The genus Allonautilus contains two species of nautiluses, which have a significantly different morphology from those placed in the sister taxon Nautilus. Allonautilus is now thought to be a descendant of Nautilus and the latter paraphyletic. Live individuals of the genus have only been collected in Papua New Guinea and the Solomon Islands. Little is known about their biology because they live in deep waters, whereas the more well-understood Nautilus genus lives closer to the surface. Species: \n* Allonautilus perforatus \n* Allonautilus scrobiculatus (type) – crusty nautilus