other way.

[mug clinking] [gasps] That sounds like a mug!

I found them!

- Brilliant, Shiny!

- She found them!

- I hear her!

- Over there!

- Thataway!

- Come on back to the drill train, Shiny.

Hurry!

Oh, it's very close now.

We're in the home stretch.

It's Shiny in the lead, but Don is getting close with Tiny and Buddy right behind.

Don is closer, closer!

- Ugh.

I'm okay.

- Ooh, that's gotta hurt.

Now it's Tiny and Buddy picking up speed.

They're gaining on Shiny!

But can she hold on to her lead?

Yes, she can!

Shiny wins!

- I did it!

I won!

- Great job, Shiny.

You're the best troglobite for sure.

- We're all great troglobites.

You guys were right behind me.

- And here I thought you were nervous.

- Who, me?

[laughs, snorts] I was really nervous, but Crockett helped me use all my other senses.

I felt like I could really see the cave.

- Me too.

- I did too.

- Yeah.

- Same here.

- Thanks, Crockett.

I could never have done it without you.

- Of course you could, mate.

But it was a pleasure helping you out.

- Shiny, as an award for your success and your bravery, we want to give you this rock.

It's from our pond.

- It's so smooth.

It feels shiny.

I love it!

And I loved exploring this cave with all of you.

[clock chimes] - I love it too.

But unfortunately, it's time to get back on the drill train.

All aboard!

- Thanks, Bernie.

I'll always remember you and your incredible features.

- Come visit us again sometime.

Meanwhile, you hold on to those antennae sticks.

A little something to remember us by, huh?

- We will!

[all cheering] - That was really fun.

I can't wait to get home and tell Mom all about it.

So when do we go back to the surface?

both: Back to the surface?

- Are you kidding?

We're going to dig deeper.

Right, Mr.

The Conductor?

- Indeed, Mr.

The Don.

I have one more place to show you that might be even more perfect for a Dinosaur Train underground station.

- Finally, the center of the Earth.

- Well, not quite.

- A Pteranodon can dream, can't he?

♪ What's at the center of the Earth?

♪ - Hi, there, I'm Dr. Scott the paleontologist, and we're here in the Natural History Museum of Los Angeles County in the paleontology collections.

Inside these drawers are fossils, millions of fossils, and it's here that all the fossils come after they're prepared in the paleontology lab.

This is the lower jaw of a marine reptile, a tylosaur--like a mosasaur-- that lived during the age of dinosaurs.

And every fossil in here has a card that goes with it.

And that card records what kind of animal it is, when it was found, where it was found, even who found it.

This one was found by J.R. Macdonald, in 1964.

Thanks, J.R.!

Each one of these drawers then, and all these cabinets, has more fossils.

Here is another full lower jaw of another tylosaur mosasaur.

And you can see the jaw bone and the teeth inside.

It's amazing to think that millions of years ago, this fossil was part of an animal that swam in the oceans.

And here it is, housed in the museum forever, so that paleontologists, people like me, can come and do the science 'cause this is where the science really happens.

This is where we make discoveries, right here in this room.

- Hello, folks.

It's me, the Conductor.

Today, we continue our journey through the Earth's crust on a search for the perfect spot for an underground train station.

So come on along with me on the Dinosaur Train.

All aboard!

all: ♪ What's at the center of the Earth?

♪ ♪ What's at the center of the Earth?

♪ [machinery grinding] [brakes squeaking] - Well, that didn't sound good.

I'm gonna go check things out.

Be right back!

- This must be it.

We're finally in the center of the Earth.

- Don, we're not in the center of the Earth.

Are we, Gilbert?

- Nope.

Sorry, Don.

- Okay, so maybe we're not in the core layer, but we're at least in the mantle layer, right?

- Nope.

Sorry, Don.

- So we're still in the crust layer?

- Yep, right about... here.

- Aww.

- Bad news, everyone.

- We're stuck?

I knew we'd get stuck.

I knew it!

I knew it!

[clears throat] Sorry.

Continue.

- Well, actually, Mr. P, you're right.

We are stuck.

Nothing I can't fix though.

all: Phew!

- So it looks like we're gonna have to take a break from looking for the perfect spot for the new Dinosaur Train underground station.

- Yeah, but while we're here, you all should get out and take a look around.

I think you'll like what you see.

Especially you, Shiny.

- Me?

Okay.

all: Whoa!

- Oh, my goodness!

Where are we, and may we please stay here forever?

- Uh, I think this is The Cave of Giant Crystals.

I've heard of it, but I've never seen it myself.

- Those are the biggest, shiniest crystals I've ever seen!

What are they made of?

- Minerals.

In fact, you see that brownish crystal over there?

That's called topaz, and that's what broke the drill on the front of the drill train.

Hmm, probably need to make a new drill bit.

- Wait, what?

That broke the drill?

- But that doesn't make any sense.

We've been digging through tons of dirt and rock to get down here.

- Yeah, so how come that topaz rock broke the drill when all the other rocks we drilled through didn't?

- Well, first of all, topaz isn't a rock.

It's a mineral.

- What's the difference?

- Minerals form naturally in the earth and are made of the same thing all the way through.

See?

- So clear and shiny!

- On the other hand, rocks are made up of a bunch of different kinds of minerals.

Gilbert, can you grab me my trusty rock hammer?

- So wait, rocks are made out of minerals?

But how?

- Maybe minerals hit each other really hard and join together.

- That's an interesting hypothesis, Don.

- Let's test my hypothesis.

Everyone pick up a mineral.

Now, let's make a rock.

Boom.

Did we do it?

Did we make a rock?

both: No.

- Oh.

- But look!

My mineral broke.

- So did mine.

- Mine didn't.

Guess I grabbed a piece of topaz.

- So wait, some minerals are harder than others?

- Wow.

Topaz must be really hard.

I wonder if there's something harder.

- Absolutely.

There are thousands of different minerals, and some of them are harder than topaz.

- Thousands of different minerals?

- Are they always that big?

- Nope, they come in all sizes.

Minerals start small, then after a few million years, they grow to form crystals like those.

- This is all really interesting, but I wanna know how to make a rock.

both: Yeah, me too!

- Okay, while I fix the drill train, you kids go gather up some minerals.

Oh, and here, might as well take the fossil cart.

- Now it's the mineral cart.

- Come on, let's go get some crystals!

[all cheering] [both gasp] - Whoa, that mineral's bigger than I am.

- Let me see.

Yep, that mineral is definitely bigger than you.

- Okay, grab the mineral cart and follow me.

- Wow, what's that?

- Magma.

This is called a magma chamber, which is a small, underground pool of hot, molten rock.

- But it looks too goopy to be rock.

- Well, Don, it's rock that's so hot that it's melted into a liquid.

It's the same stuff that comes out of volcanoes.

- Whoa.

- You kids ready?

Take a couple of those minerals and throw them into the pool of magma.

all: Whoa, the minerals are melting!

- That is so cool.

Actually, it's more hot.

But cool, you know?

- Now what?

- Yeah, when does it become rock?

- Well, we'd have to wait millions of years for it to cool.

- Any way we can speed that up to, like, eight or nine seconds?

- No, but we can do this.

This rock was formed by that magma and all the same minerals that you kids found.

It's called granite.

- Granite, cool.

- Yep, cool magma, to be exact.

And it has feldspar, quartz, and mica.

- Huh, mica?

I like-a.

- So first, all those minerals melt into the magma.

And then when the magma cools, it makes a rock called granite?

- Correct, Shiny.

- Hmm, I wonder if all those minerals together make it stronger than topaz.

- Nope, not stronger.

But that's a great idea, Tiny.

If we can find a mineral harder than topaz, maybe we can stick it on to the broken drill bit.

- Then we can use that extra hard mineral to dig through the topaz and get back home.

- But where are we going to find a mineral harder than topaz?

- There's gotta be one down here somewhere.

Come on, let's split up and search.

all: Yeah!

- And in case you find something, here, these will help you break it free.

- A tiny hammer.

[squeals] I love it.

[all cheering] - Aww.

Hmm.

- Ugh.

- This is without a doubt the shiniest place I've ever been.

I wonder if I could live here when I grow up.

I'll have to ask Dad if-- [gasps] Sparkles!

[squeals] [grunts] I know, I'll use my little rock hammer.

[clinking] Almost got it.

Almost got it!

All right, I--whoa!

[yelling] Uh-oh.

Guys, little help here!

[all gasp] - We're coming, Shiny!

[grunts] - Dad!

- Shiny!

Whew.

We saved you.

- Um, how did you save me if we're all in the cart and the cart's still moving?

- Uh, good question.

Buddy?

- Oh, uh, well-- [all yelling] - Everybody lean left!

[all grunt] Now lean right!

[all grunt] - Ooh, crystals!

- Hi, bugs.

[gulps] - Gah, I'm not feeling so well.

- Well, then you're really not going to like this next part.

[all screaming] - Okay, I'd like to stop now.

- Hey, look up ahead!

It's the drill train.

- Anyone have any idea how to stop this thing?

- Everybody, hammers out!

[all yelling] [all gasp] - My mineral!

- Huh, I wonder if the kids had any luck finding a mineral harder than topaz.

- My mineral!

Is it brok-- - Shiny, is this yours?

Do you know what this is?

- The shiniest mineral I've ever seen.

- Yes, it's a diamond, the hardest mineral in the world.

Why, with that diamond attached to the front of the drill, we'd be able to dig through anything.

- Oh, so we can continue our search for the perfect spot for the Dinosaur Train underground station.

- Yes, onward to the center of the Earth.

- Uh, well, Don, if we dig any deeper, we'll get closer to the mantle and then the core.

- All right, let's go!

Mantle!

Core!

- Uh, Don, the mantle is really hot, and the core is even hotter-- as hot as the surface of the sun.

- Oh.

Onward to the surface of the Earth.

- All right, let me go put this diamond on the front, and we can g-- Yes, Shiny?

- [whispering] - Well, Shiny, I think that's an excellent idea.

- What'd she say?

- [clears throat] Ladies and gentlemen, may I present Shiny's great idea and welcome you to the future location of the Dinosaur Train underground station!

[all chattering] - Great idea, Shiny.

This place is perfect.

- [laughs] Mission accomplished!

Great job, Team Pteranodon.

Does this mean we can go home now?

- Why don't you all climb on the train?

With this diamond and Gilbert's help, I should have this train up and digging in no time.

[all cheering] - That was the best trip ever.

We dug a huge hole.

- Met a new friend.

- Uh, hi.

- Dug a huge hole.

- Saw more shiny minerals than I've ever seen in my entire life.

- Dug a huge hole.

- Learned all about the layers of the Earth.

Crust, mantle, core!

- Dug a huge hole.

- Found the perfect spot for a new train station.

- Dug a huge hole.

- Got over most of our fears about going underground.

- And don't forget, we... all: Dug a huge hole!

- [laughs] I knew it.

You were all as excited about it as I was to find out... all: ♪ What's at the center of the Earth?

♪ ♪ What's at the center of the Earth?

♪ - Hi, I'm Dr. Scott the paleontologist.

What do you think these are?

- They're rocks.

- Good guess, but these are a little different.

They're called minerals.

Rocks are actually made of minerals.

Most minerals form way down deep below the surface of the Earth where it's very hot.

And many minerals that we find today were around before the dinosaurs.

both: Ooh.

- When these shiny minerals are first discovered, they're often rough and dirty, sometimes looking like broken glass.

[glass shatters, chimes tinkling] But once they're carefully cut and polished, well, they look... all: Beautiful.

- So whenever you see a beautiful, polished mineral like a diamond or a ruby, think about how it formed deep within the earth long ago, maybe even before the time of the dinosaurs.

All right, remember, get outside, get into nature, and make your own discoveries.

- We love playing games.

- Like All Aboard!

- You can play too online at pbskids.org.

- And lots of other games!

- There's so much to learn about all kinds of dinosaurs.

both: Go to pbskids.org.

- ♪ The Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ Dinosaur Train ♪ - ♪ We're gonna ride... ♪ - ♪ Ride, ride, ride, ride ♪ [train whistle toots] - ♪ The Dinosaur Train ♪