Transcript of Episode 1: Earth Science
>> Rick Crosslin: On this Indiana Expedition, we’ll follow dinosaur fossils from
South Dakota all the way to the Paleo Prep Lab at the Children’s Museum of
Indianapolis. We’ll go on the smallest field trip ever to search for microfossils.
We’ll explore the depths of an Indiana cave. And we’ll get our hands dirty at an
Indiana coal mine--All in the name of Earth Science.
>> Rick Crosslin: Try it yourself.
Let’s go check it out. Come on!
>> Announcer: Indiana Expeditions with Rick
Crosslin is made possible through the
generous support of:
The Doctor Laura Hare Charitable Trust.
Enhancing Indiana’s natural environment
through preservation and protection of
ecologically significant areas and promoting environmental education,
stewardship, and awareness.
SEFI, the Science Education Foundation of Indiana, investing in Indiana’s youth
by encouraging them to become scientists and engineers and to practice their
careers in Indiana. Details at SEFI.org.
And the Center for School Improvement and Performance, Indiana Department
of Education.
>> Rick Crosslin: Today, we’re gonna take a closer look at the ground beneath
our feet. I’m in South Dakota, a great place for Earth science discovery. Behind
me are a group of Indiana scientists and teachers digging up fossils that give us
clues to what ancient life was like 65 million years ago.
I bet you’re not used to seeing teachers do something like this.
>> Teacher: It definitely takes you beyond your comfort range.
>> Teacher: This is what kids expect all dinosaur bones to look like.
>> Teacher: You don’t understand how exciting it is to find a bone until you hit
your first clink, you know, and hear the bone.
>> Teacher: That excitement will build in the kids, and who knows, maybe I’ll
inspire one of them to be a paleontologist one day.
>> Rick Crosslin: This is science! Try it yourself!
(MUSIC)
>> Rick Crosslin: Millions of years ago, the South Dakota that we know today
was a densely vegetated coastal wetland. This dig site was once home to the
Edmontosaurus, a huge plant-eating duck-billed dinosaur that traveled in herds
of thousands. Now it’s a deathbed.
>> Victor Porter: Edmontosaurus is a duck-billed dinosaur, a herding dinosaur.
He looks like a big duck. His head looks like a duck.
>> Dallas Evans: Basically, it’s the largest duckbilled dinosaur there is. They’re huge. They’re TRex size. They traveled in huge numbers. If you
think about a thousand of them walking through this
valley in migration, they would have eaten
everything in sight. They would have been very
noticeable. And of course some would have died.
This one layer of bone had over ten thousand individuals. And there are over
three hundred plus bones per animal. That’s tens and tens of thousands of bones
here.
>> Rick Crosslin: This is what is known as a secondary deposit. These dinosaur
bones were brought here from another place.
>> Dallas Evans: And we know it’s by a river sediment because the sand’s still in
there. We get the little river animals. We’ll get crocodile. We’ll get turtle. We’ll
even get fresh water gastropods. What killed them we don’t know yet. Did they
die year after year at this spot? Or do we have a mass killing at one section and
then bones washed here later? A lot of questions to answer.
>> Rick Crosslin: One thing about bones tumbling down a stream, is that they
don’t stay together. But for a paleontologist, this just means more time to play in
the dirt.
>> Dallas Evans: That kind of makes it fun. If you’re putting a skeleton together,
you’ve got to do a lot of work. If you dig the left humerus, you keep digging until
you find that right humerus the exact same size. We have nine or ten of those
bones at work, and none of them match. So you have to dig a lot of bones to do
the 320 bones of one duck-billed dinosaur.
>> Rick Crosslin: This is what the full skeleton of an Edmontosaurus looks like.
These are the bones we’re after.
>> Victor Porter: Right now we’ve got, I don’t know,
30 or 40 bones already uncovered over the last
couple of days that they’re steadily, right now, just
gluing and we’re foiling them and getting them out of
the ground. We figure in the next few days we’ll
probably have about 100, 150 bones ready to bring
back to Indianapolis.
>> Rick Crosslin: It sounds like they found a lot of bones, but there are
thousands yet to be discovered. And there’s only one way to do it.
>> Dallas Evans: You’ve got to get out, walk around. Sometimes you can’t even
walk; you’ve got to get on your hands and knees and crawl and look for broken
bits of bone. You find the broken fragments and you try to find where they eroded
from. You look up on the hillside. You kind of scramble up the hills looking, and
you’ll see a bone fragment just sticking out of the side of a hill. And that’s where
you know to dig. But every single one of them is found by people doing footwork,
just getting a sunburned neck basically,looking down on the ground and seeing
what they can find.
>> Rick Crosslin: Cretaceous gumbo. All it’s missing is the top of the food chain,
T-Rex.
110 degree heat, blowing winds, all forgotten as we uncover one duck-bill fossil
after another. Then I made an interesting discovery. At first I thought it was a
Nano tooth.
I’m hoping it’s a Nano tooth.
Often left behind by the Nanotyrannosaurus, a smaller relative of the T-Rex.
It’s a pretty interesting curving bone.
Further observation revealed that it was actually a claw, a first for this site.
Holy smokes, that’s pretty cool. We don’t know what. theropod, meat-eater. We
found their teeth. We found their bones. It looks like we found their claws.
Victor explained the importance of this find.
Victor Porter: To find a claw tells you that the
dinosaur died here. The teeth are just a sign
that the dinosaur fed here, but that claw meant
that that dinosaur actually perished. So not
only all of a sudden you’re saying, ‘Oh wow,
another element here. The dinosaur died with the duckbill’
So all of a sudden you have two dinosaurs that died.
>> Rick Crosslin: The scavenger and the scavenged.
Finding something new is the spirit that drives us. That’s why we do what we do.
The world is an open book of possibilities and it’s available to anyone. So keep
your eyes open, you never know what you might find.
That’s the tail of a baby.
>> Victor Porter: That’s the tail of a--I don’t know if it’s the tail of a baby. It could
be the tail of an adult. It’s just the very end of the tail.
>> Rick Crosslin: It’s the tail of a dwarf adult!
>> Victor Porter: That’s the end of the tail.
>> Rick Crosslin: The end of the tail. That’s the end of the tail.
>> Rick Crosslin: You don’t have to come all the way to South Dakota to find
fossils. In fact, back home in Indiana, you can find fossils that are even older than
dinosaurs.
At one time, there were dinosaurs in Indiana, but their remains were scraped
away by huge moving sheets of ice called glaciers. Now, the only dinosaur bones
you’ll find are here in the Dinosphere at the Children’s Museum of Indianapolis.
However, glaciers did grant us access to the layers below that contain fossils of
the earliest life on Earth. To learn more, we visited with Dallas Evans who had
some interesting fossils to show us.
>> Rick Crosslin: So Dallas, we’re here back at the museum, and we just spent a
long time on dinosaurs. There’s no dinosaurs here, but Indiana has some pretty
special fossils. Do you agree?
>> Dallas Evans: We have some pretty spectacular
things in this state, yup.
>> Rick Crosslin: What do you have here to show us
today?
>> Dallas Evans: Well, when we dig dinosaurs, what we dig are things that are
65 million years old. In Indiana we have a lot of things that are 300 million years
old plus. So all of these are Paleozoic fossils, far older than dinosaurs that we
dig. All from Indiana, lovely things like this isotelus trilobite. This comes from
Madison, Indiana. And also from Madison, Indiana is this little flexiclemni trilobite.
This gorgeous little Paleozoic creature. We also have brachiopods, basically
shell fossils from Indiana; Gastropods or snail fossils.
>> Rick Crosslin: This looks just like a snail in our backyard. So these are very
similar I guess.
>> Dallas Evans: Very similar; you could pick one up and it’s hardly distinguished
from one in your backyard. These however are marine specimens so they’re
ocean animals.
>> Rick Crosslin: 300 million years ago, Indiana was
at the bottom of a shallow ocean. It was this ocean
and its sea life that created the limestone deposits
that Indiana is known for today. And within this
limestone is a fossil that Indiana is famous for
around the world.
>> Dallas Evans: If you’re in Indiana, this is what you want to look for. They’re
beautiful specimens. They’re called crinoids. They used to be called sea lilies,
but that’s a bit off a misnomer. They’re not really plants. They kind of look like
plants. But it’s actually, essentially a starfish with a stalk. It’s an echinoderm. And
it’s a filter feeder. This little head would kind of open up and filter feed.
>> Rick Crosslin: So this guy’s kind of on a stalk and the head of it, or the calyx,
is a filter feeder. So when most people see this they would think, ‘Oh, that’s a
plant’
But actually, it’s an echinoderm which is an animal, because it has the ability to
move. Now most of the time, when I’ve been out with kids, we find pieces of
these that look like little, bitty Cheerios. So what part is that on this?
>> Dallas Evans: That’s actually a stem section. These are actually very, I don’t
know another word for except for breakable animal. Once they died, the skeleton
was very fragile. So wave action or another animal going nearby would just break
them apart, shatter them. And you get all these little columns, these bits of the
stem would break apart and you find little sections that well, look like Cheerios.
Museums the world over come to Indiana to try and find these crinoids. We have
some of the best known deposits in the world.
>> Rick Crosslin: In fact, I think the state fossil is a
crinoid.
>> Dallas Evans: Perfect, yup.
>> Rick Crosslin: It’s synthocrinides
mutlibrachiodus.
>> Dallas Evans: You get an A+ for the day. That’s
perfect.
>> Rick Crosslin: And these brachiopods right next to it are beautiful. But I have
to ask you, this is a strange looking thing and is that a dinosaur? Is that a marine
fossil?
>> Dallas Evans: I actually love this piece. It comes from Shelbyville. And when
people bring it in or when people see it, they automatically assume that it’s a
dinosaur. But actually it’s much later. It’s from a large mammal. It’s from a
mammoth.
>> Rick Crosslin: A mammoth.
>> Dallas Evans: It’s a mammoth tooth, a single molar from a mammoth.
>> Rick Crosslin: And that’s from Indiana.
>> Dallas Evans: From Indiana.
>> Rick Crosslin: But these are very old and dinosaurs are very old, but these
are relatively new.
>> Dallas Evans: Actually pretty young. It’s Pleistocene. That’s an era that’s 2
million to about 15000 years ago. So this is at the very end of the Pleistocene. So
it’s in thousands of years instead of millions like we’re used to.
>> Rick Crosslin: So not all Indiana fossils are sea animals. Indiana was
inhabited with giant land animals only a few thousand years ago. These fossils
are rare and can be hard to find. But you can find your own Indiana fossils
wherever you see layers of limestone.
>> Rick and Kids: This is science! Try it yourself!
>> Rick Crosslin: I recently scooped up some rocks near the road and brought
them to my science camp. You’d be surprised what you can find in a pile of
rocks. I invited a group of second graders from Saint Monica School to join me
on the world’s smallest field trip.
You could spend a week studying and finding all the things that are on this piece
of limestone. There’s crinoid stems.
>> Kid: Look at this! Oh cool!
>> Rick Crosslin: You can find many different types of Indiana fossils: crinoids,
trilobitesThat is the head of a trilobite.
-gastropods, and even brachiopods.
This is like a fossil zoo.
But it’s what we don’t see that can be the most important find we ever make:
microfossils.
You know microfossils are everywhere in Indiana, under your feet, under your
fingernails. But when you find some cool microfossils, we stop here at the
Children’s Museum to talk to William Ripley. He is our expert on things that are
small. Hey William, how are you doing?
>> William Ripley: I’m good. How are you?
>> Rick Crosslin: We’re here with these really small fossils at the museum. This
one right here just has to be the flake of a bone. What in the world is that?
>> William Ripley: What we have right here, this is
actually a part of a fish jaw.
>> Rick Crosslin: A jaw.
>> William Ripley: A jaw, yup.
>> Rick Crosslin: That’s only, that’s not even a
centimeter large.
>> William Ripley: No it’s not. And if you look really
closely, you might even be able to see the teeth in it.
>> Rick Crosslin: Oh yeah. I guess a microscope helps with microfossils.
>> William Ripley: Hence, microfossil.
>> Rick Crosslin: Now a microfossil, what is a microfossil used for?
>> William Ripley: There’s a few different things they can be used for. Index
fossils, that let’s us show how the world has expanded, plate tectonics.
>> Rick Crosslin: So if you go to the library and you go to an index file, you know
that these numbers, books go here. So is a fossil like that, an index fossil?
>> William Ripley: Pretty much, yes, yeah.
>> Rick Crosslin: So if you find a small little fossil and you know that that was in
this layer of rock and you find that same fossil somewhere else in the world, what
does that tell us?
>> William Ripley: It gives us a basic age so that we know everything you find in
that layer is the same age as everything you’d find in a layer farther away.
>> Rick Crosslin: So microfossils are important for that. So what other uses are
they?
>> William Ripley: They can help fill out the environment. They let us know what
other types of animals were around. We have the big animals. These tell us the
smaller animals.
>> Rick Crosslin: Can you tell climate? How could you tell climate about them?
>> William Ripley: By what types of animals you find. For example, that is a
crocodile scoot. Crocodiles are found only in certain climates. So we can gauge
what type of climate there was where this was found.
>> Rick Crosslin: So this is almost like a list of all the animals in an ecosystem.
>> William Ripley: Exactly. You’re right.
>> Rick Crosslin: These seem like they would just blow away. So how do you
find something like this?
>> William Ripley: We take the rock and the dirt that
come in with the fossils, and I soak it down. I usually
soak it for about a week in water. I run it through
screens, basically like screens you would find in
your screen door. And that washes all the dirt away.
And what’s left are these little pieces. And then I let
them sit for a few days, dry out. I collect it, that’s
what’s called concentrate. I concentrated everything
down. And then I put it under a microscope. You can have an entire museum in a
shoe box basically.
>> Rick Crosslin: That’s great. I tell you, big fossils, medium sized fossils,
microfossils. William Ripley, thanks a lot for taking just a little bit of time to show
us these little fossils.
>> William Ripley: My pleasure.
>> Kid: Did you know that the layers of rock in Indiana are kind of like a
sandwich?
This knife represents a glacier. All that’s missing is Lake Michigan.
>> Rick Crosslin: Right about here.
>> Rick Crosslin: You know I do love looking for fossils. But what I like even
more is sharing what I find with kids just like you.
I took the samples we collected to South Elementary in my hometown of
Danville, Indiana. I stopped in on my friend Jenny Woodward’s 4 th grade class.
Using the sifting techniques we learned from William at the Children’s Museum,
we found some microfossils, placed them in our homemade slides, and studied
them with a microscope.
We discussed the importance of studying fossils.
Afterwards it was time for a lesson from Miss Woodward. Miss Woodward is a 4
th grade teacher at South Elementary.
>> Jenny Woodward: We have an ‘Aha’ science
moment every single day in this room. I learn
something new with every unit.
>> Rick Crosslin: This is here first year as a teacher.
Today, she’s teaching a lesson on natural resources
and fossil fuels. And these students are going to do
a little mining, not for gold or coal, instead they’re mining something delicious.
The cookie represents the earth or the ground and the chocolate chip is the
resource. And as you can see it’s very difficult to remove the resource without
destroying the ground. This gives us a little insight how important and careful we
must be when extracting the earth’s resources.
>> Jenny Woodward: We also talked about the importance of conserving as
much energy as we can. You can’t get it back. When we use it all up, it’s gone.
>> Rick Crosslin: Another neat thing about science is you can learn things, you
can make discoveries, and you also have some good cookies too. Mmmmm. I
think that’s the best part of science. I’m not sure.
>>Rick Crosslin: You probably won’t find chocolate chips out here. But there is
another natural resource: coal.
Coal is a fossil fuel found at differing depths in the
Earth’s crust.
I’m in a pretty unique place here in Indiana. We’re in
the bottom of a coal mine and I’m standing on coal.
It’s the result of prehistoric plants and animals being
compressed over millions of years, just like the sandwich earlier.
Behind me you can see the different layers of rock. If you look carefully, you can
actually see the topsoil, the subsoil, and then below it this large gray area called
shale, otherwise known as mudstone. Yup, tastes like mud. The gray shale is
pretty interesting. There’s actually fault lines, a natural process. But if you look
carefully, you can see this black layer going right here. That’s a coal layer and it’s
actually valuable and thick enough to be mined. Mining coal is a cool business.
All of this is actual money falling through my fingers right here. Because when
you get to this part of the mining operation, this is where all the black gold is
ready. Layers of coal ready to be scooped up, hauled up, processed and sent on
its way to power plants all across the Midwest and Indiana.
It just so happens that this material is a combustible energy source. In fact,
burning coal is one of the many ways we make electricity.
(MUSIC)
>> Rick Crosslin: The goal of the coal is to have a pile this big. This pile right
here would heat our homes for a long time in Indiana.
It takes a lot of effort to get this stuff out of the ground
and even more work to get the ground back to the
way it was before the mine was here.
It’s called a strip mine, because they strip the soils,
and they save it to reclaim it. Now behind me, it looks like a regular Indiana field,
and they’ve worked really hard here to make that a reality.
This is George Boyles and he is in charge of getting the land back in shape after
the coal has been extracted. His team works to put the environment back
together after it’s been taken apart.
>> George Boyles: It’s quite a shuffle to get all of that back.
>> Rick Crosslin: Back in South Dakota, it’s a little
easier. Here you can find the coal right on top of the
ground, because nature does the strip mining for us
through a process called erosion. Erosion occurs
when a force like water, moves sediment, which is
mud dirt and sand, over the Earth’s surface. As time
goes by, erosion can do some amazing things. In
Indiana, you can see the effects of erosion. And one of the best places to see it is
inside a cave. A cave is a natural underground cavity, or a hole in the ground.
There are many kinds of caves: Lava tubes, sandstone, ice and even sea caves.
But roughly 95% of the world’s caves are limestone, the same stuff that Indiana
is made of.
Hey, we’re at Porter’s Cave, a great example of sedimentary rocks and erosion.
Let’s go check it out. Come on!
Porter Cave is a limestone cave. The study of caves
is called Speology. Today, this group of kids and I
are going spelunking, which is just a fancy way of
saying caving. The first explorers of this cave used
torches and candles to light the path. I truly enjoyed
reliving the path blazed by the first explorers of this
cave.
If you hold up the candle high, you can actually see some of the formations on
here. That’s beautiful. Can you imagine what it’s like to explore a cave just by
candlelight? It’s kind of fun really if you ask me.
>> Kid: No it’s not. It’s very creepy.
>> Rick Crosslin: It is a little creepy.
>> Kid: Are we almost out?
>> Rick Crosslin: No we’re going the other way.
>> Kid: Why?
>> Rick Crosslin: Luckilly, we now have flashlights. A cave like this is formed
when rainwater absorbs CO2, carbon dioxide,from air and the soil. As it seeps
down, it becomes a weak acid that dissolves limestone. The cave is formed by a
chemical reaction, but also a physical reaction. Over hundreds of years, the
flowing water erodes away the limestone and carries the sediments along the
water’s path, turning the water into a natural sanding machine.
This passage was formed by water that carved through the solid rock. Erosion,
happens above ground and underground.
Now it may seem like this process is only about
removal. But as it turns out there is also a
process of building going on inside the caves.
And this building produces some fantastic cave
formations. Limestone is made of the mineral
calcite. As the acid-water dissolves the
limestone, it picks up calcite and other minerals.
Under the right conditions, the mineral-rich water
will evaporate, leaving behind something new to the cave. Inside a cave, this
process takes millions of years, but it’s worth the wait. The result is a fantastic
cave formation. The most common are stalactites that hang from the ceiling and
stalagmites that grow up from the cave floor.
(MUSIC)
>> Rick Crosslin: Cave exploration is a great way to witness the power and
beauty of nature, but it can be risky business. If you go caving, be careful and go
with a grown up. Remember to watch your step, because a crack in the ceiling
means a crack in the floor. And make sure you take nothing but pictures and
leave nothing but footprints. For more information on caves and what you can do
to preserve them, go to wfyi.org.
>> Kid: Did you know that wind cave in South Dakota is one of the longest caves
in the world? It’s only about 5 hours away from the Ruth Mason Quarry, the
location of our dino dig.
>> Rick Crosslin: These fossils have been buried
underground for millions of years. The soil above
them and the rocks have protected them from the
sun and wind and animals. As soon as they’re
exposed through erosion, it’s a race to save them,
because they will disintegrate back into dirt and
dust. They way we do this in the field is by putting a
jacket around them made of plaster, aluminum foil,
and wood for support. Carefully covering these fossils allows us to flip them over,
finish the job, number them, and send them back to the lab for final preparation.
After we get these fossils out of the ground and back home to Indiana, the real
work will begin.
>> Dallas Evans: The amount of time it takes is extraordinary. If you have a small
bone and it only takes three or four hours to dig, it will take you a couple of
weeks to prep back in the lab.
>> Rick Crosslin: So Victor, we’re finally back in the museum in the Paleo Prep
Lab, and now the real work starts. So what do we have here in front of us?
>> Victor Porter: What we have here this morning is
we have a femur and a wonderful ischium.
>> Rick Crosslin: A femur and an ischium. And were
these dug by museum staff?
>> Victor Porter: Actually they were dug by two young
gentlemen, two young boys.
>> Rick Crosslin: So at the Children’s Museum, not
only do teachers go on digs, but kids and families go on digs.
>> Victor Porter: This is one we worked on as soon as we got back. This is the
fibula that you might have seen, the long limb bone.
>> Rick Crosslin: Someone has done some excellent work restoring this. So
Victor, how many bones did you find?
>> Victor Porter: Well this year, we actually found 118 bones. This will fill our
year until we go back next year.
>> Rick Crosslin: I tell you what, I’m gonna let you go ahead and get busy
prepping these bones. Good luck. I can’t wait to see how these things turn out.
>> Victor Porter: Thank you.
>> Rick Crosslin: Good Job.
>> Victor Porter: Once the fossils come back to Indiana, we use dental tools,
epoxy to consolidate them. We remove all the rock down to the bone. We use an
airbrater. Using baking soda, we’ll basically sandblast them down to the
chocolate brown. The bones that we’re finding in quarry B are very good quality.
You basically clean the rock off of them and they’re done. There aren’t any
pieces missing on them. They’re just the way you see them. You do what you
can, and that’s what we do.
>> Rick Crosslin: Thanks to the men and women in the Paleo Prep Lab who
pieced together these prehistoric puzzles, we can enjoy full size dinosaur
skeletons. In Earth Science, whether it’s big science or little science, it’s all
important science. It helps us learn about the past. I’m Rick Crosslin, join me on
the next Indiana Expedition. See you outside!
>> Announcer: Indiana Expeditions with Rick Crosslin is made possible through
the generous support of:
The Doctor Laura Hare Charitable Trust, enhancing Indiana’s natural
environment through preservation and protection of ecologically significant areas
and promoting environmental education, stewardship, and awareness.
SEFI, the Science Education Foundation of Indiana, investing in Indiana’s youth
by encouraging them to become scientists and engineers and to practice their
careers in Indiana. Details at SEFI.org.
And the Center for School Improvement and Performance, Indiana Department
of Education.