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Proetida
Proetida is an order of trilobite that lived from the Ordovician to the Permian. It was the last surviving order of trilobite, dying out in the Permian-Triassic extinction event. Description These typically small trilobites resemble those of the order Ptychopariida, from which the new order Proetida was separated in 1975 by Richard Fortey, Fortey and Owens. Like the order Phacopida, the proetids have exoskeletons that sometime have pits or small tubercles, especially on the glabella (trilobite anatomy), glabella (middle portion of the head). Because of their resemblance to the Ptychopariida in some features, the proetids are included in the subclass Librostoma. Unlike the trilobites of the phacopid suborder Phacopina, whose trilobite eye, eyes are Eye#Apposition eyes, schizochroal, the proetids have the more common holochroal eyes. These eyes are characterized by close packing of biconvex Lens (anatomy), lenses beneath a single corneal layer that covers all of the lenses. Each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proetidae
Proetidae is a family (biology), family of Proetida, proetid trilobites. The first species appeared in the Upper Ordovician, and the last genera survived until the Middle Permian. However, if the closely related family Phillipsiidae is actually a subfamily of Proetidae, then the proetids of Proetidae survive until the end of the Permian, where the last perish during the Permian–Triassic extinction event. Genera Proetidae ostensibly contains these following genera, though many may be placed in Phillipsiidae if the latter is, indeed, a distinct family. *''Aayemenaytcheia'' *''Aceroproetus'' *''Alaskalethe'' *''Altajaspis'' *''Anambon'' *''Anglibole'' *''Angustibole'' *''Anujaspis'' *''Appendicysta'' *''Aprathia'' *''Archaeocoryphe'' *''Ascetopeltis'' *''Astroproetus'' (syn=''Xiushuiproetus'', ''Zhejiangoproetus'') *''Australokaskia'' *''Bailielloides'' *''Bapingaspis'' *''Basidechenella'' *''Beleckella'' *''Belgibole'' *''Benesovella'' *''Bitumulina'' *''Blodgettia'' *''Bohemipro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 successful of all early animals, existing in oceans for almost 270million years, with over 22,000 species having been described. Because trilobites had wide diversity and an easily fossilized mineralised exoskeleton made of calcite, they left an extensive fossil record. The study of their fossils has facilitated important contributions to biostratigraphy, paleontology, evolution, evolutionary biology, and plate tectonics. Trilobites are placed within the clade Artiopoda, which includes many organisms that are morphologically similar to trilobites, but are largely unmineralised. The relationship of Artiopoda to other arthropods is uncertain. Trilobites evolved into many ecological niches; some moved over the seabed as predators, scavengers, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropidocoryphidae
Tropidocoryphidae is an extinct family of trilobites in the order Proetida Proetida is an order of trilobite that lived from the Ordovician to the Permian. It was the last surviving order of trilobite, dying out in the Permian-Triassic extinction event. Description These typically small trilobites resemble those of .... Genera These 44 genera belong to the family Tropidocoryphidae: * '' Aidynsaia'' Owens & Ivanova, 2010 * '' Alberticoryphe'' Erben, 1966 * '' Astycoryphe'' Richter 1919 * '' Bojocoryphe'' Snajdr, 1976 * '' Buchiproetus'' Pillet, 1969 * '' Centriproetus'' Snajdr, 1977 * '' Cirriticeps'' Holloway, 2013 * '' Cornuproetus'' Richter & Richter 1919 * '' Cyrtosymboloides'' Alberti, 1967 * '' Dalejeproetus'' Snajdr, 1977 * '' Denemarkia'' Pribyl 1946 * '' Diademaproetus'' Alberti, 1964 * '' Eopiriproetus'' Alberti, 1966 * '' Galbertianus'' Özdikmen, 2006 * '' Ignoproetus'' Snajdr, 1977 * '' Interproetus'' Snajdr 1977 * '' Koneprusites'' Pribyl 1964 * '' Lepidoproe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptychopariida
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. Trilobites have facial sutures that run along the margin of the glabella and/or fixigena to the shoulder point where the cephalon meets the thorax. These sutures outline the cranidium, or the main, central part of the head that does not include the librigena (free cheeks). The eyes are medial along the glabella on the suture line (and some species have no eyes). The fossils of the moults of trilobites can often be told from the fossils of the actual animals by whether the librigena are present. (The librigena, or cheek spines, detach during moulting.) In ptychopariids, short bladelike genal spines are often present on the tips of the librigena. The thorax is large and is typically made up of eight or more segments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cummingella Belisama Dorsal Light2 CRF
''Cummingella'' is a genus of proetid trilobite in the family Phillipsiidae that lived from the earliest Carboniferous until the last species' extinction in the Middle Permian. Fossils have been found in corresponding marine strata of western Europe, the United Kingdom, and the United States. Distribution * ''C. arbizui'' was found in the Lower Carboniferous of Spain (Tournaisian, Perna Formation, 1.450 m SSE of Cerro de Perna, 5 km SE of Aliseda, Cáceres). * ''C. auge'', ''C. carringtonensis'', ''C. insulae'', and ''C. tuberculigenata'' occur at the Lower Carboniferous of the United Kingdom ( Asbian, Bee Low Limestones Formation, Treak Cliff, England). * ''C. auge'' was excavated from the earliest Carboniferous of the Czech Republic (Tournaisian, ''Scaliognathus anchoralis''-conodont zone, Brezina Formation, near Mokra village) and Germany (Tournaisian, Erdbach Limestone Formation, quarry at north-western margin of Steeden, Hessen; and quarry and slope at the Iberg-Winter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephinidae
Telephinidae is a family of pelagic trilobites with large wide-angle eyes, occupying most of the free cheeks, downward directed facial spines and 9-10 thorax segments. The family is known during the entire Ordovician and occurred in deep water around the globe. Distribution The Telephinidae probably evolved from a species assigned to the Hystricuridae. Telephinids first occur during the late Tremadocian, with ''Carolinites'' and ''Opipeuterella'' being globally very common at low latitudes by the end of the Floian. ''Carolinites'' survived into the Darriwilian, at which time a second major radiation occurred, that includes ''Telephina'' and ''Telephops'', and these genera only became extinct at the end of the Ordovician. Description The central raised area of the headshield (or glabella) is strongly convex. The most backward segment (called occipital ring) is wide and is defined by a deep furrow. No further segments can be determined in front of the occipital ring, but someti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacopida
Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders. Characteristics Phacopida had 8 to 19 thoracic segments and are distinguishable by the expanded glabella, short or absent preglabellar area, and schizochroal (Phacopina) or holochroal (Cheirurina and Calymenina) eyes. Schizochroal eyes are compound eyes with up to around 700 separate lenses. Each lens has an individual cornea which extended into a rather large sclera. The development of schizochroal eyes in phacopid trilobites is an example of post-displacement paedomorphosis. The eyes of immature holochroal Cambrian trilobites were basically miniature schizochroal eyes. In Phacopida, these were retained, via delayed growth of these immature structures (post-displacement), into the adult form. '' Eldredgeops rana'' (Phacopidae) and '' Dalmanites limulurus'' (Dalmanitidae) are two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the sixth and last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the Perm Governorate, region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the Sauropsida, sauropsids (reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aulacopleura
''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 (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 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 protist. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alokistocaridae
Alokistocaridae is a family of ptychopariid trilobites that lived from the Botomian epoch of the Early Cambrian until the Late Cambrian. Alokistocarids were particle feeders and left small furrows which are occasionally preserved.Coppold, Murray and Wayne Powell (2006). ''A Geoscience Guide to the Burgess Shale'', p.54. The Burgess Shale Geoscience Foundation, Field, British Columbia. . Their remains are found worldwide. '' Elrathia kingii'', one of the most collected trilobites in the world, is a typical alokistocarid. Description Alokistocarids have an exoskeleton that is elongated ovate to inverted egg-shaped. The headshield (or cephalon) is semicircular and has a well-defined border. The central raised area of the cephalon (or glabella) is somewhat tapering forward, generally with 3 or 4 pairs of more or less distinct lateral furrows. The front of the glabella is rounded or truncate, and is separated from the border by a wide, moderately convex to flat (or rarely concave) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
