In a new study published in the journal Science, scientists detail the identification of a new species of gibbon, one that had gone extinct at some point over the past two millennia. The remains of Junzi imperialis were first discovered in 2004, when archaeologists at Shaanxi Provincial Institute of Archaeology in Xi’an discovered a mausoleum nearby the tomb of Qin Shi Huang, China‘s first emperor, which is famously guarded by thousands of terracotta soldiers. In addition to the partial skull of the gibbon, the mausoleum contained bones from numerous animals, such as panthers, lynxes, black bears and cranes. The gibbon likely would have belonged to the emperor’s grandmother, Lady Xia. “Having gibbons as pets appears to have been common among Chinese royals during ancient times,” study co-author Alejandra Ortiz told NPR.