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Hi, I'm Ranger Myra from
Hopewell culture National Historical Park
in Chillicothe, Ohio.
Have you ever taken a walk outside
and found a rock and wondered
"is just a rock or could it be something else?"
If it looks like an animal or a plant
or even the tracks of an animal,
chances are it could be a fossil.
Throughout human history,
humans have been fascinated by fossils.
From the Hopwell that lived here 2,000 years ago
to my kids just playing in our backyard,
fossils have captured our imagination
and made us ask "what is its story?"
So let's explore this connection to the past,
find out how fossils are made,
and learn about the different types of fossils there are.
How do we know American Indians
from 2,000 years ago appreciated or even
noticed fossils?
We know this because Archaeologists
who study Hopewell sites
have found fossils intentionally buried alongside
handmade objects at important burial sites.
Some examples of the fossils that have been found
are parts of a mastodon tusk,
horned coral,
and even Megalodon shark teeth.
Now, the same question that pops in our head
may have occurred to the Hopewell 2,000 years ago.
What is this?
A fossil is evidence of life
that has lived here for a long time ago,
that is preserved in some of the oldest things
we have on earth, which are rocks.
So, how did the fossils get here?
It's actually a matter of being at the right place
at the right time.
When an animal or plant dies,
it has to quickly get covered up
before it becomes someone's next meal.
Ideally, it could fall into body of water
where it settles into the sediment and
over time more and more sediment piles up upon it
and eventually that pressure causes the sediment
to turn to rock, encapsulating that organism.
Water then trickles through the rock
and deposits minerals into the encapsulated area
where the animal was,
and that's how you get your fossil.
Now, in order to get these conditions perfect
it is very difficult, so fossils are very rare.
And to find one is even harder to do.
They also represent only a tiny portion
of the animals and plants
that have ever existed.
Now that we know how they're made,
what types of fossils are there?
In general, we have four types of fossils.
There's mold fossils, cast fossils
trace fossils, and true form fossils.
The mold fossils are generally formed
when sediment surrounds the animal
and forms a imprint of the animal.
So they're usually hollow.
Examples of these types of fossils are
the skin of animals,
the teeth and the claws,
and sometimes the leaves of plants.
The cast fossils come after the mold fossils.
What happens is after the mold fossil
has been formed and hardened,
the cast fossil comes in and
fills in that hollow mold
and forms a solid form of the same imprint.
So can have, again, skin, claws, feathers,
and leaves of animals and plants.
The third type of fossil we have are trace fossils.
Or, also known as ichnofossils.
These are really important because
they give us an insight into how the animal lived.
So examples of this type of trace fossils are
the tracks of animals, the burrows they lived in,
the nest that they might have lived in,
and even coprolites, which is the dung
that they leave behind that has been petrified.
The fourth type of fossil we have are
true form or body fossils.
This is usually what people think about
when they hear the word fossil,
they think of dinosaur bones.
So what happens with the dinosaur bone
is that bone itself is replaced entirely by the minerals
and has become hardened and petrified
Examples that we have in Ohio is the
state fossil that we have, the trilobites,
we have horned corals,
and we also have brachiopods.
Keep an eye out for these different types of fossils.
Your backyard is a great place to investigate.
Fossils have captured our imagination throughout time,
and perhaps you'll learn their story
and share with others.
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