For North Dakota Paleontologist, It Started With a Turtle MARMARTH, N.D. - It is not uncommon for young girls and boys to ask their parents for a pet turtle. But how many children collect dead ones? That was the passion Tyler Lyson developed while growing up in this hamlet of 140 people on the edge of the badlands of southwestern North Dakota - not out of some morbid fascination, but as a happy consequence of an inborn entrepreneurial spirit and of being raised near one of the richest fossil beds in North America. Once a bustling railroad town, Marmarth is situated amid the buttes of the Hell Creek geological formation, which spans parts of North Dakota, South Dakota, Montana and Wyoming. With their gray, orange and black bands, the buttes have long been of interest to paleontologists: Their sediments were deposited 65 million to 67 million years ago, just before and after the dinosaurs became extinct, and they are a rich trove of fossils - including all of the best-known specimens of Tyrannosaurus rex. That nearby attraction presented a splendid business opportunity for an enterprising young man. When professional collectors came to the area - "bone diggers," as Tyler Lyson, now 29, still calls them - they needed an escort who knew his way around the area's vast private ranches. Tyler took on his first client (a professor from Alabama) when he was still in the fifth grade. The pay was very good, and the work beat his regular job of mowing the grass at the town cemetery. It also gave him a chance to learn some fossil-collecting basics, and within a year he was able to put that knowledge to use. He was out riding on his A.T.V. by himself one cold fall day among the buttes when he spotted a turtle's fossilized shell. He was used to seeing bone shards and shell fragments on the surface of the eroding slopes, but never a complete shell. When he looked more closely, he also found a skull and a limb bone, suggesting that there might be more of the animal to uncover. The next weekend he dug an excavation pit, just as he had learned from the bone diggers. He hit the jackpot - 10 or 12 more shells of the same species, all piled together. The turtles had most likely died together as a pond dried up in a drought, creating what he dubbed the Turtle Graveyard. A quarter-mile away he found another bonanza, 50 shells, atop what he named Turtle Ridge. Then he found his first dinosaur. It was just a hadrosaur, or duck-billed dinosaur, a fairly common species for the region, but it was extraordinary in that it still held fossilized impressions of the skin. It took all of Tyler's middle school years, as well as some professional help, to extract the rare find. "I think I peaked in sixth grade," he jokes today. Tyler dreamed of becoming a professional paleontologist. But the world of academia and science museums was a long way from Marmarth. So was high school. After graduating from the eighth grade (in a class of three), he traveled 36 miles round trip every day to Baker, Mont., to earn his diploma, and kept on digging in his spare time. His father, Ranse Lyson, gave him a bench in his wood shop for his specimens, but the fossils soon took over the entire space. While his dinosaurs sometimes earned headlines - he found another skin-bearing hadrosaur, nicknamed Dakota, while still in high school - turtles remained his passion. He chose Swarthmore College in large part because Scott F. Gilbert, a biology professor there, promised to let him study one of the great turtle mysteries: how the animal makes its shell. Unlike humans and other vertebrates, which have flexible rib cages, turtles uniquely have an immovable rib cage - fused to, and part of, the shell. Their limbs form from within the rib cage. How they pulled off these innovations remains an evolutionary puzzle. After four years at Swarthmore, Mr. Lyson moved on to graduate school at Yale. Working with the paleontologist Jacques Gauthier, he addressed another longstanding mystery - about turtles, of course. We know from the fossil record that turtles evolved at least 220 million years ago, in the Triassic period, but their ancestry has been uncertain, along with their relationship to other reptile forms. Efforts to settle the question have focused on anatomical comparisons between fossils and living animals. Mr. Lyson decided to go beyond fossils and look at turtles" genes. In a 2011 paper in Biology Letters, he, Dr. Gauthier, Kevin J. Peterson of Dartmouth and colleagues found that certain turtle genes were shared only with lizards - and not with crocodiles or birds, which are descended from dinosaurs. The discovery indicates that of all reptiles, turtles are most closely related to lizards, despite their radically different bodies. This past May, Tyler Lyson became Dr. Lyson. But while earning his credentials out East, he never left Marmarth behind. While at Swarthmore, he formed the nonprofit Marmarth Research Foundation to support paleontological research and public education in the area. With the support of local donors and the help of volunteers, the foundation recently built a field laboratory in Marmarth. I met Dr. Lyson in his new, well-furnished hometown lab, where he proudly displays a menagerie of turtles collected over almost two decades. And the turtles from these badlands tell one very important story. Most of the two dozen or so species Dr. Lyson has found in lower, late Cretaceous sediments are also found in the early Paleocene sediments lying above them. This means that turtles survived the catastrophic asteroid impact that doomed their neighbors the dinosaurs. Large land-dwelling dinosaurs required vast quantities of fresh plants or prey, but the much smaller turtles managed to get by while many plants and other animals went extinct. That is one more reason to better understand and appreciate turtles, even though dinosaurs hog the spotlight. Now Tyler Lyson is off to the Smithsonian's National Museum of Natural History for the next stage of his career, where he will work - no surprise - on the evolution of turtles. As he happily acknowledges, "It has been a dream come true, so far."