A 21-inch dome-shaped skull arrived at the Smithsonian this year with something paleontologists almost never get: an intact face.
The fossil belongs to a Pachycephalosaurus—a bipedal herbivore that roamed what is now South Dakota about 67 million years ago. It was excavated in 2024 from the Hell Creek Formation, a site known for Upper Cretaceous fossils, and donated to the National Museum of Natural History by philanthropists Eric and Wendy Schmidt, who purchased it at Sotheby's for $1.7 million.
What makes this skull remarkable isn't just its completeness. It's how rare that completeness is. Pachycephalosaurus remains make up less than 1% of all fossils found in the Hell Creek Formation. Most discoveries are scattered bone fragments. Heads especially tend to separate and scatter during fossilization—which means most dinosaur skulls paleontologists study are reconstructions, pieced together from multiple animals or missing crucial details.
We're a new kind of news feed.
Regular news is designed to drain you. We're a non-profit built to restore you. Every story we publish is scored for impact, progress, and hope.
Start Your News DetoxThis one has 32 fused cranial bones and many of its original teeth still in place. Matthew Carrano, the Smithsonian's Dinosauria curator, called it "by far the most spectacular specimen of this type of dinosaur that we have at the museum." For researchers, that means new chances to understand how these animals actually lived—how they chewed, how their senses worked, what their faces told us about their behavior.
What happens next
The skull is on public view through December 28 in the museum's FossiLab, a glass-walled workspace where visitors can watch preparators carefully extract remaining rock and sediment from the fossil. It's part of the permanent "Deep Time" exhibition in the David H. Koch Hall of Fossils, which opened in 2019 and spans 31,000 square feet.
After this viewing window, the Pachycephalosaurus will take its place in the permanent collection—a reminder that some of the most important scientific discoveries aren't always the most recent ones. Sometimes they're just the most complete.
