After two years of research, the J. Paul Getty Museum has decided to voluntarily return a terracotta head believed to depict the god Hades to Sicily, where recent excavations have uncovered fragments indicating that the head was illicitly removed in the 1970s from a site of a sanctuary of Demeter.

“In keeping with the principle of repatriating works when compelling evidence warrants it, the decision to transfer this head is based on the discovery of four terracotta fragments found near Morgantina in Sicily, similar in style and medium to the Getty head,” the museum said Thursday in a statement....