Oldest ‘Head-Butting’ Dinosaur Fossil Found in Mongolia; Team Includes Scientists From Okayama University of Science, Fukushima Museum

The Yomiuri Shimbun

10:47 JST, September 21, 2025

Fossil remains found in the Gobi Desert in Mongolia are those of a hitherto unknown species of the “head-butting” dinosaur featured in the film “Jurassic World,” and the oldest fossil of its type discovered so far, according to an announcement by a team of scientists.

A paper on the discovery was published in the science journal Nature on Thursday.

The scientists are from North Carolina State University, the Mongolian Academy of Sciences’ Institute of Paleontology and Geology, Okayama University of Science, Fukushima Museum and other institutes.

According to the research team, the fossil remains were discovered during an excavation in 2019 and were found to form an almost complete skeleton of a pachycephalosaurian dinosaur, which has a characteristically thick, dome-shaped skull. It is believed that dinosaurs of this type head-butted each other in fights over mates.

Before the excavation, the oldest known fossil of a pachycephalosaur was dated about 90 million years ago. The newly excavated fossil remains were older than that by 20 million years and found in a Lower Cretaceous stratum about 110 million years old.

The scientists confirmed that the fossil remains were from a hitherto unknown species, judging from the shape of its occipital region and the tendon of its tail as well as the size of the teeth in its lower jaw. They named the dinosaur Zavacephale rinpoche, which means “head origin precious one.”