Engorthoceratidae is a small family of Devonian orthocerids and a class of

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 ...

found in eastern North America (

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and

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

), containing only the genus ''Engorthoceras''.R. H. Flower. (1962). "Notes on the Michelinoceratida". State Bureau of Mines and Mineral Resources, New Mexico Institute of Mining and Technology, Memoir 10, Part II Engorthoceratidae
PaleoBiology Database

Taxonomy

Engorthoceratidae was named in 1962 by

Rousseau Flower Rousseau Hayner Flower (1913–1988) was an extremely prolific 20th century paleontologist, known for his eccentric personality. Career Although trained as an entomologist, and a specialist in dragonflies and orthopterans, Flower began stud ...

to contain the genus ''Engorthoceras'', also named by Flower (1962), and assigned to the Michelinceratida. The

genotype The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a ...

is ''Orthoceras worthoni''.

Morphology

''Engorthoceras'' produced straight conical shells with a subcircular cross section and a small completely marginal

siphuncle The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and ...

. The conical shell is suggestive of

belemnite Belemnitida (or the belemnite) is an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous. Unlike squid, belemnites had an internal skeleton that made up the cone. The parts are, from the arms-most to ...

phragmocones and of its possible ancestry to '' Eobelemites''. Nothing is known of the animal itself.

References

Devonian cephalopods Prehistoric nautiloid families Monogeneric mollusc families Devonian first appearances Devonian extinctions Taxa named by Rousseau H. Flower Orthocerida {{paleo-Nautiloidea-stub