''Aulacopleura'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of proetid

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

that lived from the

Middle Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era, and the second of twelve periods of the Phanerozoic Eon. The Ordovician spans 41.6 million years from the end of the Cambrian Period Ma (milli ...

to the

Middle Devonian In the geological timescale, the Middle Devonian epoch (from 393.3 ± 1.2 million years ago to 382.7 ± 1.6 million years ago) occurred during the Devonian period, after the end of the Emsian age. The Middle Devonian epoch is subdivided into two ...

. Some authors may classify this group as subgenus ''Otarion (Aulacopleura)''. The

cephalon Cephalon, Inc. was an American biopharmaceutical company co-founded in 1987 by pharmacologist Frank Baldino Jr., Frank Baldino, Jr., neuroscientist Michael Lewis, and organic chemist James C. Kauer—all three former scientists with the DuPont ...

is semicircular or semielliptical, with border and preglabellar field. The glabella is short, with or without defined eye ridges connecting it with eyes of variable size. Spines at the rear outer corners of the cephalon (or genal spines) are present, typically reaching back to the 2nd to 4th thorax segment. The 'palate' (or hypostome) is not connected to the dorsal shield of the cephalon (or natant). The cephalon is pitted, or has small tubercles. The thorax has up to 22 segments. The pleural ends are usually rounded. The

pygidium The pygidium (: pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is compos ...

is small (micropygous), with an even margin. ''A. koninckii'' had a modern type of compound eye.

Taxonomy

Barrande described ''Arethusa koninckii'' in 1846. However, ''Arethusa'' was occupied since it was used by De Montfort in 1808 for a

foram Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of Rhizarian protists characterized by streaming granular ectoplasm for catching food and other uses; and commonl ...

protist A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancest ...

. Barrande tried to correct this by proposing ''Arethusina'' as a replacement, but by that time that Hawle and Corda had already suggested ''Aulacopleura'' in 1847, which is thus the senior available name.

Distribution

* ''A. andersoni'' Adrian & Chatterton, 1995 - from the

Lower Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

(Late Telychian, Upper Whittaker Formation,

Mackenzie Mountains The Mackenzie Mountains are a Canadian mountain range forming part of the Yukon–Northwest Territories boundary between the Liard and Peel rivers. The range is named in honour of Canada's second prime minister, Alexander Mackenzie. Nahanni ...

) * '' A. koninckii'' is known from the Middle Silurian of the Czech Republic ( Wenlockian, Liten Formation, Bohemia). * ''A. krizi'' Snajdr, 1975 - Lower Silurian Bohemia ( Želkovice formation,

Beroun Beroun (; ) is a town in the Central Bohemian Region of the Czech Republic. It has about 22,000 inhabitants. It lies at the confluence of the Berounka and Litavka rivers. Beroun creates a conurbation with Králův Dvůr, former part of Beroun. ...

region, Central Bohemia)BioLib
Aulacopleura krizi Šnajdr, 1975^†
/ref> * ''A. letmathensis'' has been found in the

of Germany (

Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in ...

). * ''A. pogsoni'' was collected from Lower Silurian of Australia (late

Llandovery Llandovery (; ) is a market town and community (Wales), community in Carmarthenshire, Wales. It lies on the River Tywi and at the junction of the A40 road, A40 and A483 road, A483 roads, about north-east of Carmarthen, north of Swansea and w ...

, upper Cotton Formation, near Forbes, New South Wales). * ''A. wulongensis'' occurs in the Lower Silurian of China (

, Sichuan).)

References

Sources

'' Trilobite info (Sam Gon III)''
{{Taxonbar, from=Q4821694 Proetida genera Ordovician trilobites Silurian trilobites of Europe Devonian trilobites of Europe Fossils of China Fossils of the Czech Republic Fossils of Germany Trilobites of Australia Silurian trilobites of Asia Silurian trilobites of Oceania Dapingian first appearances Middle Devonian genus extinctions Paleozoic life of the Northwest Territories Paleozoic life of Nunavut Fossil taxa described in 1846

Taxonomy

Distribution

See also

References

Sources