Highest-Resolution Scan Ever Done of a Large Tyrannosaur Skull

Researchers at the Los Alamos National Laboratory in Albuquerque, New Mexico, used the laboratory’s unique neutron-imaging and high-energy X-ray capabilities to expose the inner structures of the fossil skull of a 74-million-year-old tyrannosauroid dinosaur nicknamed “Bisti Beast.” The image, the highest-resolution scan of a tyrannosaur skull ever done, provides information about how these predators evolved over millions of years.

Ron Nelson, of the laboratory’s Experimental Physical Sciences Division, said in a statement that this scan was atypical of the scans usually done in the laboratory. “Normally, we look at a variety of thick, dense objects at Los Alamos for defense programs, but the New Mexico Museum of Natural History and Science was interested in imaging a very large fossil to learn about what’s inside,” he said. Nelson was part of a team that included Los Alamos National Laboratory, the museum, the University of New Mexico, and the University of Edinburgh. “It turns out that high energy neutrons are an interesting and unique way to image something of this size,” he said.

The Los Alamos team combined neutron and X-ray computed tomography (CT) to extract new anatomical information from the 40-inch skull, which was found in 1996 in the Bisti/De-Na-Zin Wilderness Area near Farmington, New Mexico. The thickness of the skull required higher energy X-rays than those typically available to penetrate the fossil. The laboratory’s microtron electron accelerator produced the high-energy X-rays.

The team also used a newly developed, high-energy neutron imaging technique with neutrons produced by the proton accelerator at the Los Alamos Neutron Scattering Center to gain an alternate view inside the skull. The neutrons interact with nuclei rather than electrons, as X-rays do, and as a result have different elemental sensitivity. The information provided is complementary to that obtained with X-rays. Los Alamos has the unique capability to perform both methods on samples ranging from the very small to the very large scale.

The scan results allowed the team to determine the skull’s sinus and cranial structure. Initial viewing of the X-ray CT slices showed preservation of un-erupted teeth, the brain cavity, internal structure in some bones, sinus cavities, pathways of some nerves and blood vessels, and other anatomical structures.

These imaging techniques have revolutionized the study of paleontology over the past decade, allowing paleontologists to gain essential insights into the anatomy, development, and preservation of important specimens.