The western lowland olingo (Bassaricyon medius) is a species of olingo from Central and South America, where it is known from Panama and from Colombia and Ecuador west of the Andes.[1]
The western lowland olingo is smaller than the northern olingo, but larger than the most montane member of the genus, the recently described olinguito ("little olingo").[1] While the Panamanian subspecies B. m. orinomus is about the same size as the eastern lowland olingo, the subspecies from west of the Andes, B. m. medius is smaller.[1] The pelage is slightly lighter than that of the eastern species.[1]
It has a head-body length of 31to, with a tail length of 35to.[1] It weighs 0.9to.[1]
There are two subspecies of the western lowland olingo: the nominate B. m. medius (Colombia and Ecuador) and B. m. orinomus (Panama and possibly Colombia).[1] The closest relative of the western lowland olingo is the other lowland olingo species, B. alleni, found east of the Andes, from which it diverged about 1.3 million years ago.[1]