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Cheirurina
Cheirurina is a suborder of the trilobite order Phacopida. Known representatives range from the uppermost Cambrian (upper Furongian) to the end of the Middle Devonian (Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in Fra ...). Cheirurina is made up of a morphologically diverse group of related families. References Phacopida Prehistoric animal suborders Arthropod suborders Cambrian trilobites Ordovician trilobites Silurian trilobites Devonian trilobites Furongian first appearances Givetian extinctions {{phacopida-stub ... [...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 tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheirurina
Cheirurina is a suborder of the trilobite order Phacopida. Known representatives range from the uppermost Cambrian (upper Furongian) to the end of the Middle Devonian (Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in Fra ...). Cheirurina is made up of a morphologically diverse group of related families. References Phacopida Prehistoric animal suborders Arthropod suborders Cambrian trilobites Ordovician trilobites Silurian trilobites Devonian trilobites Furongian first appearances Givetian extinctions {{phacopida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheiruridae
Cheiruridae is a family of phacopid trilobites of the suborder Cheirurina. Its members, as with other members of the suborder, had distinctive pygidia modified into finger-like spines. They first appeared in the uppermost Cambrian (upper Furongian), and persisted until the end of the Middle Devonian (Givetian). Currently about 657 species assigned to 99 genera are included. Distribution The subfamily Cheirurinae with 269 species in 38 genera occur from the Floian to the Givetian and are probably monophyletic. The 109 species in 15 genera of the Acanthoparyphinae are also probably monophyletic, and are known from the Floian to the Ludfordian. The Cyrtometopinae were present between the Floian and the Upper Katian, enveloping 22 species in 5 genera, of which the monophyly is unclear. The Deiphoninae are probably monophyletic, occur from the Dapingian to the Gorstian, having 71 species assigned to 6 genera. The possibly paraphyletic Eccoptochilinae with 67 species in 13 genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilekiidae
Pilekiidae is a family of trilobites in the order Phacopida, specifically within Suborder Cheirurina. It includes the following genera: *'' Anacheiruraspis'' *''Anacheirurus'' *'' Chashania'' *''Demeterops'' *''Emsurina'' *'' Koraipsis'' *''Landyia'' *''Macrogrammus ''Macrogrammus'' is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the early part of the Arenig, Arenig stage of the Ordovician Period, a faunal stage which lasted from approximately 478 to 4 ...'' *'' Metapilekia'' *'' Metapliomerops'' *'' Parapilekia'' *'' Pilekia'' *'' Pliomeroides'' *'' Pseudopliomera'' *'' Seisonia'' *'' Sinoparapilekia'' *'' Victorispina'' References Trilobite families {{phacopida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceraurus Pleurexanthemus
''Ceraurus'' is a genus of cheirurid trilobite of the middle and, much more rarely, the upper Ordovician. They are commonly found in strata of the lower Great Lakes region. These trilobites have eleven thoracic segments, a very small pygidium and long genal and pygidial spines. ''Ceraurus'' is quite common in the Ordovician of upstate New York, south-central and south-eastern Ontario, and the St. Lawrence Valley in Quebec, as well as in the Canadian Arctic. It and similar genera range in size from less than quarter an inch to well over five inches. Similar genera of trilobites occur in the Ordovician outcrops of the Volkhov River, near St. Petersburg, Russia. The taxonomy of the genus is problematic, as the many variations of eye placement, decoration patterns of pustules, and spine length call the genus' defining characteristics into question. ''Ceraurus'' may, in fact, be at least four genera: ''Ceraurus'' sensu stricto, and the genera, ''Gabriceraurus'', ''Bufoceraurus'' and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Trilobites
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian Trilobites
The Silurian ( ) is a geologic period and system spanning 24.6 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 shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone durin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Trilobites
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian Pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Trilobites
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod Suborders
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chitin, often mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior organs; it has an open circulatory system. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. Their nervous system is "ladder- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Animal Suborders
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
