Allonautilus

The nautilus is a pelagic marine mollusc of the cephalopod family Nautilidae. The nautilus is the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina.

Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features.

In biology, a taxon is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping.

Nautilus is a genus of cephalopods in the family Nautilidae. Species in this genus differ significantly in terms of morphology from those placed in the sister taxon Allonautilus. The oldest fossils of the genus are known from the Late Eocene Hoko River Formation, in Washington State and from Late-Eocene to Early Oligocene sediments in Kazakhstan. The oldest fossils of the modern species Nautilus pompilius are from Early Pleistocene sediments off the coast of Luzon in the Philippines.

In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic with respect to the excluded subgroups. In contrast, a monophyletic group includes a common ancestor and all of its descendants. The terms are commonly used in phylogenetics and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic.

Papua New Guinea, officially the Independent State of Papua New Guinea, is a country in Oceania that comprises the eastern half of the island of New Guinea and its offshore islands in Melanesia. Its capital, located along its southeastern coast, is Port Moresby. The country is the world's third largest island country, with an area of 462,840 km2 (178,700 sq mi).

Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and northwest of Vanuatu. It has a land area of 28,400 square kilometres (11,000 sq mi), and a population of approximately 700,000. Its capital, Honiara, is located on the largest island, Guadalcanal. The country takes its name from the wider area of the Solomon Islands (archipelago), which is a collection of Melanesian islands that also includes the Autonomous Region of Bougainville, but excludes the Santa Cruz Islands.