Videos

[MUSIC]

[The skull of a titanosaur appears.] 

NARRATOR: What is a fossil, 

[Two images appear side by side: the white skeleton of a fish and the dark brown fossil of a similar-looking fish.]

NARRATOR: –and how is it different from just a regular skeleton? 

[ROGER BENSON appears on screen, speaking to the camera.] 

BENSON: A fossil is any remnant of past organic life. 

[Two large fossil femur bones appear, and a photo of a large fossil Megalodon tooth appears next to them.] 

BENSON: So for example, a bone or a tooth.

[The images of the bones and tooth move down and are replaced by video of a bumpy surface, with a label that reads “skin impression.”] 

BENSON: But also any trace that it left in the sediment.

[The skin impression is replaced by a large, three-toed footprint impression in a rock.] 

BENSON: Dinosaur’s footprints are fossils, 

[A rock filled with holes appears, with a label that reads “fossil burrows.”]

BENSON: –or the trackways of other animals. 

[A black-and-white image of a fossil leaf on a rock, and an image of a lot of empty shells embedded in rock appear.] 

NARRATOR: There are fossilized plants and shells,

[A pipette draws a pink liquid in a lab.] 

NARRATOR: and even fossilized chemical traces of past life. 

[BENSON reappears on screen.] 

BENSON: Also fossil poop, of course. [LAUGHING]

[The camera pans down quickly on a large fossil coprolite, or poop, in a collections space.] 

NARRATOR: Yup, there’s even fossil poop.

[The American Museum of Natural History logo appears. The coprolite or poop is replaced by the AMNH Tyrannosaurus rex on display in the halls.]

NARRATOR: A fossil bone–

[We take a closer look at one of the T. rex’s leg bones. Text appears: “fossilization.”] 

NARRATOR: –has typically undergone a process called fossilization–

[Camera focuses on a fossil tooth or claw still in the ground.]

NARRATOR: –between when the animal died, 

[A birds-eye drone shot of paleontologists at a fossil quarry, digging and removing dirt from the area.] 

NARRATOR: –and when the fossil was found by today’s paleontologists. 

[BENSON reappears on screen. Text appears: “Roger Benson, Macaulay Curator, Division of Paleontology.”] 

BENSON: So fossilization typically involves original mineralized parts of organisms like shells and bones. 

[An image of an okapi skull in a collections space appears next to an image of a few cone snail shells. Text below the images reads: “biomineralized animal parts”] 

BENSON: And those are mineralized structures in the original animal, 

[The images of the skull and shells are replaced with images of beetles eating at a skeleton carcass and an image of someone holding empty shells on a beach.] 

BENSON: –so they don’t decay after death, but they often get a bit altered. 

[Water drips through an overhanging rock.] 

BENSON: Through time, water’s flowing gradually through the rocks.

[Next to the image of water on rocks, a photo of a cross-section of a bone appears, with a spongy texture filling its interior.]

BENSON: Bone is a really porous, spongy material,

[Text appears, pointing to the spongy interior of the bone: “minerals deposited here”.] 

BENSON: –and waters deposit new minerals inside all of the void spaces in the bones.

[The image of the bone cross-section minimizes, and a new image showing a rock with an impression of a shell inside appears.] 

NARRATOR: Or the water may dissolve a bone or shell completely,

[The image of the shell impression zooms out, and we see the opposite side of the rock, where a cast of the shell appears.]

NARRATOR: and deposit new minerals in the same shape, 

[The shell fossil disappears and is replaced by a pearly iridescent ammonite fossil.] 

NARRATOR: like a mold and a cast. These new minerals are– 

[A large, dark grey fossil is placed next to two white bones, with a label pointing to the white bones: “normal bone”.]

NARRATOR: –the reason that a fossil might be a completely different color,

[A label points to the grey fossil: “fossil bone”.] 

NARRATOR: –like brown or green, instead of white. 

[The camera pans from a box of brown-colored fossils to a box of slightly blue-colored fossils.] 

NARRATOR: So after this process, fossils are basically just rocks– 

[Pan across a green jaw fossil with teeth, which are also bright green.] 

NARRATOR: –which can sometimes make it hard to tell them apart from– 

[A row of fossil bones, which are each half dark brown and half white in color.] 

NARRATOR: –all the other rocks you might find at a fossil site.

[BENSON reappears on screen, speaking to the camera.] 

BENSON: In fact, I’m sad to say that I’ve sometimes collected things I thought were fossils that turned out to be some other minerals that were the same colors as fossil bones.

[Paleontologists’ hands inspect rocks, looking for fossils.] 

BENSON: So some of the key things we look out for is, firstly, does it really– 

[A fossil bone still in the ground is outlined in pink, and a drawing of a bone overlaid on top of it.]

BENSON: –look like a bone, as in is its structure similar to the structure of bones. 

[BENSON reappears on screen, speaking to the camera.] 

BENSON: And if it really looks nothing like a bone, then it probably isn’t one. 

[Closeup of fossil bones, showing a spongy, textured appearance.]

BENSON: That spongy texture of bone can cause it to stick to people’s tongues.

[BENSON reappears on screen, speaking to the camera.]

BENSON: So some paleontologists like to lick the bone and see how sticky it feels to them. Myself, I don’t like this technique very much.

[The camera pans from tail to nose of the Tyrannosaurus rex specimen on display at the American Museum of Natural History.]

NARRATOR: And while you might think it would be pretty hard to miss a full T.rex skeleton lying out on the sand, remember that most of the bones that made up an animal don’t actually make it to the fossilization process.

[BENSON reappears on screen, speaking to the camera.]

BENSON: After an animal dies, its remains might be around on the surface for quite some time before it’s buried by sediment. And in that time, lots of different things can happen.

[Footage of an animal skull lying in a river, and footage of a hyena running from a kill site with a leg bone in its mouth, appear.]

BENSON: Like it can be washed around by waters, or it can be interfered with by scavengers. So what that means is–

[The footage is replaced by an illustration of a carnivorous dinosaur as it might have looked in life, tearing flesh off of a carcass.]

BENSON: –many of the fossil remains of past animals that we find are–

[An older display of fossils in Museum halls shows just a skull and some vertebrae.]

BENSON: –just parts of the animal. So there might be–

[An image of a single fossil tooth appears next to a single fossil vertebra.]

BENSON: –one bone or one tooth or–

[An image of a partial jaw bone appears.]

BENSON: –even just part of one bone.

[BENSON reappears on screen, speaking to the camera.]

BENSON: It’s actually quite rare that we find complete skeletons, and we’re lucky to find even most of the skeleton or half of the skeleton.

[Footage of a fossilized squid impression.]

NARRATOR: And all those other types of fossils that don’t contain hard parts–

[A magnifying glass focuses on a small piece of fossil mosasaur skin.]

NARRATOR: –chemicals, fossilized muscle or skin,

[Camera pans over fossil footprints in a row.]

NARRATOR: –or footprints–are even more rare. But when we do find them,

[Footage of fossil dinosaur eggs.]

NARRATOR: –they tell us so much that a skeleton by itself, can’t.

[We focus in and out on a fossil cast of Archaeopteryx.]

BENSON: In dinosaurs, this has been particularly exciting, because we have–

[Two images of fossil dinosaur feathers appear. One looks like the outline of what we might expect a bird feather to look like, and one looks more wispy, like hair.]

BENSON: –fossil dinosaur feathers. And this tells a lot, you know?

[An image of a dinosaur fossil with the impressions of bird-like feathers surrounding the bones.]

BENSON: Dinosaurs weren’t just scaly reptiles, they’re related to birds.

[An image of a fossil claw with sharp, curved claws appears. Circles draw on around the pointy claws.]

BENSON: If we’re lucky to get the keratinous sheath of claws preserved, we can know a bit–

[Another image of a different fossil with curved claws.]

BENSON: –about what the appearance of what the actual claws of an animal would have been.

[A piece of translucent amber sits on a light table.]

NARRATOR: Or beautiful amber fossils, formed by mineralized sap–

[A scorpion inside a piece of amber.]

NARRATOR: –from trees, can show us fully preserved–

[A mantis is suspended in amber.]

NARRATOR: –insects and beyond.

[BENSON reappears on screen, speaking to the camera.]

BENSON: Insect fossils can be quite common in amber, but also things like small reptile scales–

[We see a small piece of amber under a microscope.]

BENSON: –or bird feathers–

[Images taken with a microscope of a beautifully detailed dinosaur feather in a piece of amber, with small flies around it.]

BENSON: –or the feathers of small dinosaurs. And we also very rarely–

[Images taken with a microscope of a lizard, which is mostly just an outline of its scales, but cut-out images show fully-preserved feet.]

BENSON: –have had parts of lizards that are trapped in amber. And this really provides a truly–

[BENSON reappears on screen, speaking to the camera.]

BENSON: –exceptional window into like the remains of animals that we just couldn’t see otherwise.

[Two scientists in full lab coveralls and masks sit at a lab bench in an ancient DNA lab.]

NARRATOR: Today, advancements in science mean we can even find fossilized molecules,

[Two images appear, one of a fossil horse-like mammal and the other to a flat invertebrate fossil. Labels read: “ancient DNA” and “other biomolecules”]

NARRATOR: –like ancient DNA and proteins, expanding the questions–

[A huge fossil leg bone stands upright in a collections space, surrounded by other huge dinosaur bones.]

NARRATOR: –paleontologists can ask about past life.

[In the Museum halls, visitors walk and sit below a fossil mammoth and mastodon.]

NARRATOR: It’s amazing that our dynamic planet–

[Another Museum hall with a fossil turtle and plesiosaur hanging from the ceiling, with visitors passing below.]

NARRATOR: –has preserved so much of the history of life,

[Museum visitors pass in front of a large glass display showing a fossil mammal and rows of fossil Megalodon teeth.]

NARRATOR: –because every fossil is the result of lucky circumstances.

[BENSON reappears on screen, speaking to the camera.]

BENSON: Getting into the fossil record is a little bit like winning the lottery.

[In a collections space, a box of pieces of a fossil are laid out.]

NARRATOR: There are a few things that can improve the chances–

[A paleontologist pulls a large fossil out of a drawer in a collections space.]

NARRATOR: –of a fossil surviving until the present day.

[A beautifully articulated trilobite fossil appears.]

NARRATOR: When this trilobite died, its exoskeleton landed

[Next to the trilobite fossil, footage of a whale skeleton on the ocean floor appears.]

NARRATOR: –on the ocean floor, a place where

[Additional footage of a muddy river waterfall cascading over a cliff, and the mouth of a river shown with sediment flooding out of it from a birds-eye view. Text appears: “places where sediment collects”.]

NARRATOR: –sediment builds up faster than it’s eroded away,

[A skull appears washed up on the banks of a river.]

NARRATOR: –allowing preservation and fossilization to occur.

[The same footage of the original trilobite fossil appears. Beneath it, a counter ticks up to 450 million years.]

NARRATOR: But not only did it become a fossil, but this fossil managed to persist undisturbed in the rocks for hundreds of millions of years.

[The image of the trilobite is replaced by an illustrated schematic showing how two areas of the Earth’s crust are pulling apart, and the land between them is slowly sinking, with new layers being added on top.]

BENSON: If an animal dies somewhere where the earth’s crust is gradually being stretched, that stretching causes the surface to come down–

[Footage of two mountain valleys appear. Text reads: “sedimentary basin.”]

BENSON: –forming what we call a sedimentary basin, where the rocks will survive on Earth’s surface for a long time. 

[Footage of the same original trilobite fossil appears.]

NARRATOR: And voila! Evidence of life from 450 million years ago that scientists can study for many generations to come.

[Credits roll.]