A Chat With the Paleontologist Who Unearthed The World's Biggest T-Rex

The most exciting, confounding movie of this year chronicles a niche news story from two decades ago. Dinosaur 13 is a documentary that delves into the legal, scientific, cultural, and personal dramas that developed when a fossilized, almost fully intact, 65-million-year-old Tyrannosaurus Rex skeleton was found by a group of passionate paleontologists in South Dakota.

The remains were discovered in 1990, when Susan Hendrickson spotted the articulated vertebrate embedded in a geological formation in the Badlands. It took Susan , Peter Larson, and the tight-knit team at the Black Hills Institute of Geological Research 17 days to dig out Sue (her massive namesake). The goal was to turn the old gal into a teaching aid and tourist hub for the citizens of small town Black Hills and the world, but what followed was an epic slog through the "legal netherworld" of who owns the fossils found on land, punctuated by court appearances, prison time, and a very pricey Sotheby's auction.


Even though the events played out years ago, the film is an honest-to-goodness nail-biter, even if you know how it turns out in the end. Watch it, watch it, watch it when it comes out in limited release and in VOD this Friday, August 15th.

In the meantime, I spoke with paleontologist Peter Larson—whose Love for Sue ran deeper and truer than anyone's, and continues on to this day—on the phone about what they used to unearth the T-Rex, how they ended up with so much video footage from the 90's-era dig, and the tech that will play a major role for future paleontologists.

Gizmodo: Finding Sue seemed like the perfect confluence of serendipity and skill. Susan Hendricksen said anyone with a knowledge of fossil versus rock would have seen the bones; can you tell me more about the visual difference between the two, and what you're looking for on a dig?

Larson: These dinosaur fossils were originally buried underground—several thousand feet in some instances, and certainly many hundreds of feet—in the the Hell Creek Formation, which is the layer of rocks in which you'll find Tyrannosaurus Rex. The weight of the rock that was above them caused the bones to fracture. As they came near the surface, they're freezing and thawing, and these changes in temperature also caused them to break up. The bigger pieces that made it down the hill were about fist size, with nothing much bigger than that.

If you look at those, they look different than the rock; they're still the same minerals that were created by the living organism—the same chemicals that your bones are made of (though there's lots more to it than that)—and you'll see the same bone structure where you see open spaces within the cells. If you collected fossils and stones from the Hell Creek Formation for a few days, you'd get the idea of what they look like. Your brain registers that. But that doesn't mean that anybody would have seen it. Maurice Williams had ridden past that hill hundreds of times but had never seen it, because he wouldn't necessarily have recognized it.


You found Sue in 1990. The documentary is filled with clips from news reports covering the ongoing saga, but one thing I found surprising was how much of the footage featured was from the dig itself. Was that common procedure at the time?


This was way before iPads and iPhones. We had a habit of doing a lot of 35mm still photography but most paleontologists at the time didn't record things with video. I saw the real value in recording in that manner after Susan bought her first video camera on a trip down to Peru; it was based on her initiative that we began doing it, and have been doing it ever since. There's certain things you can learn from a video that you can't with even still photographs. Now, of course, it's a lot easier to do.


That footage shows a huge range of equipment; what were the different elements essential to a paleontologist's toolbox at the time and how you used them?

When you start digging the overburden, you begin with the bigger tools. We used picks and shovels to get the mass of the encumbrance off; to get closer to the fossil we changed from bigger picks to smaller picks, then we switched to knives, and X-acto knives, and brushes. The bone itself has been shattered into hundreds and thousands of pieces, so one of the most important things once we're at the the bone itself is to conserve it, and glue it together, as we go.


As you're uncovering it?

Yep. For fractures we can see, we use cyanoacrylate; it's super glue, basically. Then we use polyvinyl acetate thinned with acetone; that's a general consolidant, which is basically Elmer's glue. We coat everything with that, so the whole thing's stuck together and we won't lose any pieces.


Once we get the fossil uncovered, we "pedestal" the bones either individually or in groups, depending on how tightly they're connected, then we add lumber to that mixture to help support the whole thing as well. Some of the casts we make using plaster of Paris and burlap are quite large; the one in the movie with Sue's skull, pelvis, and part of her body weighed about 10,000 pounds. We actually made a framework almost like a bridge trestle using triangles, which are some of the strongest shapes and very difficult to destroy, to sturdy it up as much as we could. We tunneled and put plaster and burlap underneath as well, then followed it with big beams which we used to hold the whole bottom together. That gets strapped into a metal frame and plastered together so it becomes one unit that's not going to move, because if it shifts it's going to crush the stuff inside.

Because it was seven or eight feet up on the face of the cliff, we threw debris around to create a slope so we could use gravity to get it down. Then we used pry bars to break away the last remnants of the pillars which were connecting it to the ground, and we were able to move it, very slowly and methodically using mechanical advantage—which is kind of the Egyptian method of moving things—onto these trailers. Instead of ropes we're using chains, cables, and come-alongs [portable winch and ratchets]. Because it's on a wooden pallet of these beams, we're able to we keep moving it onto sheets of plywood, which we'll move back and forth to get it down.


What kind of technological advances have been most helpful for paleontologists since finding Sue?

There's lots and lots of mapping techniques that we're able to use now, including LIDAR, which is basically laser-mapping of sites. It's the same thing they do in crime scene investigation. But GPS is really, really helpful, so you don't have to depend upon reading a topographic map and try to interpolate where your points are; we get a lot better accuracy and precision when we're at sites too. In addition the whole science of paleontology is changing tremendously; we can now map the chemistry of fossils, and map the elements across their surface.


So you're embracing the evolution?

Oh absolutely, absolutely. It's all so new, and it's a wonderful direction—way, way beyond what it was when Sue was discovered.


Dinosaur 13 will be out in limited release and VOD on Friday, August 15th, and it's incredible, so I'd highly recommend tracking it down!

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