Figure 1. Some characteristic craniometric differences between young adult and older Arctonyx, as demonstrated by two female skulls of A. hoevenii from northern Sumatra. Above, USNM 269073, adult female from 'Atjeh'; below, ANSP 20232, young adult female from Gunung Leuser. Young adults generally match adults/old adults in overall length, but have the zygomata weakly expanded in comparison, the interorbital and postorbital regions less constricted, cranial cresting less pronounced, and the surfaces of the teeth less worn.