''Sphaerexochus'' 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 ...

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 ...

s from the Middle

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

to Late

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 ...

(468.1 to 418.7 Ma) of

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. The type species of the genus is ''Sphaerexochus mirus'' Beyrich 1845 (syn. of ''Sphaerexochus calvus'' Mc Coy 1846) . Similar and related genus is '' Pseudosphaerexochus''.

Species

* ''Sphaerexochus arenosis'' Chatterton and Ludvigsen 1977 * ''Sphaerexochus arenosus'' Chatterton and Ludvigsen 1976 * ''Sphaerexochus atacius'' Ludvigsen 1979 * ''Sphaerexochus brandlyi'' Chatterton and Perry 1984 * ''Sphaerexochus bridgei'' Cooper and Kindle 1936 * ''Sphaerexochus britanicus'' Dean 1971 * ''Sphaerexochus calvus'' Mc Coy 1846 * ''Sphaerexochus dimorphus'' Whittington and Evitt 1953 * ''Sphaerexochus eurys'' Tripp 1962 * ''Sphaerexochus fibrisulcatus'' Lu 1975 * ''Sphaerexochus glaber'' Holloway 1980 * ''Sphaerexochus hapsidotus'' Whittington and Evitt 1953 * ''Sphaerexochus hiratai'' Kobayashi and Hamada 1964 * ''Sphaerexochus hisingeri'' Warburg 1925 * ''Sphaerexochus johnstoni'' Chatterton and Perry 1984 * ''Sphaerexochus laciniatus'' Lindström 1885 * ''Sphaerexochus latifrons'' Angelin 1854 * ''Sphaerexochus molongloensis'' Chatterton and Campbell 1980 * ''Sphaerexochus parvus'' Billings 1865 * ''Sphaerexochus pulcher'' Whittington and Evitt 1953 * ''Sphaerexochus romingeri'' Hall 1868 * ''Sphaerexochus scabridus'' Angelin 1854 * ''Sphaerexochus tuberculatus'' Warburg 1925 * ''Sphaerexochus valcourensis'' Shaw and Bolton 2011

References

* ''Fossils'' (Smithsonian Handbooks) by David Ward (Page 59)
''Sphaerexochus''
in the

Paleobiology Database The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ...

Cheiruridae Phacopida genera Ordovician trilobites Silurian trilobites Paleozoic animals of Asia Trilobites of Oceania Trilobites of Europe Trilobites of North America Darriwilian first appearances Silurian extinctions Paleozoic life of the Northwest Territories Paleozoic life of Nunavut Paleozoic life of Quebec {{phacopida-stub