Nautilus praepompilius

Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" after a period of apparent absence.

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.

A fossil is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the fossil record.

Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental landlocked country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbekistan to the south, and Turkmenistan to the southwest, with a coastline along the Caspian Sea. Its capital is Astana, known as Nur-Sultan from 2019 to 2022. Almaty, Kazakhstan's largest city, was the country's capital until 1997. Kazakhstan is the world's ninth-largest country by land area and the world's largest landlocked country. It has a population of 19 million people and one of the lowest population densities in the world, at fewer than 6 people per square kilometre. Ethnic Kazakhs constitute a majority of the population, while ethnic Russians form a significant minority. Kazakhstan is a Muslim-majority country, although ethnic Russians in the country form a sizeable Christian community.

Nautilus cookanum is an extinct species of nautilus. It lived during the Eocene epoch. N. cookanum placed within the genus Nautilus, together with extant species based on their shared shell characters. Fossils of the species from the Late Eocene Hoko River Formation are noted as one of the two oldest occurrences for the genus.

The Hoko River Formation is a Late Eocene marine sedimentary geologic formation. The formation is exposed in outcrops along the Strait of Juan de Fuca on the Olympic Peninsula in Washington state, USA. It is known for containing numerous fossils of crabs. It overlies the older Lyre Formation and underlies the younger Makah Formation.