In 1985, David Gillette, a paleontologist at the New Mexico Museum of Natural History & Science, gave a lecture at Los Alamos National Laboratory. Hikers had recently stumbled across eight large dinosaur vertebrae embedded in sandstone in the Ojito Wilderness Study Area, just northwest of Albuquerque. Gillette wanted to know more about the creature that was presumably contained in the rock. He posed a question to his audience of scientists: Is there a way to “see” into the ground to know where to dig for bones?
“Los Alamos scientists took up the challenge,” Gillette wrote in his 1994 book Seismosaurus: The Earth Shaker. And not only did Los Alamos scientists volunteer their time and equipment, but they also invited colleagues from Sandia and Oak Ridge national laboratories to do the same.
Before long, Gillette wrote, the excavation became “a multifaceted experiment involving not just traditional paleontology, but also chemistry, physics, engineering, electronics, and a little bit of magic—magical science and magical friendships.”
Over the course of about six years, scientists conducted a range of experiments to detect and date the bones of “Sam,” the first known Seismosaurus and thought to be the longest known dinosaur at the time of its discovery. “The joke around here is that Seismosaurus has become the largest project at Los Alamos,” electron microscopist Roland Hagan told The Scientist magazine in 1991. (Seismosaurus was later recategorized as a species of Diplodocus, Diplodocus hallorum.)
One of the first experiments involved holding one of Sam’s bones under ultraviolet light in a men’s bathroom at the Laboratory. Why the men’s bathroom? “It can be made absolutely dark,” Gillette wrote. “So, several of us crowded in, turned on the ultraviolet lamp, and turned off the lights.” The result? “The fossil bone glowed,” Gillette wrote. “The glow comes not from uranium minerals in the fossil bone but from the natural fluorescence of the hydroxyapatite, a crystalline mineral found in all living bone and probably all fossil bone in its original state.” The follow-up experiment involved black lights at the excavation site on a moonless night.
Many experiments had to do with locating bones deep within the sandstone using technologies such as gamma ray detectors, sonar, ground penetrating radar, and magnetometry. Some of these technologies had been successfully deployed in other fields, for example, to search for buried pyramids and detect fault lines, but as Gillette explained, “Dinosaur bones, even the largest bones of a skeleton, were two or three orders of magnitude smaller than the underground targets archaeologists and geologists had their sights on.” The use of these tools for paleontology was unprecedented and, in the end, semi-successful. Scientists were able to identify potential targets, many of which were later verified during excavation.
Some targets, however, were duds. Physicist and engineer Bob Webster, a new Laboratory employee at the time (and now deputy director for Weapons), was involved in the excavation and recalls that an anomaly—a different density in the sand—was detected in an area below the surface. Hoping he might unearth a piece of Sam, Webster spent an entire summer on repeat: jackhammering a few inches of rock, carefully sweeping it away, and then carefully looking for bone. Alas, he says, “we got down to the target depth, and it was just wet sand.”
In the 30-plus years since the Seismosaurus project, Los Alamos has occasionally lent its expertise to other paleontology projects. For example, in 2017, the Laboratory’s unique neutron-imaging and high-energy x-ray capabilities exposed the inner structures of the 40-inch-long fossil skull of the Bisti Beast, a 74-million-year-old tyrannosauroid dinosaur discovered near Farmington, New Mexico, in 1996. The high-resolution images allowed scientists to determine the skull’s sinus and cranial structure, including the presence of unerupted teeth and the pathways of some nerves and blood vessels.
Involvement in these types of projects is “a classic example of why a national lab exists,” Hagan told The Scientist. “There’s no commercial value in excavating dinosaur bones, so no private company is going to fund the work. And a university isn’t likely to have all the different equipment that you’d need to do the job right. But here at Los Alamos, we cut across all disciplinary boundaries. And we have resources that aren’t available anywhere in the world.” ★
Roland Hagan passed away on June 15, 2024.
A mammoth discovery
Los Alamos isn’t the only nuclear weapons laboratory to dabble in paleontology. In 1997, the remains of a prehistoric mammoth were unearthed during the construction of the National Ignition Facility at Lawrence Livermore National Laboratory in California.
Jeff Paisner, currently a project-program manager at Los Alamos, was overseeing construction when a skull and jawbone were unearthed, followed soon thereafter by additional bones and a tusk. Livermore’s accelerator mass spectrometer was used to help date the remains, which are currently estimated to be about 10,000 years old. “It’s somewhat surrealistic to see this modern-day construction taking place on one side of the site and, in this corner, paleontologists working on bones that are several hundred thousand years old,” Paisner told KCBS News Radio shortly after the discovery. ★