Photo: Joshua Dalsimer

OLD BONES: Nels Peterson brings an engineer’s outlook to paleontology.

Nels Peterson was just 8 when he found his first skull. “It was summertime, and my friend and I were digging an underground fort,” he recalls. In the process, they unearthed the intact skeleton of…something.

“The skull was really strange—it was about the size of a horse’s head, but it wasn’t a horse, because it had four tusks coming out the front,” says Peterson. “I took it to school in a bread sack for show-and-tell.”

The mystery was solved when somebody in town recalled that the site of their dig—Peterson’s backyard—used to be a cheese factory. The factory owner had kept some pigs, one of which was interred on the factory grounds. “It wasn’t exactly a dinosaur,” Peterson says. “But it was very exciting to us.” Dinosaur bones would come later.

Peterson grew up in the tiny western Montana town of Corvallis, population 443, where his parents still run an auto repair shop. He wasn’t a particularly motivated student. “I was always in trouble,” he recalls. “They almost kicked me out of high school.” Then a perceptive teacher put him in touch with a local computer expert, who taught him how to program and, Peterson says, “gave me something to do, other than make a mess of things.”

After enrolling as an electrical engineering student at Montana State University, in Bozeman, he started working part-time at the university’s Museum of the Rockies, home to one of the largest collections of Tyrannosaurus rex remains in the world. Once again he found himself digging in the dirt. During summer breaks, he and a small crew of researchers and volunteers would head out to the field for anywhere from a couple of weeks to a few months, living in tents or trailers, far away from electricity, running water, and most other modern amenities. “Within a week, you know everything about everyone, whether you want to or not,” he says.

“One of the first things people ask when they come out to the field is, ‘What does a bone look like?’ ” Peterson says. “But that is one of the most complicated questions to answer.” It depends on things like the type of bone, how it was preserved, and whether it’s broken or intact. The bones also absorb minerals from the surrounding soil until it’s hard to distinguish one from the other—and easy to mistake a bone for a fossilized tree branch and unwittingly destroy it. “Those are the bad days,” Peterson says.

But the discoveries can be enormous. On one dig, he and his crew unearthed a T. rex skull that was so well preserved it actually contained some soft tissue. During another excavation in Niger, led by Paul Sereno of the University of Chicago, the crew unearthed the remains of a “supercroc,” a humongous, 12-meter-long ancestor of the modern crocodile that lived 110 million years ago in the region that’s now the Sahara.

Becoming a professional dinosaur hunter “wasn’t something I planned on doing,” Peterson says. “But pretty soon I was spending all my time on it.” After Peterson graduated, two years ago, the museum’s chief paleontologist, Jack Horner, offered him a full-time job, but he declined. “I love hanging out with geologists and biologists, but I knew I needed to be around other engineers at least part of the time.” So now he has two homes: during the spring and summer he lives in Montana, or wherever the ­museum’s excavations take him, and he winters near Boston, where his wife, Laura Loge, is training to be an opera singer at the New England Conservatory of Music.

It’s a life seemingly designed to explore extremes. Peterson spent last summer overseeing a dig in a remote region of Mongolia. Being the sole engineer on a crew means that he is also the technical support person. Anything that breaks, he fixes, whether it’s a car engine or the base camp’s satellite link. The crew’s immediate goal was to unearth a fossilized flock of ­psittacosaurs, flightless birds that slightly resemble today’s parrots. Peterson and his Montana colleagues also trained local scientists who wanted to set up a paleontology research team of their own.

Lately, Peterson can be found at the Center for Bits and Atoms at MIT. It’s a techie’s dream, because he has access to the center’s vast workshop of high-end machining and modeling equipment and gets to bounce ideas off some of the smartest engineers around.

Peterson is exploring a technique that he thinks could revolutionize paleontology. On a typical dig, he explains, you choose a geologically promising site to excavate, and then you painstakingly remove layers of dirt by hand until the entire site is exposed. Diggers take photos and notes and sketch plots of what they find. Then they wrap up the bones and ship them back to the lab for further study.

But Peterson finds the end result unsatisfying. “You wind up with drawers and boxes of old bones, but nothing else,” he says. “You don’t know what the ground around the dinosaur looked like or exactly how the body was positioned. You lose 99 percent of the information getting that 1 percent.”

A more revealing technique would be to create a three-dimensional map of a site. That would entail scraping off thin layers—dirt, bones, and all—and imaging each layer using a lidar scanner equipped with a camera, then using computer modeling software to re-create a 3-D picture of the whole. You’d still have the bones at the end, but Peterson thinks the resulting image—which could be rotated, peeled back, and viewed from different angles—would be at least as valuable. He hopes to try out his lidar system in the field next summer.

As an engineer among paleontologists, Peterson says, “the most crucial thing I can offer is a different way of thinking, a different way of looking at things.”