Zavacephale rinpoche at time of discovery. Credit: Tsogtbaatar Chinzorig (CC BY-NC-ND)Palaeontologists have unearthed a new species of dinosaur in a “once-in-a-lifetime discovery” which pushes back the earliest record of dome-headed pachycephalosaurs by 15 million years. The species, Zavacephale rinpoche, lived 108 million years ago (mya) during the Early Cretaceous period in what is today Mongolia’s Gobi Desert. Zavacephale rinpoche skull. Zavacephale rinpoche hand bones.