A fourth as yet unconfirmed species, the giant peccary ("Pecari maximus"), was described from the Brazilian Amazon and north Bolivia by Dutch biologist Marc van Roosmalen. Though relatively recently discovered, it has been known to the local Tupi people as "caitetu munde", which means "great peccary which lives in pairs". Thought to be the largest extant peccary, it can grow to in length. Its pelage is completely dark gray, with no collars whatsoever. Unlike other peccaries, it lives in pairs, or with one or two offspring. However, the scientific evidence for considering it as a species separate from the collared peccary has later been questioned, leading the IUCN to treat it as a synonym.