THE living pandas are restricted to the mountains of south-eastern Asia where both the giant panda (Aeluropoda) and the lesser panda (Ailurus) occur. They overlap in geographical range only in Szechuan, China, and there they are separated altitudinally, with the lesser panda favouring higher elevations1. Pleistocene records extend the range of the giant panda into Burma and eastern China, but the lesser panda has apparently not had a significantly wider range during the Quaternary2. Considerable controversy surrounds the phylogenetic relationships of both genera as they represent some of the most derived of terrestrial Carnivora. Recent marshalling of anatomical evidence on the giant panda has demonstrated its fundamental affinity with other members of the Ursidae3. The position of the lesser panda is equivocal although it is usually assigned to the Procyonidae. Procyonids are widely thought to be restricted to the New World, but recent work on various Oligocene and early Miocene forms in Europe4 and North America5 indicate that the procyonids had a Holarctic distribution at that time. Regardless of its broader phylogenetic affinity, the presence of medial and late Miocene relatives of the lesser panda in Pakistan and western Europe (Sivanasua Pilgrim, 1931=Schlossericyon Crusafont, 1959)6 and their absence in the New World makes an Old World origin for this group highly likely. Thus the discovery of a single tooth in North America almost identical to European specimens of the extinct lesser panda Parailurus is unexpected, and must be explained by immigration from Asia.