Imagine stepping back in time to a place that’s 52 million years old! That’s what Fossil Lake is like. It’s a special spot where scientists can learn about life during the early Eocene period. Back then, this area was similar to modern-day Florida, with lots of different animals like crocodiles, paddlefish, turtles, shrimp, and even a tiny horse with three toes!
At Fossil Lake, scientists don’t just find the remains of animals; they also find clues about how these animals lived. They discover things like fossilized poop, called coprolites, which tell us what these creatures ate. There are also leaves with insect bites, showing us the kinds of plants and insects that existed back then. It’s like a giant puzzle of ancient life!
On an expedition with the Field Museum, a group of students joined in to help find these ancient treasures. They used special tools like a shim and a hammer to carefully split the limestone rock layers. The goal was to find the “sweet spot” called the 18-inch layer, where most of the fossils are found. This layer is sandwiched between other rock layers that helped preserve the fossils for millions of years.
Once the students reached the 18-inch layer, it was like opening a time capsule. They found fossils of fish, which are the most common discoveries here. Sometimes, they even find rare and surprising fossils that make the dig even more exciting!
During the dig, the students learned how to use their tools to carefully uncover fossils. They tapped and pulled back the rock layers, revealing ancient fish like the Cockerellites, which are shaped like American footballs. They also found Knightia, the most common fish in the area.
Working together, the students and scientists carefully removed the rock around the fossils. They used shovels to lift the rock layers and reveal the hidden treasures beneath. It was a team effort, and everyone was excited to see what they would find next.
After uncovering the fossils, the team carefully collected them to take back to The Field Museum. These fossils help scientists learn more about the ancient world and share that knowledge with everyone.
Exploring Fossil Lake is like going on a treasure hunt through time. Each fossil tells a story about life millions of years ago, and every discovery is a piece of the puzzle that helps us understand our planet’s history.
Imagine you are a scientist at Fossil Lake! Use clay and small objects like leaves or toy animals to create your own “fossils.” Press the objects into the clay to leave an impression, then carefully remove them. Let the clay dry, and you’ll have your own fossil to study. Think about what your fossil might tell future scientists about life today.
Work with a partner to solve a fossil puzzle! Print out pictures of different fossils and cut them into pieces. Mix them up and challenge each other to put the pieces back together. As you work, discuss what kind of animal or plant the fossil might be and what it could tell us about the past.
Create a diorama of Fossil Lake during the early Eocene period. Use a shoebox and craft materials to build a scene with ancient animals like crocodiles, turtles, and the tiny three-toed horse. Include plants and insects, and label each part of your diorama. Share your creation with the class and explain what life was like 52 million years ago.
Participate in a simulated fossil dig! Fill a container with layers of sand and small rocks, hiding toy fossils or shells within. Use brushes and small tools to carefully excavate the “fossils.” As you uncover each one, think about how scientists at Fossil Lake might feel when they find a new discovery.
Write a short story about a day in the life of an animal from Fossil Lake. Imagine what it might have seen, eaten, and experienced. Share your story with the class and discuss how fossils help us learn about the lives of ancient creatures.
**Sanitized Transcript:**
Welcome to Fossil Lake! The area I’m standing in right now is the largest and most complete representation of early Eocene life in the world, about 52 million years old. This area, during the early Eocene, was a lot like what modern Florida is today. You had crocodilians, paddlefish, various kinds of turtles, shrimp, crustaceans, and even insects, bats, and a tiny three-toed horse that was only about 2 and a half feet tall at the shoulder.
Not only do we have the actual animals preserved, but we also have evidence of their behaviors, including their feces, which are known as coprolites. We can tell what they were eating, and we have leaves with insect bites in them. It’s an amazing representation of biodiversity, and there’s nothing else like it in the world today.
So, we’re on an expedition with the Field Museum, which has brought along a group of students to learn the trade and help with the heavy lifting. We’re going to search for some 52 million-year-old fossils!
– Hi!
– Hi, we got our tools now.
– Yes, these are your tools. This is your shim. This is one of the most important tools that we use out here for dividing up the limestone layers.
– So it’s like a wedge.
– Exactly! One end is sharp, and the other end is used for hammering. And this is your other tool.
– A hammer.
– That’s all there is.
It seems that there’s a sweet spot in all the sediment. You’re not consistently finding animals all the way down, like 500 feet.
– Right, it’s a pretty thick layer of rock. But there’s a very thin layer where you have the most fossils. It’s called the 18-inch layer.
– Is that because it’s 18 inches?
– Yes. Above and below the 18-inch layer are what’s called oil capping layers, which helped to preserve the fossils in between those two layers. So that’s the sweet spot. That’s what we’re looking for. Once we hit the oil capping layer, we know we’re at the 18-inch layer. We peel that away first, and then we get to the fossil-bearing beds underneath it.
– It’s like taking a sandwich apart, essentially.
– Yes, take off the bread, and what do you have? Lettuce, tomatoes, cucumbers—I don’t know, I’m not at Subway or anything, but let’s see what we got here.
Well, that’s pretty cool, and you can see stuff at the bottom of this 18-inch layer, which doesn’t seem significant enough.
– It’s amazing. It’s pretty compact limestone. But this 18-inch layer represents several hundred or several thousand years of this lake system’s 15 million-year lifespan.
– That’s incredible!
– This was a very long-lived lake system, and this is only a tiny slice of that ecosystem.
– Because the conditions typically aren’t ideal for fossilization.
– Typically aren’t ideal for fossilization, yes. In this time period, the conditions were ideal, so everything that fell into this lake and sank to the bottom and got buried was fossilized. Everything from microscopic bacteria to mammals, birds, and reptiles.
– That’s fascinating. So we don’t even know what we’re going to find here today.
– We don’t know. Typically we find fish, but every so often we get surprised by something else. That’s what keeps us coming out here year after year for these unusual, rare fossils that you don’t find every day. But it’s still fun finding a fish, because it’s like a fishing trip.
– It’s like a 52 million-year-old fish.
– Unbelievable. Shall we get in our boat and go fishing?
– Yes, let’s go fishing!
– Ready?
– Yes.
– Canoe.
Here we go! If you want to tap away some of that. The trick is to tap and pull back. Get a nice rhythm going. Oh, look! We found a fish already!
– Really?
– Yes.
– Where? Oh, there it is!
– Can you see it?
– Yes!
It’s a Cockerellites.
– How can you tell so quickly?
– We call these football fishes because their bodies are shaped like footballs.
– That makes sense.
– Not a soccer ball though, American football.
– So there’s a backbone.
– Yes. And there’s the football shape right there.
The tail is somewhere here. So the skull is still underneath that rock.
– Oh, okay. Do you have your shim ready?
– Yes, I do.
– Do you have your hammer ready?
– Yes.
– Do you have a name for your shim?
– No.
– You should name your shim.
– It’s Jim the Shim.
– Jimbo.
So we have a crack started on this side already. I’m going to start it, get a little thicker, then you can put your shim next to it.
– Okay.
– You see how one side’s flat?
– Yes.
– One side’s beveled?
– Yes.
– Always have the flat side down because that’ll help push the slab up.
– Wow. So there’s the crack.
– Yes. You’re going to put yours in right about there. Hold it with one hand, hammer with the other hand.
– Like this?
– Just like that.
Next, we go up to the larger tools. This is basically a shovel with a sharpened end on it. So it’s a giant shim. We’re going to use two shovels. This will help separate it even more.
– Alright.
– We’re going to slide the shovels into the crack that we made. So take your shovel.
– Got it. Like right in here?
– Right in there. Ready? Count it out: up, down.
– Okay. Up, down, up, down, up, down, up, down.
– Now stop. Put your shovel in deeper. Count it out.
– Okay. Up, down, up, down.
Now, you see the crack at the end?
– Yes.
– We’ve broken free. Now we can lift it up and see if there are any fossils in there.
– Oh, nice! Okay. So take this?
– Yes, do it by yourself.
– What?
– I’m going to be on the other side, and we’re going to lift it up and point it to the sun so we can see the fossil.
– Alright. So lift.
– Well, there’s some trace material. What is that?
– That’s a branch, actually.
– Oh, alright.
So we just removed the plate and cleaned up around it, so we have a nice, fresh surface here. Now we’re going to move to the left. The goal is to remove all the rock from around this plate.
And you see these mystery feet here?
– Yes, it’s hard to ignore the mystery feet.
– Those are very important mystery feet.
As we’re removing material around this plate that contains fish, if we remove a layer underneath that plate, it’ll pull the plate up and break the fish.
– Oh, okay. So keep your foot down.
– Yes, don’t move. There’s one last piece to get around this fish. Go parallel with the crack.
– So here? Or…
– These cracks.
– Just like that.
– Okay. So now start tapping in.
– Whoa! Alright.
– Wow, that was easy.
– And then I just lift it up?
– Yes, just lift it up.
That was surprisingly easy. So we worked all the rock away from around this plate, so your job now is to go underneath the plate to remove the fossils.
– And just right here?
– Right here for now, but always watch for a crack. Hit it one more time. Oh, you’re there. You see how it’s moving? The whole thing is moving?
– Yes.
– It’s free.
– It’s free?
– It’s free.
– It’s already done?
– Yes, all you need to do is grab one end at a time and lift it up.
– Let’s see. Oh, man, pressure’s on.
– Pressure is on.
– And here. That’s it!
– Hold it up to the sunlight so we can see them really well.
– Oh, you can see them! There they are! What kind of fish are they?
– Those are both Knightia. Those are the most common types of fish that we find out here. Now we’re going to put it into The Field Museum pile and take it back for our collection.
– Cool!
– We did it! There you go. Fishes.
– We’re going to put it on the pile with all the other fishes.
– Let’s set it right there. Yes!
Fossil – The preserved remains or traces of organisms that lived long ago, usually found in sedimentary rock. – Scientists found a dinosaur fossil in the desert, which helped them learn more about how dinosaurs lived.
Lake – A large body of water surrounded by land. – The students visited a lake to study the different types of fish and plants that live there.
Ancient – Belonging to the very distant past and no longer in existence. – The ancient trees in the forest have been standing for hundreds of years, providing a habitat for many animals.
Life – The existence of living organisms, including plants, animals, and microorganisms. – Scientists study life in the ocean to understand how different species interact with each other.
Fossils – Multiple preserved remains or traces of organisms from the past. – The museum displayed fossils of various prehistoric animals, showing how they evolved over time.
Students – Individuals who are studying a particular subject. – The students conducted an experiment to learn about the water cycle and its importance to Earth’s ecosystems.
Tools – Instruments or devices used to perform a task or study something. – Geologists use special tools to examine rocks and minerals to learn about Earth’s history.
Discovery – The act of finding or learning something for the first time. – The discovery of a new species of frog in the rainforest excited the biologists.
Rock – A naturally occurring solid composed of minerals and other materials. – The students collected different types of rock to study their properties and how they are formed.
Museum – A building where objects of historical, scientific, or cultural interest are stored and exhibited. – The class visited the natural history museum to see the dinosaur exhibit and learn about Earth’s past.
