Redlichiida is an order within the major extinct arthropod class Trilobita. The Redlichids are one of the four older classes of trilobites that originated in the Lower Cambrian. Superfamilies Superfamily Olenelloidea Olenellidae Mesonacis vermontanus Holmiidae Superfamily Fallotaspidoidea Archaeaspididae Fallotaspididae Judomiidae Neltneriidae Nevadiidae Nevadia Olenellina is a suborder of the order Redlichiida of Trilobites. ... Superfamilies Superfamily Emuelloidea Superfamily Redlichioidea Abadiellidae Chengkouaspidae Dolerolenidae Gigantopygidae Kuechowiidae Mayiellidae Menneraspididae Metadoxididae Redlichiidae Redlichiidae Redlichia takooensis Saukiandidae Yinitidae Superfamily Paradoxidoidea Centropleuridae Paradoxididae Paradoxides Xystriduridae Redlichiina is a suborder of the order Redlichiida of Trilobites. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - Trilobites (extinct) Subphylum Chelicerata Arachnida - Spiders, Scorpions, etc. ... Orders Agnostida Redlichiida Corynexochida Lichida Nektaspida? Phacopida Proetida Asaphida Harpetida Ptychopariida Trilobites are extinct arthropods in the class Trilobita. ... The Cambrian is a major division of the geologic timescale that begins about 542 million years before the present (BP) at the end of the Proterozoic eon and ended about 490 million years BP with the beginning of the Ordovician period. ...

Redlichid trilobites are the first arthropods to appear in the fossil record. The earliest known trilobite seems to be the genus Fallotaspis, which is a Redlichid. They are common fossils in Lower Cambrian faunas worldwide. They die out before the end of the Middle Cambrian. The two major Lagerstätten, at which Redlichids are found, are the Emu Bay shales of Southern Australia and the Maotianshan shales near Chengjiang in China. A fossil Ammonite Fossils are the mineralized remains of animals or plants or other traces such as footprints. ... In biology, a genus (plural genera) is a grouping in the classification of living organisms having one or more related and morphologically similar species. ... Fauna is a collective term for animal life. ... Lagerstätten (German; singular Lagerstätte; literally place of storage, resting place) are sedimentary deposits that exhibit extraordinary fossil richness or completeness. ... North Coast of Kangaroo Island, Emu Bay © David Simpson The Emu Bay shale formation is one of two major Konservat-Lagerstätten (fossil beds with soft tissue preservation) in the world containing fossilised Redlichiida, an order of trilobite. ... The Maotianshan shale is an early Cambrian rock formation exposed in the Yunnan Province of China in the villages of Ercaicun and Chengjiang near the city of Kunming. ...

Physical description

(See the Trilobite article for a definition of morphological terms) Orders Agnostida Redlichiida Corynexochida Lichida Phacopida Proetida Asaphida Harpetida Ptychopariida doubtful order Nektaspida Trilobites are extinct arthropods in the class Trilobita. ...

Redlichids look primitive. They typically have a large, semicircular cephalon and a highly-segemented thorax that tapers back to a small pygidium. Unlike many other trilobite orders, the Redlichids were probably not capable of defensive enrollment. The Redlichids generally have prominent, long, crescent-shaped eyes. The Redlichids are often quite spiny with genal, and/or glabular, and/or tail, and/or segment spines. One Redlichid family, the Olenellids, typically have long spines on the third thoracic segment. The cephalon is the foremost portion of the segmented body of a trilobite. ... Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body that lies between the head and the abdomen. ... The pygidium is the posterior body part or shield of crustaceans, some insects, and trilobites. ...

The appendages have been preserved in a few specimens. They follow typical trilobite patterns in terms of the number, placement, and types of legs, antennae, gills, etc. gills of a Smooth Newt In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ...

Suborders

The Redlichiids are divided into two suborders: Olenellina and Redlichiina. Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Superfamilies Superfamily Olenelloidea Olenellidae Mesonacis vermontanus Holmiidae Superfamily Fallotaspidoidea Archaeaspididae Fallotaspididae Judomiidae Neltneriidae Nevadiidae Nevadia Olenellina is a suborder of the order Redlichiida of Trilobites. ... Superfamilies Superfamily Emuelloidea Superfamily Redlichioidea Abadiellidae Chengkouaspidae Dolerolenidae Gigantopygidae Kuechowiidae Mayiellidae Menneraspididae Metadoxididae Redlichiidae Redlichiidae Redlichia takooensis Saukiandidae Yinitidae Superfamily Paradoxidoidea Centropleuridae Paradoxididae Paradoxides Xystriduridae Redlichiina is a suborder of the order Redlichiida of Trilobites. ...

The Olenellids are found in North America and associated areas that comprised the Cambrian continent of Laurentia. They are very common and are used to define the scope of Laurentia. Their abrupt disappearance marks the Lower-Middle Cambrian boundary in areas where the Olenellids are found. Olenellids do not have a facial suture. World map showing North America A satellite composite image of North America North America is a continent in the northern hemisphere bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west by the... Laurentia is the craton at the heart of North America. ...

Members of suborder Redlichiina are associated with Cambrian regions other than Laurentia. They have facial sutures and their remains are frequently found without their librigena, or "free cheeks". The relatively uncommon Bathynotids had facial sutures, long genal spines, and long spines on the final thoracic segment.