''Amyzon'' is an extinct genus belonging to the sucker

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Catostomidae The Catostomidae are the suckers of the order (biology), order Cypriniformes, with about 78 species in this family (biology), family of freshwater fishes. The Catostomidae are almost exclusively native to North America. The only exceptions are ' ...

first described in 1872 by

E. D. Cope Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, he distinguished himself as a child prodigy interested i ...

. There are six valid species in the genus. ''Amyzon'' are found in North American fossil sites dated from the

Early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

and

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

USA, as well as the

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

n sites at

McAbee Fossil Beds The McAbee Fossil Beds is a Heritage Site that protects an Eocene Epoch fossil locality east of Cache Creek, British Columbia, Canada, just north of and visible from Provincial Highway 97 / the Trans-Canada Highway ( Highway 1). The McAbee ...

, Driftwood Canyon, and the " Horsefly shale", as well as

Early Oligocene The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded b ...

sites in

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

USA. One Middle Eocene species is known from the Xiawanpu Formation of China. The Ypresian species ''A. brevipinne'' of the

Allenby Formation The Allenby formation is a sedimentary rock formation in British Columbia which was deposited during the Ypresian stage of the Early Eocene. It consists of conglomerates, sandstones with interbedded shales and coal. The shales contain an ...

was redescribed in 2021 and moved to a separate monotypic genus '' Wilsonium''.

Species

There are six valid species included in ''Amyzon'' with up to nine species having been described. * ''A. aggregatum'' Early Eocene (Ypresian), Horsefly Beds, Horsefly, B.C. * ''A. commune'' late Eocene

Florissant Formation The Florissant Formation is a sedimentary geologic formation outcropping around Florissant, Teller County, Colorado. The formation is noted for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones an ...

, Colorado (junior synonyms ''A. fusiforme'' Cope, 1875 & ''A. pandatum'' Cope, 1874 ) * ''A. gosiutensis'' Eocene

Green River Formation The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River (Colorado River), Green River in Colorado, Wyoming, and Utah. The sedimen ...

* ''A. hunanensis'' Middle Eocene, Xiawanpu Formation, China * ''A. kishenehnicum'' , Eocene,

Kishenehn Formation The Kishenehn Formation is a Paleogene stratigraphic unit in Montana. Fossil amiiforme and teleost fish have been found in outcrops of the formation's Coal Creek Member in Glacier National Park. Mosquitos have also been found in the Coal Creek Me ...

, Montana * ''A. mentale'' Oligocene, Osino Oil Shales, Nevada ;Moved from ''Amyzon'' * ''A. brevipinne'' moved to '' Wilsonium brevipinne'' , Early Eocene,

, Tulameen River, British Columbia

References

Catostomidae Prehistoric ray-finned fish genera Eocene fish of North America Oligocene fish Eocene fish of Asia Fossils of the United States Fossils of China Ypresian genus first appearances Oligocene genus extinctions Horsefly Shales Coldwater Beds Florissant Formation Taxa named by Edward Drinker Cope Fossil taxa described in 1872 {{catostomidae-stub pt:Sugador