''Chazyoceras'' ("Horn of the Chazyan") is a moderately large

endocerid Endocerida is an extinct nautiloid order, a group of cephalopods from the Lower Paleozoic with cone-like deposits in their siphuncle. Endocerida was a diverse group of cephalopods that lived from the Early Ordovician possibly to the Late Silurian ...

included in the

Endoceratidae Endoceratidae is a family of large to very large straight shelled nautiloid cephalopods belonging to the order Endocerida that lived during the Middle and Late Ordovician. They include the largest known Paleozoic invertebrates, represented by ''E ...

with a ''

Nanno Nanno (german: Nain, Ladin: ''Nan'') was a '' comune'' (municipality) in Trentino in the northern Italian region Trentino-Alto Adige/Südtirol, located about north of Trento. As of 31 December 2004, it had a population of 623 and an area of ...

'' type apex and a ventral

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 ...

with a holochoanitic (where "holo" is entire, and "choan" refers to its funnel-shaped opening) wall, characteristic of the family. The

swelling at the apex is subtriangular in longitudinal profile. The endocones are of medium length. ''Chazyoceras'' was named 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 st ...

in 1958. 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 ''Chazyoceras valcourense'' which came from the Middle Chazyan (Lower Middle

Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. ...

) of Valcour Island on

Lake Champlain , native_name_lang = , image = Champlainmap.svg , caption = Lake Champlain-River Richelieu watershed , image_bathymetry = , caption_bathymetry = , location = New York/Vermont in the United States; and Quebec in Canada , coords = , type = , ...

. ''Chazyoceras'' resembles '' Perkinsoceras'' which Flower included in the Allotrioceratidae - a family which Flower named and included in the Endocerida based on the strange fossil, '' Allotrioceras'' Both ''Chazyoceras'' and ''Perkinsoceras'' types are housed in the paleontology collection at th
New Mexico Museum and Natural History and Science
in Albuquerque, where they were transferred from Flower's collection at the New Mexico Bureau of Mines in Socorro.

References

* Flower, R. H 1958. Some Chazyan and Mohawkian Endoceratida, Jour Paleon V 32, N.2, pp 433–458, May 1858. * Flower, R.H 1976 Some Whiterock and Chazy Endooceroids, Memoir 28, Part II, New Mexico Bureau of Mines and Mineral Resources, Socorro, New Mexico * Teichert, Curt 1964. Endoceratoidea; Treatise on Invertebrate Paleontology, Part K Mollusca 3; Geol Soc of America and University of Kansas Press {{Taxonbar, from=Q5088692 Prehistoric nautiloid genera Taxa named by Rousseau H. Flower