| Changaspis Temporal range: | |
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| Changaspis elongata , lower Cambrian, Guizhou province, China | |
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| Genus: | Changaspis Lee in Chien, 1961 |
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Changaspis is an extinct genus of trilobite that lived during the lower Cambrian in what is now China.
Agnostida are an order of extinct arthropods which have classically been seen as a group of highly modified trilobites, though some recent research has doubted this placement. Regardless, they appear to be close relatives as part of the Artiopoda. They are present in the Lower Cambrian fossil record along with trilobites from the Redlichiida, Corynexochida, and Ptychopariida orders, and were highly diverse throughout the Cambrian. Agnostidan diversity severely declined during the Cambrian-Ordovician transition, and the last agnostidans went extinct in the Late Ordovician.
Ptychopariida is a large, heterogeneous order of trilobite containing some of the most primitive species known. The earliest species occurred in the second half of the Lower Cambrian, and the last species did not survive the Ordovician–Silurian extinction event.
Olenellina is a suborder of the order Redlichiida of trilobites that occurs about halfway during the Lower Cambrian, at the start of the stage called the Atdabanian. The earliest trilobites in the fossil record are arguably Olenellina, although the earliest Redlichiina,Ptychopariida, and Eodiscina follow quickly. The suborder died out when the Lower Cambrian passed into the Middle Cambrian, at the end of the stage called Toyonian. A feature uniting the Olenellina is the lack of rupture lines in the headshield, which in other trilobites assist the periodic moulting, associated with arthropod growth. Some derived trilobites have lost facial sutures again, but all of these are blind, while all Olenellina have eyes.
Redlichiina is a suborder of the order Redlichiida of Trilobites. The suborder contains three superfamilies: Emuelloidea, Redlichioidea and Paradoxidoidea. These trilobites are some of the oldest trilobites known. They originated at the beginning of the Cambrian Period and disappeared at the end of the middle Cambrian.
Terataspis is a comparatively huge, 60 centimetre long lichid trilobite genus from the Early Devonian, about 397 million years ago. It lived in a shallow sea in what is now New York State and Ontario. No whole specimens have been found, only disarticulated fragments of its exoskeleton, but enough fragments have been found to allow researchers to form reconstructions of the whole animal. The genus only contains one species, T. grandis.
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 few other Calymenina genera. They are used as an index fossil in the Ordovician. Ohio and North America are particularly known for being rich with Flexicalymene fossils.
Calymenina is a suborder of the trilobite order Phacopida.
Aulacopleura is a genus of proetid trilobite that lived from the Middle Ordovician to the Middle Devonian. Some authors may classify this group as subgenus Otarion (Aulacopleura). The cephalon 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 are present, typically reaching back to the 2nd to 4th thorax segment. The 'palate' is not connected to the dorsal shield of the cephalon. The cephalon is pitted, or has small tubercles. The thorax has up to 22 segments. The pleural ends are usually rounded. The pygidium is small (micropygous), with an even margin. A. koninckii had a modern type of compound eye.
Ogyginus is an extinct genus of asaphid trilobites that lived during the Ordovician period. Commonly found in Wales. The type specimen was first described by Murchison in 1839 as Asaphus corndensis, though the species was later reassigned.
Acanthopyge is an extinct genus of lichid trilobite that lived during the Devonian. Very few A. consanguinea from the Devonian of Oklahoma have been found, and only a handful of complete specimens from Morocco, and many so-called Acanthopyge-specimens from Morocco are fake.
Ellipsocephalus Zenker, 1833, is a genus of blind Cambrian trilobite, comprising benthic species inhabiting deep, poorly lit or aphotic habitats. E. hoffi is a common trilobite mainly from central Europe.
Harpides is an extinct genus of harpetid trilobite of the family Harpididae.
Szechuanella is an extinct genus of corynexochid trilobite that lived marine environments from the middle Cambrian to the early Ordovician in what is now China.
Calymenidae is a family of trilobites, containing the following genera:
Phillipsiidae is a family of proetid trilobites, the various genera of which comprise some of the last of the trilobites, with a range that extended from the Kinderhookian epoch of the Lower Mississippian, to the end of Changhsingian age at Permian-Triassic extinction event in the latest Permian period.
Entomaspis is an extinct genus of harpetid trilobite from Upper Cambrian to Early Ordovician marine strata of the United States. Species are typified by their proportionally large, vaulted, croissant-shaped or bonnet-shaped cephalons that have the cheeks freed to become elongated, curved librigenial spines, and by their comparatively large, crescent-shaped eyes.
Lichas is a genus of lichid trilobites from Ordovician-Devonian-aged marine strata of Europe and Morocco.
Cheirurina is a suborder of the trilobite order Phacopida. Known representatives range from the uppermost Cambrian to the end of the Middle Devonian (Givetian). Cheirurina is made up of a morphologically diverse group of related families.
Ptychopariina is an extinct suborder of trilobites of the order Ptychopariida. Also known as the primitive Ptychopariida, they are a notably wide and varied taxon. Some of the representative genera include Elrathia, Densonella, Norwoodia, Tricrepicephalus, Conocoryphe, and Modocia.
Samuel M. 'Ohukani'ōhi'a Gon III is an American scientist and cultural advisor for The Nature Conservancy of Hawaiʻi. He was born and raised in Nuʻuanu on the island of Oahu. Gon studied Hawaiian culture under Kumu John Keolamala'āinana Lake. Gon worked to integrate Hawaiian culture, values, and knowledge into conservation efforts. Gon sat on the Office of Hawaiian Affairs panel, the Hawaii Land Board (2006-2014).
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