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

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

found in eastern North America (

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

and

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the 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 study ...

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 biological tissue, tissue passing longitudinally through the mollusc shell, shell of a cephalopod mollusc. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the li ...

. The conical shell is suggestive of

belemnite Belemnitida (or belemnites) is an extinct order (biology), order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous (And possibly the Eocene). Unlike squid, belemnites had an internal skeleton that made up the cone ...

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

References

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