东戈壁省
All known specimens of "Altirhinus" were recovered in 1981 during collaborative expeditions organized by Soviet and Mongolian scientists, from the Khukhtek Formation in the Dornogovi Province of Mongolia. The Khukhtek was formed in the Aptian to Albian stages of the Early Cretaceous Period, which lasted from between 125 and 100.5 million years ago. "Psittacosaurus" and the primitive ankylosaurid "Shamosaurus" have also been found in these rocks.