Paleontologist Kirk Johnson shows a group of high schoolers that plant species in Virginia used to be right at home near the North Pole.
Plant Fossils Hint at Arctic's Swampy Past
Published: January 30, 2020
Onscreen: This Virginia swamp holds clues to what the Arctic looked like 56 million years ago.
Paleontologist Kirk Johnson shows local high schoolers how to read the leaves.
Kirk Johnson: This is our first plant.
Anybody know what this one is? This is sycamore leaf. Let’s go on.
So, what do you see?
Student #1: I see the veins.
Johnson: Yeah, they’re tiny, right? This is a conifer. This is called bald cypress.
Here you go, what do you think about this leaf?
Student #2: It looks like they have five main branches.
Johnson: The common name is sweet gum.
Student #2: Oh, ok.
All right, here you go.
Do you know what this thing is?
Student #3: Um, not really.
Johnson: What this is is a walnut tree.
Student Crowd: Oh.
Johnson: I have a bag full of fossil leaves. Half the leaves come from northern Alaska and half the leaves come from Ellesmere Island. The first one is this one.
Ok, this is kind of a cool one. This is from Alaska. You can see there’s a whole bunch of leaves on it. It’s kind of like leaf litter.
How does that do for you here with your stuff, Jaden?
Student #1: Uh, it matches with like this…
Johnson: Yeah, like that one’s a pretty good match
But here’s an Alaskan plant in Virginia.
Here is a big old leaf. Does it look like your plant?
Student #4: Yeah
Johnson: Yeah, it’s a pretty good match, isn’t it?
Student #4: Yeah, very close. It’s got the same sort of veining patterns.
Johnson: Yeah, and this is almost a 100 million years old. And that’s about an hour from being picked.
Ok, now let’s see what else we got. I think I need to pass this one down to you and see if you can get a match on this one.
Student #5: All right. It looks like it’s the same shape, broad that the base and then narrow at the top.
Johnson: Are you comfortable with that being a birch?
Student #5: Yeah, it looks like it could be.
Johnson: That’s the exact right answer. So now we got Arctic fossils of birches, sycamores, bald cypresses.
You’re starting to see what I saw when I went to the Arctic, which is, “What I’m seeing here looks just like what I see in the swamps of Virginia.” Which is kind of weird, if you think about that.
Onscreen: This forest is home to the remnants of a once-continuous forest that ran across the Arctic.
Fossils of all these trees have been found in the Arctic:
Johnson: Then as the climate got cooler, the forest couldn’t survive in the Arctic areas. But the remnants of those forests live here in eastern North America and in China. You have your living relics of a once continuous Arctic forest.
Director: Lucy Haken
Assistant Producer: Sacha Thorpe
Camera: Piers Leigh
Sound: Josh Forwood
Digital Producer: Ana Aceves
Additional Footage: Yale Peabody Museum of Natural History
© WGBH Educational Foundation 2020