''Gravicalymene'' 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 related ...

and family

Calymenidae Calymenidae is a family of trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the ...

. Species included in this genus have previously been allocated to ''

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 ...

'' Brongniart 1822,''

Flexicalymene ''Flexicalymene'' Shirley, 1936. is a genus of trilobites belonging to the order Phacopida, suborder Calymenina and Family Calymenidae. ''Flexicalymene'' specimens can be mistaken for '' Calymene'', ''Gravicalymene'', '' Diacalymene'' and a fe ...

'' Shirley, 1936. and '' Sthenarocalymene'' Siveter 1977. Rarest within the genus is the Middle Ordovician species ''Gravicalymene magnotuberculata'', which is also amongst the rarest of all

and regionally confined to two exposures in New York State. ''G. magnotuberculata'' is noted for its extremely pustulose exoskeleton, bell-shaped glabella and lack of complete articulated specimens.

Type species

* '' Gravicalymene convolva'' Shirley 1936, by original designation. Found only in the Birdshill Limestone (Pusgillian or lowest Cautleyan Stage) at Birdshill Quarry, near

Llandeilo Llandeilo () is a town and community in Carmarthenshire, Wales, situated at the crossing of the River Towy by the A483 on a 19th-century stone bridge. Its population was 1,795 at the 2011 Census. It is adjacent to the westernmost point of the B ...

South Wales South Wales ( cy, De Cymru) is a loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the historic counties of Glamorgan and Monmouthshire, south Wales extends westwards ...

Other species

Some known species and locations include: * ''

Gravicalymene arcuata ''Gravicalymene'' Shirley, 1936, is a genus of trilobites belonging to the order Phacopida, suborder Calymenina and family Calymenidae. Species included in this genus have previously been allocated to ''Calymene'' Brongniart 1822,''Flexicalymene ...

'' Price, 1982. Rawtheyan Stage,

Dolhir Formation The Dolhir Formation is a geologic formation in Wales. It preserves fossils dating back to the Ordovician period. See also * List of fossiliferous stratigraphic units in Wales This is a list of fossiliferous stratigraphic units in Wales. ...

, Cynwyd Forest Quarry, Denbighshire, North Wales, UK. * ''Gravicalymene pontillis'' Price, 1982. From the upper Cautleyan and lower Rawtheyan of the Berwyn Range and near Conway, North Wales. * ''Gravicalymene quadrata'' (King, 1923), from the Rawtheyan Zone 7 at Craig-Fawr Llanfyllyn and the Meifod area. (see Price, 1982). Transferred to ''Sthenarocalymene'' sp. nov. by Siveter (1977, p. 386). * ''Gravicalymene praecox'' Bancroft, 1949, from the Smeathen Wood Beds (Harnagian Stage, ''Reuscholithus reuschi'' Biozone) near Horderley,

Wistanstow Wistanstow is a village and parish in Shropshire, England. Wistanstow is located about south of Church Stretton and north of Ludlow. It is about north of Craven Arms. It is just off the main Shrewsbury- Hereford road, the A49. The large par ...

, Shropshire, England. * ''Gravicalymene jugifera'' Dean, 1962, from the pusgillian and lowermost Cautleyan in Northern England. * ''Gravicalymene inflata'' Dean, 1963. The only known specimen is from the Onnian Stage, ''Onnia gracilis'' Zone, in the north bank of the River Onny, 100 yards east of its junction with Batch Gutter (on the A489 Horderley road, 1 km from its junction with the A49 near

, Shropshire). * '' Gravicalymene capitovata'' Siveter, 1977 From the Middle Ordovician of the Oslo Region, Norway. * ''Gravicalymene quadrilobata'' Chatterton 1971. Its type locality is Chatterton Loc. C, ''Spirifer yassensis'' Lst, near Yass, NSW, which is in an early Devonian (

Emsian The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 407.6 ± 2.6 million years ago to 393.3 ± 1.2 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after the ...

) marine limestone in the Taemas Formation of Australia. * ''Gravicalymene yamakoshii'' Kobayashi & Hamada, 1977. From the Devonian of Japan. * '' Gravicalymene abbreviata'' (Foerste, 1910), southwestern Ohio, southeastern Indiana, and northern Kentucky. * '' Gravicalymene bakeri'' (Smith & Ebach, 2020), from Late Ordovician shales of the Gordon Group in northern Tasmania. Named after

Doctor Who ''Doctor Who'' is a British science fiction television series broadcast by the BBC since 1963. The series depicts the adventures of a Time Lord called the Doctor, an extraterrestrial being who appears to be human. The Doctor explores the u ...

actor

Tom Baker Thomas Stewart Baker (born 20 January 1934) is an English actor and writer. He is well known for his portrayal of the Fourth Doctor, fourth incarnation of The Doctor (Doctor Who), the Doctor in the science fiction television series ''Doctor Wh ...

. * '' Gravicalymene hagani'' Ross and Barnes, 1967, Lexington Limestone, ''Salvisa'' Bed of the Lexington Limestone, 21 feet below base of Clays Ferry Formation. Section 30B (Perryville South), North America. Also Iran. * '' Gravicalymene magnotuberculata'' (Ruedemann, 1926), from 2 localized bedding planes in the Denley Limestone, Trenton Group (Middle Ordovician), Herkimer County, New York State, United States. * '' Gravicalymene truncatus'' Ross, 1979. Only found at its type locality, USGS 7984-CO, along Moffett Road, 0.5 miles west of Kenton, which is in an Edenian offshore ramp packstone/mudstone in the Kope Formation of Kentucky, USA.

References

Calymenidae Silurian trilobites Fossils of the United States Ordovician first appearances Devonian extinctions Paleozoic life of Quebec Ordovician trilobites of Australia Fossils of Wales {{phacopida-stub