How do you find dinosaur fossils?

AKI WATANABE (Research Associate, Division of Paleontology, American Museum of Natural History): How do you find dinosaur fossils?

[Watanabe speaks to camera. Text reads: “How do you find dinosaur fossils?”]

[MUSIC] [BOOM]

[The American Museum of Natural History logo appears, with text below it reading “Space Vs Dinos” superimposed on illustrations of an asteroid and a dinosaur skull. Watanabe reappears, with text: “Aki Watanabe, Paleontologist”]

WATANABE: Discovering a dinosaur fossil is one of the most exciting parts of being a paleontologist.

[A circle draws in on the left of Watanabe. In it, up pops a dinosaur skull and bones.]

WATANABE: But it also takes a lot of preparation and hard work.

[The skull and bones disappear and are replaced with illustrations of field equipment: a bag, a hammer, a jackhammer, a compass, a flashlight.]

WATANABE: So the first step is for the paleontologist to figure out where to dig for fossils.

[A globe appears in the circle with a question mark over it. The whole screen is pushed away by a blue screen with the word “sedimentary” written in the middle.]

WATANABE: The region has to include sedimentary rock layers,

[The word sedimentary blends into the background of striated rock.]

WATANABE: like limestone or sandstone

[A circle pops up with a limestone sample in it, and text on top reads “limestone”. A circle pops up with a sandstone sample in it, and text on top reads “sandstone”.]

WATANABE: because those are the rocks that contain fossils.

[Both samples pan to different areas of the samples where there are clearly fossils embedded within.]

WATANABE: These sedimentary rock layers need to be exposed on the surface

[Text appears on the illustrated striated rock, where the first half, “exposed on” seems to be exposed on the surface, while the second half “the surface” is kept hidden below.]

WATANABE: so that the fossil bones are on the ground where paleontologists could easily pick them out.

[Camera pans over the surface and we see some bones scattered on or near the surface. A machine claw comes down and plucks one of the bones out of the ground.]

WATANABE: The sedimentary rock layers need to have been formed while dinosaurs were alive,

[The surface of the ground moves up so half the screen has dinosaur bones and half does not. The half that does has brackets around it that contain the text “formed during the age of dinosaurs.” The half that doesn’t has brackets around it that contain the text “formed earlier than that.”]

WATANABE: so that would be between about 230-66 million years ago.

[The top bracket’s text is replaced with “230-66 million years ago.” The bottom bracket’s text is replaced with “not then.”]

WATANABE: So if a region ticks all these three boxes, then there's a good chance that you'll find some dinosaur bones in the area.

[The camera pans up and a checklist appears. Each item on the list is checked off in succession: “sedimentary rock,” “that is exposed,” “and the right age.” A box draws in around the checklist and the checklist disappears to show a checkmark next to a dinosaur skull. The camera pulls back and we see similar boxes popping up all over the world. Watanabe appears on screen again]

WATANABE: So once you've made the decision on where to look for fossils, then it's time to actually start your fieldwork.

[A human figure drops from the top to an X on the ground. The human catches a rock hammer that drops from the top and sparkling confetti races out from behind the human.]

WATANABE: The first phase is called prospecting

[Text appears: “Prospecting.”]

WATANABE: where all of us would just stare at the ground for miles and miles and hours and hours until we find fragments of bone on the ground.

[Footage of a paleontologist from their perspective picking up bone, bordered by a simple red border with the text below: “Paleovision.” Camera returns to Watanabe.]

WATANABE: And we walk with this magnificent tool called the rock hammer.

[Watanabe holds up a rock hammer, which looks like a regular hammer but slightly longer and pointed at one end. Lines draw out from the rock hammer and text appears on screen: “rock hammer.”]

WATANABE: So, when we do find fragments of bone sticking out of the ground, then we can use it to either take it out of the ground and also to dig a little further to see if there are any other bones nearby.

[More footage of a paleontologist digging in the earth with a rock hammer.] 

WATANABE: A lot of people might think that when you're looking for fossils you might see whole skeletons

[With a [glockenspiel chime] the full body of a titanosaur specimen rolls out across the bottom of the screen in front of Watanabe.]

WATANABE: but typically what you find are fragments and very damaged pieces of bone

[Many of the bones in the titanosaur fall offscreen.]

WATANABE: like this one here.

[Watanabe holds up a broken, porous-looking piece of rock.]

WATANABE: So one of the important skills for paleontologists is to be able to tell apart fossil bone from regular rocks.

[Text reads: “Fossil bone vs regular rock”.]

WATANABE: And so we look for features like grain texture on the surface

[Watanabe indicates the vertical grain on the outside of the fossil he is holding. Text reads “Grain texture”.]

WATANABE: and also internally there should be holes where blood vessels and bone cells used to be.

[Watanabe indicates the porous-like material on the inside. Text reads “holes inside.” Watanabe reappears on screen.]

WATANABE: Paleontologists can learn a lot from just little bits of bone.

[Drawn image of a piece of bone appears in a circle.]

WATANABE: We can learn about how the dinosaur grew,

[Two other images of fossil bone fragments appear in their own circles. Text reads “Growth”] 

WATANABE: or what the overall size was,

[New text reads “Size”]

WATANABE: and in a lot of cases, we can tell to which group these fossils belonged to.

[Over each of the three images of a bone fragment, we see a silhouette of the dinosaur it belongs to: an ankylosaur, a hadrosaur, and a megalodon.]

WATANABE: So this is a piece of bone from a duck-billed dinosaur.

[Next to an image of the piece of bone Watanabe was holding, the image of the duck-billed dinosaurs on display at the Museum. Watanabe reappears on screen. 

WATANABE: Once you find some dinosaur fossils

[A magnifying glass moves around next to Watanabe, revealing fossils.]

WATANABE: then you're ready to move on to the next phase of fieldwork which is called excavation.

[Text appears: “Excavation”]

WATANABE: And this is where you dig out the fossil bones.

[“Paleovision” border returns, showing hands scraping dirt away from bones.]

WATANABE:  But at this point you are not interested in taking out the bones individually

[Watanabe appears on screen again. Next to him, a cartoon of a human figure approaching a bone embedded in a rock bed. The human picks up the bone.] 

WATANABE: because a lot of the fossil bones will be fragile.

[The bone easily falls apart. The human figure [SCREAMS]].

WATANABE: You'll be taking out the bones with the surrounding sediment

[“Palevision” returns. We see the paleontologist drawing a generous outline around the bones in the soil. Then we see paleontologists covering a huge chunk of land with toilet paper in order to safely ship it.]

WATANABE: and then shipping it to a lab so that you can prepare it using specialized tools.

[In “Paleovision” we see hands using a drill to chip away tiny bits of rock from a fossil. Watanabe appears on screen again.]

WATANABE: So the steps involved in fieldwork hasn't really changed in over a century

[Two bubbles appear next to Watanabe. One with black and white footage of a man excavating a fossils (text beneath reads “1925”), the other has color footage of a woman excavating fossils (text beneath reads 2018).]

WATANABE: although a lot of the techniques for analyzing dinosaur bones have changed quite a bit, even in the last decade. And finding fossils still takes dedication and determination, a little bit of luck, and also knowing what to look for.

[Next to Watanabe, these things appear on a list (in order):

WATANABE: Right now there are paleontologists digging up dinosaur bones on all seven continents.

[A world map fills the screen with sweeping brushes on every single continent.] 

WATANABE: And so this might make some people worry that there will be a shortage of dinosaur fossils in the future. But we’re finding more and more fossils, and there’s no sign of it slowing down.

[A few fossil fragments rain down behind Watanabe.]

WATANABE: For me it’s the best part of being a dinosaur paleontologist.

[A human figure appears to the left of Watanabe and holds up a giant T. rex skull, with confetti and streamers behind him.]

[Credits roll. Watanabe plays in the lower right hand corner of the screen.

WATANABE: Thanks for watching the video. If you’d like to see more videos like this, hit subscribe, and also if you’d like to see this week’s space video, click the link above. And if you have any questions about dinosaurs, leave them in the comments section below.