The skeleton will tell researchers much more about the anatomy of pachycephalosaurs, two-legged herbivores that are among the ...

A specimen discovered in Mongolia is the most complete fossil yet found of a pachycephalosaur, a dinosaur believed to be built for head-butting.

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 ...