Balticoceras
Encyclopedia
Balticoceras is a genus in the Orthocerid family, Orthoceratidae
, from the Upper Ordovician of Estonia, closely related to Michelinoceras
. Balticoceras is distinguished by its straight shells with a subcircular cross section, broadly flattened ventrally and evenly rounded dorsally, and by its marginal, orthochoanitic siphuncle. Balticoceras which is included in the subfamily Michelinoceratinae along with Michelinoceras should not be confused with Baltoceras
which belongs in the Ellesmerocerida
.
Orthoceratidae
Orthoceratidae, is an extinct family of actively mobile carnivorous cephalapods, subclass Nautiloidea, that lived in what would be North America, Europe, Asia, Africa, and Australia from the Ordovician through Triassic from 490—203.7 mya, existing for approximately .-Taxonomy:Orthoceratidae was...
, from the Upper Ordovician of Estonia, closely related to Michelinoceras
Michelinoceras
Michelinoceras is the oldest known genus of the Michelinocerida, more commonly known as the Orthocerida, characterized by long, slender, nearly cylindrical orthocones with a circular cross section, long camerae, very long body chambers, and a central or near central tubular siphuncle free of...
. Balticoceras is distinguished by its straight shells with a subcircular cross section, broadly flattened ventrally and evenly rounded dorsally, and by its marginal, orthochoanitic siphuncle. Balticoceras which is included in the subfamily Michelinoceratinae along with Michelinoceras should not be confused with Baltoceras
Baltoceras
Baltoceras is a member of the Ellesmerocerida, included in the family, Baltoceratidae. The shell of Baltoceras is slender with a subcircular cross section, straight transverse sutures, and a large siphuncle in contact with the venter...
which belongs in the Ellesmerocerida
Ellesmerocerida
The Ellesmerocerida is a order of primitive cephalopods belonging to the subclass Nautiloidea with a widespread distribution that lived during the Late Cambrian and Ordovician.-Morphology:...
.
References
- Walter C. Sweet 1964. Nautiloidea- Orthocerida. Treatise on Invertebrate PaleontologyTreatise on Invertebrate PaleontologyThe Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and...
, Part K. Teichert and Moore (eds)