''Pseudorthocerataceae'' is an extinct

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of actively mobile

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

, essentially a '' Nautiloid'', that lived in what would be

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Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

during the Ordovician from 490—445.6

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, existing for approximately .

Taxonomy

''Pseudorthocerataceae'' was named by Sweet (1964). It was assigned to ''

Pseudorthocerida Pseudorthocerida is an order of generally straight longiconic orthoceratoids with a subcentral to marginal cyrtochoanitic siphuncle composed of variably expanded segments which may contain internal deposits that may develop into a continuous p ...

'' by Barskov (1968); and to ''

Orthocerida Orthocerida is an order of extinct Orthoceratoid cephalopods also known as the Michelinocerida that lived from the Early Ordovician () possibly to the Late Triassic (). A fossil found in the Caucasus suggests they may even have survived until ...

'' by Sweet (1964), Evans (1994) and Evans (1994).D. H. Evans. 1994. The Cephalopod Fauna of the Bardahessaigh Formation (Caradoc Series) of Pomeroy, County Tyrone. Irish Journal of Earth Sciences 13:11-29

Morphology

The shell is usually long, and may be straight ("

orthoconic An orthocone is an unusually long straight shell of a nautiloid cephalopod.; During the 18th and 19th centuries, all shells of this type were named ''Orthoceras'', creating a wastebasket taxon, but it is now known that many groups of nautiloids d ...

") or gently curved. In life, these animals may have been similar to the modern

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

, except for the long shell.

Fossil distribution

Fossil distribution is exclusive to

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Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

USA, and northern

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References

{{Taxonbar, from=Q7255508 Prehistoric nautiloids Ordovician cephalopods Late Ordovician extinctions Paleozoic cephalopods of Asia Paleozoic cephalopods of Europe Paleozoic cephalopods of North America Paleozoic animals of Oceania