The Cambrian is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran period 538.8 Ma to the beginning of the Ordovician Period 485.4 Ma.
Trilobites 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 fossil record defines the base of the Atdabanian stage of the Early Cambrian period and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last trilobites disappeared in the mass extinction at the end of the Permian about 251.9 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described.
Balcoracania dailyi is a small trilobite of the family Emuellidae. Its fossils have been found in south Australia and Antarctica.
Frederick William Whitehouse was a noted geologist, born in Ipswich, Queensland, Australia.
Redlichia is a genus of redlichiid trilobite in the family Redlichiidae, with large to very large species. Fossils of various species are found in Lower Cambrian (Toyonian)-aged marine strata from China, Korea, Pakistan, the Himalayas, Iran, Spain, southern Siberia, and Antarctica, and from Middle Cambrian (Ordian)-aged marine strata of Australia.
Anomalocaris is an extinct genus of radiodont, an order of early-diverging stem-group arthropods.
The geology of Antarctica covers the geological development of the continent through the Archean, Proterozoic and Phanerozoic eons.
Naraoia is a genus of small to average size marine arthropods within the family Naraoiidae, that lived from the early Cambrian to the late Silurian period. The species are characterized by a large alimentary system and sideways oriented antennas.
Misszhouia is a genus of small to average sized marine trilobite-like arthropods within the Naraoiidae family, that lived during the early Cambrian period. The species are M. longicaudata, from the Maotianshan Shales, described in 1985, and M. canadensis, from the Burgess Shale and described in 2018, although later species may belongs to genus Naraoia instead.
Acontheus is a genus of trilobites belonging to the Family Corynexochidae, Order Corynexochida, and is geographically widespread having been recorded from middle Cambrian strata in Sweden, Newfoundland, Germany, Siberia, Antarctica, Queensland, China and Wales.
Chelediscus Rushton, 1966, is a genus of Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida Salter (1864). The Treatise assigns this genus to the Calodiscidae; Cotton and Fortey (2005) however move it to the Weymouthiidae. Chelediscus lived during the later part of the Botomian stage.
Peronopsis is a genus of trilobite restricted to the Middle Cambrian. Its remains have been found in Asia, Australia, Europe, and North America.
Redlichiidae is a family of redlichiid trilobites which lived from the Botomian to the Middle Cambrian period. It contains the following genera, divided between five subfamilies:
Salterella is an enigmatic Cambrian genus with a small, conical, calcareous shell that appears to be septate, but is rather filled with stratified laminar deposits. The shell contains grains of sediment, which are obtained selectively by a manner also observed in foramanifera. The genus was established by Elkanah Billings in 1861, and was named after the English palaeontologist John William Salter.
The Miaolingian is the third Series of the Cambrian Period, and was formally named in 2018. It lasted from about 509 to 497 million years ago and is divided in ascending order into 3 stages: the Wuliuan, Drumian, and Guzhangian. The Miaolingian is preceded by the unnamed Cambrian Series 2 and succeeded by the Furongian series.
Glyptagnostus reticulatus is a species of agnostid trilobite belonging to the genus Glyptagnostus. It existed during the Paibian Age of the Cambrian. It has a cosmopolitan distribution and is an important index fossil in biostratigraphy. It was characterized by an unusual net-like pattern of furrows on both the cephalon and the pygidium.
Cambrian Series 2 is the unnamed 2nd series of the Cambrian. It lies above the Terreneuvian series and below the Miaolingian. Series 2 has not been formally defined by the International Commission on Stratigraphy, lacking a precise lower boundary and subdivision into stages. The proposed lower boundary is the first appearance of trilobites which is estimated to be around 521 million years ago.
Itagnostus is a genus of trilobite restricted to the Middle Cambrian. Its remains have been found in Asia, Australia, Europe, and North America.
The Shackleton Limestone is a Cambrian limestone formation of the Byrd Group of Antarctica. The age of the formation is established to be Cambrian Stage 3, dated at ranging from 520 to 516 Ma. This period correlates with the End-Botomian mass extinction. Fossils of trilobites and Marocella mira and Dailyatia have been found in the formation, named after Ernest Shackleton, who led a failed expedition into Antarctica. At time of deposition, the Antarctic Plate has been established to be just south of the equator as part of the supercontinent Pannotia, contrasting with its present position at 82 degrees southern latitude.
Serrodiscus Richter and Richter 1941. is a genus of Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida. It lived during the late Lower Cambrian, with remains found in Canada, China (Gansu), The United Kingdom (England), Germany (Silesia), Poland, the Russian Federation, and the United States. It is named for the spines on the ventral side of the pygidium, which give it a serrated impression.
