Paractinoceras

Paractinoceras
Temporal range: Middle Ordovician
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Actinocerida
Family: Actinoceratidae
Genus: Paractinoceras
Hyatt in Zittle, 1900

Paractinoceras is a long straight slender actinocerid ammonite with siphuncular segments in the early stages like those of Actinoceras, becoming narrower in the later stages of the chambered phragmocone like those in Ormoceras. As with Kochoceras and Floweroceras Paractinoceras is considered a separate genus within the Actinoceratidae, distinct from Actinoceras.

References


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