Trilobite Flexicalymene by Nick Longrich

''Flexicalymene'' Shirley, 1936. is a genus of trilobites belonging to the order

Phacopida Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders. Characteristics Phacopida had 8 to 19 thorac ...

, suborder

Calymenina Calymenina is a suborder of the trilobite order Phacopida Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three relate ...

and Family

Calymenidae Calymenidae is a family of trilobites, containing the following genera: *'' Alcymene'' *'' Apocalymene'' *'' Arcticalymene'' *'' Calymene'' *'' Calymenella'' *'' Calymenesum'' *'' Colpocoryphe'' *'' Dekalymene'' *'' Diacalymene'' *'' Flexicalymen ...

. ''Flexicalymene'' specimens can be mistaken for ''

Calymene ''Calymene'' Brongniart, 1822, is a genus of trilobites in the order Phacopida, suborder Calymenina, that are found throughout North America, North Africa, and Europe in primarily Silurian outcrops. ''Calymene'' is closely related to ''Flexicaly ...

'', '' Gravicalymene'', '' Diacalymene'' and a few other

genera. They are used as an index fossil in the

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. ...

. Ohio and North America are particularly known for being rich with ''Flexicalymene'' fossils.

Diagnosis

"Glabella parabolic to bell-shaped in outline, with three or four lateral lobes and furrows. Lacks buttress(es) from fixed cheek to lateral glabellar lobe(s). Does not have preglabellar field. No distinct crescentic area outside lateral lobe l p. Facial sutures gonatoparian (exceptionally, can be proparian in Flexicalymene). Genal spines absent. Hypostome without discrete protuberance on anterior lobe of median body." (Siveter, 1976, p.353)

Type species

* ''Flexicalymene caractaci'' ( Salter, 1865). By original designation and by monotypy, ''Calymene blumenbachii'' var. ''Caractaci'' Salter, 1865 from the Marshbrookian, ''Dalmanella unguis'' Biozone (

Caradoc Series In geology, Caradoc Series is the name introduced by Roderick Murchison in 1839 for the sandstone series of Caer Caradoc in Shropshire, England. It is the fifth of the six subdivisions (in ascending order) of the Ordovician System, comprising all t ...

) of Marshwood Quarry, near Marshbrook,

Shropshire Shropshire (; alternatively Salop; abbreviated in print only as Shrops; demonym Salopian ) is a landlocked historic county in the West Midlands region of England. It is bordered by Wales to the west and the English counties of Cheshire to ...

, England.

Other species

* ''Flexicalymene cambrensis'' (Salter, 1865), from the Lower Llandeilo Group of Llan Mill, near Narberth,

Dyfed Dyfed () is a preserved county in southwestern Wales. It is a mostly rural area with a coastline on the Irish Sea and the Bristol Channel. Between 1974 and 1996, Dyfed was also the name of the area's county council and the name remains in use ...

Wales Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...

. * ''Flexicalymene acantha'' Bancroft, 1949, from the Harnage Shale Formation (Harnagian Stage), near Horderley, Shropshire, England. * ''Flexicalymene incerta'' Barrande, 1852, Found only at Lower part of wooded slope above railroad facing Přeštínská Railway Station (Ordovician of Czech Republic). Assigned by Dean (1963). * ''Flexicalymene planimarginata'' (Reed, 1906), from the Lower Longvillian (Caradoc Series) of Ynys Galed, 4 km west of

Dolbenmaen Dolbenmaen () is a village and community in the Welsh county of Gwynedd, located in Eifionydd, of which it was the administrative centre until 1239. The community includes the villages of Bryncir (), Cenin, Garndolbenmaen, (the largest settleme ...

Gwynedd Gwynedd (; ) is a Local government in Wales#Principal areas, county and preserved county (latter with differing boundaries; includes the Isle of Anglesey) in the North West Wales, north-west of Wales. It shares borders with Powys, Conwy County B ...

, Wales. * ''Flexicalymene cavei'' Price, 1974, from a Cautleyan marine limestone in the Sholeshook Formation of Moldin, near Llanddowror,

Carmarthenshire Carmarthenshire ( cy, Sir Gaerfyrddin; or informally ') is a county in the south-west of Wales. The three largest towns are Llanelli, Carmarthen and Ammanford. Carmarthen is the county town and administrative centre. The county is known ...

, Wales. * ''Flexicalymene shirleyi'' Tripp, 1954. From mudstone in the Ardwell Group, Balclatchie Formation (Caradoc Series) of Craighead Quarry near Girvan, Ayrshire, Scotland. * ''Flexicalymene scotica'' Lamont, (1949, p. 315, P1. 18, figs. 6, 7), uppermost Ordovician (Hirnantian), Girvan, Ayrshire, Scotland. * ''Flexicalymene verecunda'' Dean, 1979. From limestone/shale on unsurfaced road leading from Lourdes to Clam Bank Cove in the Long Point Group (Ordovician) and Winterhouse Formation,

Port au Port Peninsula The Port au Port Peninsula (french: péninsule de Port-au-Port; mic, Kitpu) is a peninsula in the Canadian province of Newfoundland and Labrador. Roughly triangular in shape, it is located on the west coast of the island of Newfoundland. Geogr ...

, southwestern Newfoundland, Canada. * ''Flexicalymene croneisi'' Roy, 1941. Upper Ordovician,

Baffin Island Baffin Island (formerly Baffin Land), in the Canadian territory of Nunavut, is the largest island in Canada and the fifth-largest island in the world. Its area is , slightly larger than Spain; its population was 13,039 as of the 2021 Canadi ...

, (

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...

). * ''Flexicalymene meeki'' Foerste, 1910. From the Ordovician of Ontario and

Quebec Quebec ( ; )According to the Government of Canada, Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is ...

in Canada 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 ...

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virgini ...

Michigan Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...

Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...

and

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to ...

in the USA. * ''Flexicalymene retrorsa'' Foerste, 1910. Type locality is half a mile above the mouth of Silver creek, east of Dunlapsville, Late Ordovician (Richmondian)

Waynesville Formation The Waynesville Formation is a geologic formation in Ohio and Indiana. It preserves fossils from the Late Ordovician period. See also * List of fossiliferous stratigraphic units in Ohio * List of fossiliferous stratigraphic units in Indiana ...

of Indiana. The species is also recorded from Quebec, Canada and Ohio, Kentucky USA. * ''Flexicalymene granulosa'' (Ohio, Kentucky and Quebec). * ''Flexicalymene senaria'' Conrad, 1841.CONRAD, T. A. 1841. Fifth annual report on the paleontology of the state of New York. ''New York Geological Survey, Annual Report'' 5: pp. 25 - 57 From the Ordovician of Canada (Ontario, Quebec, Québec), Sweden, United States (Illinois,

Iowa Iowa () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wiscon ...

, Michigan,

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the List of U.S. states and territories by population, 22nd most populous, with over 5.75 million residents. Minne ...

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

, Tennessee and

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the East Coast of the United States, Atlantic Coast and the Appalachian Mountains. The geography an ...

. * ''Flexicalymene ouzregui'' Ordovician, Morocco. * ''Flexicalymene tazarensis'' Ordovician, Morocco.

Gallery

File:Flexicalymene meeki cephalon view.JPG, ''Flexicalymene meeki'';

; Upper Ordovician; Caesar Creek,

. Image:Flexicalymene meeki pygidium view.JPG, ''Flexicalymene meeki''; Waynesville Formation; Upper Ordovician; Caesar Creek, Ohio. File:Flexicalimene_Meeki.jpg, ''F. meeki'' File:Flexicalymene_PAStateMuseum.jpg, ''Flexicalymene'' species on display at

State Museum of Pennsylvania The State Museum of Pennsylvania is a non-profit museum at 300 North Street in downtown Harrisburg, Pennsylvania. It is run by the state through the Pennsylvania Historical and Museum Commission and was created to preserve and interpret the region ...

. Specimen is approximately 3 cm long File:Flexicalymene-ouzregui-rolled.jpg, Rolled ''F. ouzregui''

References

External links

'' Trilobite info (Sam Gon III)''
Calymenidae Ordovician trilobites Silurian trilobites Fossils of Ireland Fossils of Sweden Ordovician first appearances Silurian extinctions Fossils of Georgia (U.S. state) Paleozoic life of Ontario Verulam Formation Paleozoic life of Nunavut Paleozoic life of Quebec {{phacopida-stub