New pachycephalosaur, a dome-headed dinosaur, from Mongolia (earthsky.org) [View all]

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Posted by Shireen Gonzaga
September 24, 2025

A new pachycephalosaur fossil from the Gobi Desert

Pachycephalosaurs are dinosaurs known for the prominent helmet-like bony dome at the top of their heads. They likely used it in headbutting displays, much like modern-day bighorn sheep. On September 17, 2025, scientists said they’ve discovered a new species of pachycephalosaur from the Gobi Desert in Mongolia, dating to about 108 million years ago. They named it Zavacephale rinpoche. The discovery is significant because it is the oldest and most complete pachycephalosaur fossil paleontologists have yet found. Plus, this specimen was a juvenile that had already developed its iconic dome at the top of its skull.

Lindsay Zanno, at the North Carolina Museum of Natural Sciences, is one of the paper’s co-authors. She said:

This specimen is a once-in-a-lifetime discovery. It is remarkable for being the oldest definitive pachycephalosaur, pushing back the fossil record of this group by at least 15 million years, but also because of how complete and well-preserved it is. Z. rinpoche gives us an unprecedented glimpse into the anatomy and biology of pachycephalosaurs, including what their hands looked like and that they used stomach stones to grind food.

The researchers published their findings in the peer-reviewed journal Nature on September 17, 2025.
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The researchers named the new dinosaur species Zavacephale rinpoche. Zava, they said, means root or origin in Tibetan while cephal is head in Latin. The species name rinpoche translates to precious one in Tibetan.

This new find is remarkable because the scientists recovered about half of the animal’s skeleton, the most ever found for a pachycephalosaur. They excavated a well-preserved skull, along with some limb and tail bones. And, for the first time, they discovered pachycephalosaur hand bones. They also found gastroliths, or stomach stones, the first ever associated with pachycephalosaurs. These were stones the dinosaur swallowed to help grind food in its digestive system.
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more: https://earthsky.org/earth/new-pachycephalosaur-zavacephale-rinpoche-dome-headed-dinosaur-mongolia/?mc_cid=3d5f411a72