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National Geographic Emerging Explorer Ryan Carney Using X-Rays and Alligators to Bring Dinosaurs Back to Life

Ryan Carney with some of the tools he uses most: a modern skeleton, a high-powered microscope, and a very large computer screen. Photo courtesy Ryan Carney

This post is part of an ongoing series of interviews with the 2017 class of National Geographic Emerging Explorers.

Evolutionary biologist and epidemiologist Ryan Carney is one of 14 National Geographic Emerging Explorers for 2017. This group is being honored for the way its members explore new frontiers and find innovative ways to remedy some of the greatest challenges facing our planet. The 2017 class of Emerging Explorers will be honored at the National Geographic Explorers Festival in Washington, D.C. in June.

Combining artistic inspiration and scientific investigation, Ryan Carney is using everything he can to help better understand animals of the past and threats to human health in the present. He has received grants from the National Geographic Society for several years, and recently finished his long road of formal education with degrees in art, biology, business, and public health from Brown, Yale, and UC Berkeley. He also led a punk band on the Warped Tour for several summers.

You’ve studied and worked in so many fields. What is it that you most want to do?

I just want to focus on bringing dinosaurs back to life, so to speak.

And how exactly are you going to do that?

Let’s take the 3-D Archaeopteryx Project—we scanned the Thermopolis specimen of Archaeopteryx, which is the best preserved, most complete skeleton. And we used a novel type of radiography to look inside it. Once that raw data came out, engineers had to write algorithms to process that data and turn it into images. Once they’d handed it off to me I had to look at those images and use software to do pre-processing, fixing the contrast, etc. Then I handed that off to a colleague who did the segmentation, separating the bones from the rock, digitally.

This whole process took many years. There’s a lot of processing every step of the way to go from bones, to pixels, to voxels (3-D pixels), to get that transformation of the analog dinosaur to a digital dinosaur. Once that data is used to generate 3-D models, I bring it into modeling and animation software to create a skeleton. And then I rig it just like any other type of character in a Pixar movie and from there I animate it.

How do you know what’s the right way to make it move?

 

Well you can’t really say that a particular motion is the one “right way” that a fossil animal moved, but you can use insights from living animals as a way to constrain your reconstructions. I’ve come up with a process called “scientific motion transfer,” which as the name suggests, is a scientific version of this animation technique called motion transfer, where you can take joint rotations from one model and transfer them to another.

One of the things I did was analyze the locomotion of the closest living relatives to extinct dinosaurs: a walking alligator and a flying bird. From there I was able to assess their similarities and use this information to reconstruct a conservative flapping motion in Archaeopteryx.

Image courtesy Ryan Carney

Where did you get the alligator motion capture?

That was one of the chapters in my dissertation, and used XROMM—X-ray Reconstruction of Moving Morphology. That technology was designed at Brown University by Stephen Gatesy and Beth Brainerd. Essentially it’s two X-ray video systems that are pointed at your animal subject from two different views.

So in this case, I set up a treadmill (it’s called a JOG A DOG, for dogs to exercise indoors). I had four different alligators and I put them on the treadmill and used X-rays to essentially peer under the skin, under the flesh, to see how the bones moved, how the joint surfaces interacted. I was also measuring muscle activity at the shoulder, to then couple how the muscles were firing with how the bones were moving in three-dimensional space.

Then you CT scan the animal, creating 3-D models of each of the bones, and then within the modeling and animation program, you match the position of the bones to each frame of the video. So you’re able to use that X-ray video reference as a away to reconstruct the motion of, in this case, an alligator forelimb with very high precision and accuracy.

You sound so casual talking about this. How well behaved are alligators in a lab?

They all had very different personalities, and some would walk and some would not, and we started out with this one that was just this great walker. He just got up there and did the high walk instead of a belly-crawl motion. And he’d just start walking and not stop and we all thought “this is awesome, this is going to go so smoothly.”

The other ones just would not walk. Especially the second and third. They just would sit there. Even if we put some chicken in front of them, they just weren’t having it.

What if you just turned the treadmill on?

Oh, we did.

And they would just ride it off?

Yeah, they’d be like, “yeah, I don’t want to move right now.”

Ryan Carney, a tegu lizard, and the enclosed treadmill flanked by X-ray video cameras that record this and other animals’ inner anatomy in motion. Photo by Sabine Moritz

 

Did seeing the different personalities of the alligators give you any new insights?

It definitely provided a greater appreciation for intraspecific variability—what is actually going on with these behaviors, not just across species, but among different individuals of that species. It also emphasized the need to increase your sample size.

By analyzing as many animals as you can, you can look at general patterns and determine some of the underlying constants in their behavior.

It’s funny that you exist at this midpoint, where you reconstruct animals for which you only have the bones, and then you taking a living thing and trying to break down the information and get it back to the level of bones and parts you can study.

The key there is you really need to understand the extant, which is another word for the living, to understand the extinct.

So after all that 3-D scanning and modeling, is the final reconstruction only visible in a 2-D animation?

I’ll actually be bringing a HoloLens to the Explorers Festival in June. This HoloLens project is a collaboration with the Advanced Visualization Center at the University of South Florida, and this undergrad Spenser Mason who knows a software called Unity and was able to integrate my animation of Archaeopteryx where it comes up from the rock, reassembles, and starts flapping. He took that animation, brought it into Unity, and was able to create an interactive hologram as an app within HoloLens.

We’re bringing this holographic dinosaur into things like HoloLens, Oculus Rift, and Google Cardboard, so people around the world can download it, examine it, and learn from it—and even compare the Jurassic wishbone of Archaeopteryx with the wishbone of their Thanksgiving turkey.

You guys should make a Star-Wars-style holographic dinosaur chess set.

I should do that. Because I love chess and I would love to have a dinosaur chess set.

Photo courtesy Ryan Carney

What is your hope for the impact of people seeing this reconstruction?

I hope they’ll love the specimen and the species. Archaeopteryx was found over 150 years ago and it was really the poster child for evolution ever since it was found, because it shows this intermediate form between birds and reptiles: it has this long bony tail, claws on its fingers, and teeth in its mouth, but it has this fully modern avian plumage.

It was also found just two years after Darwin’s On the Origin of Species was published and it really exemplified what he was talking about in terms of these transitional forms. In fact, Darwin even wrote in future editions about this “strange bird with a long lizard-like tail.” And even though we now have all these amazing feathered dinosaurs, winged dinosaurs, even bat-winged dinosaurs, from places like China, these are from locations where the specimens are very crushed just due to geological processes. So you can’t really do this three-dimensional reconstruction and analysis that you need in order to answer these functional questions.

So that brings me to the next thing which is that Archaeopteryx has been called the first bird, and the first dinosaur that we know of that was capable of powered flight, but even that has been controversial, and has been one of the great unanswered questions in paleontology: How did flight arise, and was Archaeopteryx capabale of powered flight? Previous work that modeled Archaeopteryx’s flight simplified its anatomy down to body mass, and wing span, etc. But really the only way to address that is through three-dimensional reconstruction and analysis.

This locomotor innovation of flight is what allowed birds to become the most successful group of land animals ever. It’s really the age of birds that we’re living in. So I want us to know how dinosaur flight evolved and the best way to answer that is to look at the best skeleton using the best technology available. That’s really what I was reaching for with this project.

What inspires you to keep working on this project?

I think now more than ever it’s important to have those sorts of resources, with educational funding being cut and scientific literacy so low. A project like this is a great way to get kids excited and engaged. I mean, it’s virtual reality and flying dinosaurs that they can see through their phones! It’s a great match that way and a great way to teach anatomy and evolution to kids around the globe who otherwise wouldn’t be exposed to those sort of things.

And then you also help track and predict outbreaks of diseases like Dengue Fever and Zika. Is there a way these two topics intersect?

My epidemiology work has really been heavy in GIS (geographic information systems), but that’s been pretty underutilized in paleontology. For example, if we know where fossils are, we can overlay things such as satellite data and digital elevation maps, and come up with a predictive map of where the fossils may be, just like we do when we’re predicting disease outbreaks using GIS. That way you wouldn’t have to rely on the old-school prospecting methods where you’re walking through the field and you trip over a fossil and that’s your excavation site.

[Updated 6/12/2017]

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