Anelosimus terraincognita is a species of spider discovered in the Rijksmuseum van Natuurlijke Historie, with no associated information as to its collector or location of discovery. Males have a corkscrew-shaped embolus, which is a characteristic unique to Australasian species within the Anelosimus genus. It is known only from the holotype specimen, which has a total length of 2.2 millimetres (0.087 in). It is named for the cartographic Latin phrase terra incognita, meaning unknown land.