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Encyclopedia > Devonian
Artist's illustration of a Devonian scene.
Artist's illustration of a Devonian scene.

The Devonian is a geologic period of the Paleozoic era spanning from roughly 416 to 359 million years ago. It is named after Devon, England, where rocks from this period were first studied. Southwestern Brythonic is one of two dialects into which the Brythonic language split following the Battle of Deorham in 577 CE; the other being Western Brythonic, which later evolved into Welsh and Cumbric. ... Part of the seafront of Torquay, south Devon, at high tide Devon is a large county in South West England, bordered by Cornwall to the west, and Dorset and Somerset to the east. ... Image File history File links Size of this preview: 636 × 448 pixelsFull resolution (636 × 448 pixel, file size: 27 KB, MIME type: image/jpeg) From [1] File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Devonian ... Image File history File links Size of this preview: 636 × 448 pixelsFull resolution (636 × 448 pixel, file size: 27 KB, MIME type: image/jpeg) From [1] File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Devonian ... A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. ... The Paleozoic Era (from the Greek palaio, old and zoion, animals, meaning ancient life) is the earliest of three geologic eras of the Phanerozoic eon. ... Part of the seafront of Torquay, south Devon, at high tide Devon is a large county in South West England, bordered by Cornwall to the west, and Dorset and Somerset to the east. ... For other uses, see England (disambiguation). ...


During the Devonian Period, which occurred in the Paleozoic era, the first fish evolved legs[1]and started to walk on land as tetrapods around 365 Ma, and the first insects and spiders also started to colonize terrestrial habitats. For other uses, see Fish (disambiguation). ... To meet Wikipedias quality standards, this article or section may require cleanup. ... A landform comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography. ... Groups See text. ... Mega-annum, usually abbreviated as Ma, is a unit of time equal to one million years. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... Diversity 111 families, 40,000 species Suborders Mesothelae Mygalomorphae Araneomorphae  See table of families Wikispecies has information related to: Spiders Spiders are predatory invertebrate animals that have two body segments, eight legs, no chewing mouth parts and no wings. ... Habitat (which is Latin for it inhabits) is the place where a particular species live and grow. ...


The first seed-bearing plants spread across dry land, forming huge forests. In the oceans, primitive sharks became more numerous than in the Silurian and the late Ordovician, and the first lobe-finned and bony fish. The first ammonite mollusks appeared, and trilobites, the mollusc-like brachiopods, as well as great coral reefs were still common. The Late Devonian extinction severely affected marine life. Divisions Pinophyta (or Coniferophyta) - Conifers Ginkgophyta - Ginkgo Cycadophyta - Cycads Gnetophyta - Gnetum, Ephedra, Welwitschia The gymnosperms (Gymnospermae) are a group of spermatophyte seed-bearing plants with ovules on the edge or blade of an open sporophyll, the sporophylls usually arranged in cone-like structures. ... This article is about a community of trees. ... Animated map exhibiting the worlds oceanic waters. ... For other uses, see Shark (disambiguation). ... The Silurian is a major division of the geologic timescale that extends from the end of the Ordovician period, about 443. ... The Late Ordovician, also called the Upper Ordovician by geologists, is the third epoch of the Ordovician period. ... Subclasses Coelacanthimorpha - Coelacanths Dipnoi - Lungfishes Tetrapoda Sarcopterygii is traditionally the class of lobe-finned fishes, consisting of lungfish and coelacanths. ... Subclasses Actinopterygii Sarcopterygii Osteichthyes are the bony fish, a group paraphyletic to the land vertebrates, which are sometimes included. ... For other uses, see Ammonite (disambiguation). ... Classes Caudofoveata Aplacophora Polyplacophora Monoplacophora Bivalvia Scaphopoda Gastropoda Cephalopoda † Rostroconchia The mollusks or molluscs are the large and diverse phylum Mollusca, which includes a variety of familiar creatures well-known for their decorative shells or as seafood. ... For the robot vacuum cleaner, see Electrolux Trilobite. ... Diversity About 4000 genera Subphyla and classes See Classification Brachiopods (from Latin bracchium, arm + New Latin -poda, foot) are a nearly extinct, small phylum of benthic invertebrates. ... Some of the biodiversity of a coral reef, in this case the Great Barrier Reef, Australia. ... Comparison of the three episodes of extinction in the Late Devonian (Late D) to other mass extinction events in Earths history. ...


The paleogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, and the early formation of the small supercontinent of Euramerica in the middle. Palaeogeography is the study of the ancient geography of the Earths surface. ... In geology, a supercontinent is a land mass comprising more than one continental core, or craton. ... For other uses of Gondwana and Gondwanaland, see Gondwana (disambiguation). ... Animated, colour-coded map showing the various continents. ... Siberia (Sometimes called Angara) is the craton located in the heart of the region of Siberia. ... Euramerica (also known as Laurussia) was a minor supercontinent created in the Devonian by the collision of Laurentia and Baltica (Scandian Orogeny). ...

Contents

Naming

The period is named after Devon, a county in southwestern England, where Devonian outcrops are common. While the rock beds that define the start and end of the period are well identified, the exact dates are uncertain. According to the International Commission on Stratigraphy (Ogg, 2004), the Devonian extends from the end of the Silurian Period 416.0 ± 2.8 million years ago (Mya), to the beginning of the Carboniferous Period 359.2 ± 2.5 Mya (in North America, the beginning of the Mississippian subperiod of the Carboniferous) (ICS 2004). Part of the seafront of Torquay, south Devon, at high tide Devon is a large county in South West England, bordered by Cornwall to the west, and Dorset and Somerset to the east. ... For other uses, see strata (novel) and strata title. ... The International Commission on Stratigraphy concerns itself with stratigraphy on a global scale. ... The Silurian is a major division of the geologic timescale that extends from the end of the Ordovician period, about 443. ... Mega-annum, usually abbreviated as Ma, is a unit of time equal to one million years. ... President Bush- Deres gold in dem dere mines The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359. ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... “Mississippian” redirects here. ...


The Devonian has also erroneously been characterized as a "greenhouse age", due to sampling bias: most of the early Devonian-age discoveries came from the strata of western Europe and eastern North America, which at the time straddled the Equator as part of the supercontinent of Euramerica where fossil signatures of widespread reefs indicate tropical climates that were warm and moderately humid but in fact the climate in the Devonian differed greatly between epochs and geographic regions. For example, during the Early Devonian, arid conditions were prevalent through much of the world including Siberia, Australia, North America, and China, but Africa and South America had a warm temperate climate. In the Late Devonian, by contrast, arid conditions were less prevalent across the world and temperate climates were more common. In general, a sample is a part of the total, such as one individual or a set of individuals from a population (of people or things), a small piece or amount of something larger, a number of function values of a function, or part of a song. ... For other uses, see strata (novel) and strata title. ... A current understanding of Western Europe. ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... World map showing the equator in red In tourist areas, the equator is often marked on the sides of roads The equator marked as it crosses Ilhéu das Rolas, in São Tomé and Príncipe. ... For other uses, see Fossil (disambiguation). ... In the geological timescale, the Early Devonian epoch (from 416. ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... In the geological timescale, the Late Devonian epoch (from 385. ... For the usage in virology, see temperate (virology). ...


In nineteenth-century texts the Devonian has been called the "Old Red Age", after the red and brown terrestrial deposits known in the United Kingdom as the Old Red Sandstone in which early fossil discoveries were found. The Old Red Sandstone is a rock formation of considerable importance to early paleontology. ...


Devonian subdivisions

The Devonian is usually broken into Early, Middle, and Late subdivisions. The rocks corresponding to these epochs are referred to as belonging to the lower, middle, and upper parts of the Devonian System. The faunal stages from youngest to oldest are: Look up epoch in Wiktionary, the free dictionary. ... Faunal stages are a subdivision of geologic time used primarily by paleontologists who study fossils rather than by geologists who study rock formations. ...


Late (most recent)

The Famennian Age is one of two ages in the Late Devonian Period. ... The Frasnian Age is one of two ages in the Late Devonian Period. ...

Middle

The Givetian (also known as Erian, Senecan, Tioughniogan, Tioughnioga, Taghanic, Taghanican, Genesee, Geneseean) stage is the later stage of the Middle Devonian epoch. ... The Eifelian is one of two faunal stages in the Middle Devonian Period. ...

Early (oldest)

Helderberg Is a area in the Western Cape of South Africa. ... The Emsian is one of three faunal stages in the Early Devonian Period. ... The Pragian is one of three faunal stages in the Early Devonian epoch. ... The Lochkovian is one of three faunal stages in the Early Devonian epoch. ...

Devonian palaeogeography

The Devonian period was a time of great tectonic activity, as Laurasia and Gondwanaland drew closer together. The tectonic plates of the world were mapped in the second half of the 20th century. ... Laurasia was a supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic era. ... For other uses of Gondwana and Gondwanaland, see Gondwana (disambiguation). ...


The continent Euramerica (or Laurussia) was created in the early Devonian by the collision of Laurentia and Baltica, which rotated into the natural dry zone along the Tropic of Capricorn, which is formed as much in Paleozoic times as nowadays by the convergence of two great airmasses, the Hadley cell and the Ferrel cell. In these near-deserts, the Old Red Sandstone sedimentary beds formed, made red by the oxidized iron (hematite) characteristic of drought conditions. Euramerica (also known as Laurussia) was a minor supercontinent created in the Devonian by the collision of Laurentia and Baltica (Scandian Orogeny). ... This article or section does not adequately cite its references or sources. ... Baltica (green) Baltica is a Late Proterozoic-Early Palaeozoic continent that now includes the East European craton of northwestern Eurasia. ... World map showing the Tropic of Capricorn For the novel by Henry Miller, see Tropic of Capricorn (novel). ... The Hadley cell is a circulation pattern that dominates the tropical atmosphere, with rising motion near the equator, poleward flow 10-15 kilometers above the surface, descending motion in the subtropics, and equatorward flow near the surface. ... The Ferrel cell is usually shown between the Hadley and Polar cells, e. ... The Old Red Sandstone is a rock formation of considerable importance to early paleontology. ... Hematite, also spelled haematite, is the mineral form of Iron(III) oxide, (Fe2O3), one of several iron oxides. ...


Near the equator, Pangaea began to consolidate from the plates containing North America and Europe, further raising the northern Appalachian Mountains and forming the Caledonian Mountains in Great Britain and Scandinavia. World map showing the equator in red In tourist areas, the equator is often marked on the sides of roads The equator marked as it crosses Ilhéu das Rolas, in São Tomé and Príncipe. ... For other uses, see Pangaea (disambiguation). ... The tectonic plates of the world were mapped in the second half of the 20th century. ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... For other uses, see Europe (disambiguation). ... The Appalachian Mountains are a vast system of mountains in eastern North America. ... The Caledonian orogeny is a hypothetical series of events in geologic history explaining a group of highland formations that are very similar in composition, stratigraphy and fossils: the mountains and hills of northern England, Wales, Scotland, Ireland and west Norway. ... For other uses, see Scandinavia (disambiguation). ...


The west coast of Devonian North America, by contrast, was a passive margin with deep silty embayments, river deltas and estuaries, in today's Idaho and Nevada; an approaching volcanic island arc reached the steep slope of the continental shelf in Late Devonian times and began to uplift deep water deposits, a collision that was the prelude to the mountain-building episode of Mississippian times called the Antler orogeny [1]. Official language(s) English [1] Capital Boise Largest city Boise Largest metro area Boise metropolitan area Area  Ranked 14th  - Total 83,642 sq mi (216,632 km²)  - Width 305 miles (491 km)  - Length 479 miles (771 km)  - % water 0. ... This article is about the U.S. State of Nevada. ... An island arc is a type of archipelago formed by plate tectonics as one oceanic tectonic plate subducts under another and produces magma. ... The Antler orogeny is an orogeny that extensively deformed Paleozoic rocks of the Great Basin in Nevada during Late Devonian and Early Mississipian time. ...


The southern continents remained tied together in the supercontinent of Gondwana. The remainder of modern Eurasia lay in the Northern Hemisphere. Sea levels were high worldwide, and much of the land lay submerged under shallow seas, where tropical reef organisms lived. Animated, colour-coded map showing the various continents. ... In geology, a supercontinent is a land mass comprising more than one continental core, or craton. ... For other uses, see Reef (disambiguation). ...


The deep, enormous Panthalassa (the "universal ocean") covered the rest of the planet. Other minor oceans were Paleo-Tethys, Proto-Tethys, Rheic Ocean, and Ural Ocean (which was closed during the collision with Siberia and Baltica). Panthalassa (Greek for all seas) was the vast ocean that surrounded the supercontinent Pangaea during the late Paleozoic era and the early Mesozoic era. ... This article is about the astronomical term. ... The Paleo-Tethys Ocean was an ancient Paleozoic ocean. ... Proto-Tethys Ocean was an ancient ocean that existed from the latest Ediacaran to the Carboniferous. ... The Rheic Ocean was an ocean in the Paleozoic Era that existed between the continent of Baltica (northern Europe) and number of terranes broken up from Gondwana, including the future southern Europe. ... Ural Ocean was a small, ancient ocean that was situated between Siberia and Baltica. ... Siberia (Sometimes called Angara) is the craton located in the heart of the region of Siberia. ...


Devonian rocks are oil and gas producers in some areas.


Devonian biota

Fossil trilobite Ductina vietnamica from the Devonian of China
Fossil trilobite Ductina vietnamica from the Devonian of China
SEM image of a hederelloid from the Devonian of Michigan (largest tube diameter is 0.75 mm).
A Devonian spiriferid brachiopod from Ohio which served as a host substrate for a colony of hederelloids. The specimen is 5 cm wide.

Photograph of the fossil trilobite Ductina taken by Dlloyd. ... Photograph of the fossil trilobite Ductina taken by Dlloyd. ... Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... Hederellids are extinct colonial animals with calcitic tubular branching exoskeletons. ... Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Diversity About 4000 genera Subphyla and classes See Classification Brachiopods (from Latin bracchium, arm + New Latin -poda, foot) are a nearly extinct, small phylum of benthic invertebrates. ... Official language(s) English de facto Capital Columbus Largest city Columbus Largest metro area Greater Cleveland Area  Ranked 34th  - Total 44,825 sq mi (116,096 km²)  - Width 220 miles (355 km)  - Length 220 miles (355 km)  - % water 8. ... Hederellids are extinct colonial animals with calcitic tubular branching exoskeletons. ...

Marine biota

Sea levels in the Devonian were generally high. Marine faunas continued to be dominated by bryozoa, diverse and abundant brachiopods, the enigmatic hederelloids, and corals. Lily-like crinoids were abundant, and trilobites were still fairly common, but less diverse than in earlier periods due to the abundance of mobile swimming predators such as sharks and predatory bony fish (Osteichthyes) such as Dunkleosteus. The ostracoderms were joined in the mid-Devonian by the first jawed fishes and were declining in diversity and were being out competed by the jawed fish in both the sea and fresh water, also the great armored placoderms, as well as the first sharks and ray-finned fish. The first abundant species of shark, the Cladoselache, appeared in the oceans during the Devonian period. They became abundant and diverse. In the late Devonian the lobe-finned fish appeared, giving rise to the first tetrapods. Classes Stenolaemata Gymnolaemata Phylactolaemata Bryozoans are tiny colonial animals that generally build stony skeletons of calcium carbonate, superficially similar to coral. ... Classes Lingulata Paterinata (extinct) Craniforma Chileata (extinct) Obolellata (extinct) Kutorginata (extinct) Strophomenata (extinct) Rhynchonellata Brachiopods (from Latin bracchium, arm + New Latin -poda, foot) make up one of the major animal phyla, Brachiopoda. ... Hederellids are extinct colonial animals with calcitic tubular branching exoskeletons. ... Extant Subclasses and Orders Alcyonaria    Alcyonacea    Helioporacea Zoantharia    Antipatharia    Corallimorpharia    Scleractinia    Zoanthidea [1][2]  See Anthozoa for details For other uses, see Coral (disambiguation). ... Orders Articulata Cladida (extinct) Flexibilia (extinct) Camerada (extinct) Disparida (extinct) Crinoids, also known as sea lilies or feather-stars, are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). ... Orders Agnostida Redlichiida Corynexochida Lichida Nektaspida? Phacopida Proetida Asaphida Harpetida Ptychopariida Trilobites are extinct arthropods in the class Trilobita. ... Binomial name (Newberry, 1873) Dunkleosteus (formerly known as Dinichthys) was a large Placoderm (armoured prehistoric fish) that lived in the late Devonian period, about 360 – 415 million years ago. ... For the village on the Isle of Wight, see Freshwater, Isle of Wight. ... Orders Antiarchi † Arthrodira † Petalichthyda † Phyllolepida † Ptyctodontida † Rhenanida † The Placodermi are fish known from fossils dating to the Devonian period. ... Orders See text The Actinopterygii are the ray-finned fish. ... Cladoselache is a genus of extinct fish_like shark and is the oldest recognizable shark-like animal. ... Subclasses Coelacanthimorpha - Coelacanths Dipnoi - Lungfishes Tetrapoda Sarcopterygii is traditionally the class of lobe-finned fishes, consisting of lungfish and coelacanths. ... Classes Synapsida Sauropsida Amphibia A tetrapod (Greek tetrapoda, four-legged) is a vertebrate animal having four feet, legs or leglike appendages. ...


Reefs

A great barrier reef, now left high and dry in the Kimberley Basin of northwest Australia, once extended a thousand kilometers, fringing a Devonian continent. Reefs in general are built by various carbonate-secreting organisms that have the ability to erect wave-resistant frameworks close to sea level. The main contributors of the Devonian reefs were unlike modern reefs, which are constructed mainly by corals and calcareous algae. They were composed of calcareous algae and coral-like stromatoporoids, and tabulate and rugose corals, in that order of importance. The Kimberley is one of the nine regions of Western Australia, consisting of the local government areas of Broome, Derby-West Kimberley, Halls Creek and Wyndham-East Kimberley. ... Ball-and-stick model of the carbonate ion, CO32− For other meanings, see Carbonate (disambiguation) In chemistry, a carbonate is a salt or ester of carbonic acid. ... Algae have conventionally been regarded as simple plants within the study of botany. ... Families See text. ... Suborders Columnariina† Cystiphyllina† Streptelasmatina† The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permian seas. ...


Terrestrial biota

By the Devonian Period, life was well underway in its colonization of the land. The bacterial and algal mats were joined early in the period by primitive plants that created the first recognizable soils and harbored some arthropods like mites, scorpions and myriapods (although arthropods appeared on land much earlier than in the Early Devonian and the existence of fossils such as Climactichnites state that land arthropods may have appeared as early as the Cambrian period) Early Devonian plants did not have roots or leaves like the plants most common today, and many had no vascular tissue at all. They probably spread largely by vegetative growth, and did not grow much more than a few centimeters tall. Also the first possible fossils of insects appeared around 416 Ma in the Early Devonian. Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... For other uses, see Plant (disambiguation). ... Loess field in Germany Surface-water-gley developed in glacial till, Northern Ireland Soil is a complex mixture of materials, principally ground up rock and water. ... Look up mite in Wiktionary, the free dictionary. ... For other uses, see Scorpion (disambiguation). ... Classes Chilopoda - Centipedes Diplopoda - Millipedes Pauropoda - Pauropods Symphyla - Symphylans Four groups of arthropods—the centipedes, millipedes, pauropods, and symphylans—share a number of common features such as a similar body plan consisting of a head followed by an elongate trunk with many legs. ... In the geological timescale, the Early Devonian epoch (from 416. ... Climactichnites is a genus of trace fossil formed on sandy tidal flats in portions of Canada and northern United States around 510 Ma during late Cambrian time. ... For other uses, see Cambrian (disambiguation). ... Orders Subclass Apterygota Symphypleona - globular springtails Subclass Archaeognatha (jumping bristletails) Subclass Dicondylia Monura - extinct Thysanura (common bristletails) Subclass Pterygota Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Blattodea (cockroaches) Mantodea (mantids) Isoptera (termites) Zoraptera Grylloblattodea Dermaptera (earwigs) Plecoptera (stoneflies) Orthoptera (grasshoppers, crickets... Mega-annum, usually abbreviated as Ma, is a unit of time equal to one million years. ... In the geological timescale, the Early Devonian epoch (from 416. ...


By the Late Devonian, forests of small, primitive plants existed: lycophytes, sphenophytes, ferns, and progymnosperms had evolved. Most of these plants have true roots and leaves, and many were quite tall. The tree-like ancestral fern Archaeopteris and the giant cladoxylopsid trees grew as a large tree with true wood. These are the oldest known trees of the world's first forests. Prototaxites was the fruiting body of an enormous fungus that stood more than 8 meter tall. By the end of the Devonian, the first seed-forming plants had appeared. This rapid appearance of so many plant groups and growth forms has been called the "Devonian Explosion". The primitive arthropods co-evolved with this diversified terrestrial vegetation structure. The evolving co-dependence of insects and seed-plants that characterizes a recognizably modern world had its genesis in the late Devonian. The development of soils and plant root systems probably led to changes in the speed and pattern of erosion and sediment deposition. Classes Lycopodiopsida - clubmosses Selaginellopsida - spikemosses Isoetopsida - quillworts The division Lycopodiophyta is a tracheophyte subdivision of the Kingdom Plantae that includes some of the most primitive of extant (living) vascular plants. ... This article is about the group of pteridophyte plants. ... This article is about evolution in biology. ... Archaeopteris is an extinct genus of tree-like ferns that many scientists believe to be the first tree. ... The cladoxylopsids are a group of plants known only as fossils that are thought to be ancestors of ferns and horsetails. ... For other uses, see Wood (disambiguation). ... Prototaxites is the name given to what seems to be a genus of large terrestrial fungus, with fossils dating from the Devonian and Silurian periods (approximately 420 to 350 million years ago) Prototaxites had large trunks up to 1 m (3 ft. ... For morphological image processing operations, see Erosion (morphology). ...


The earliest known trees, from the genus Wattieza, appeared in the Late Devonian around 380 Ma.[2] Wattieza was a group of extinct, prehistoric fern-like plants. ... In the geological timescale, the Late Devonian epoch (from 385. ... Mega-annum, usually abbreviated as Ma, is a unit of time equal to one million years. ...


The 'greening' of the continents acted as a carbon dioxide sink, and atmospheric levels of this greenhouse gas may have dropped. This may have cooled the climate and led to a massive extinction event. see Late Devonian extinction. Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... A carbon dioxide (CO2) sink is a carbon reservoir that is increasing in size, and is the opposite of a carbon dioxide source. The main natural sinks are (1) the oceans and (2) plants and other organisms that use photosynthesis to remove carbon from the atmosphere by incorporating it into... Air redirects here. ... Top: Increasing atmospheric CO2 levels as measured in the atmosphere and ice cores. ... An extinction event (also known as: mass extinction; extinction-level event, ELE) occurs when there is a sharp decrease in the number of species in a relatively short period of time. ... Comparison of the three episodes of extinction in the Late Devonian (Late D) to other mass extinction events in Earths history. ...


Also in the Devonian, both vertebrates and arthropods were solidly established on the land. This article does not cite any references or sources. ...


Late Devonian extinction

A major extinction occurred at the beginning of the last phase of the Devonian period, the Famennian faunal stage, (the Frasnian-Famennian boundary), about 364 million years ago, when all the fossil agnathan fishes, save for the psammosteid heterostracans, suddenly disappeared. A second strong pulse closed the Devonian period. The Late Devonian extinction was one of five major extinction events in the history of the Earth's biota, more drastic than the familiar extinction event that closed the Cretaceous. Comparison of the three episodes of extinction in the Late Devonian (Late D) to other mass extinction events in Earths history. ... There are very few or no other articles that link to this one. ... Family Anglaspis Palaeodus Cyathaspidae Heterostraci (Heterostracans) are an extinct marine taxon of vertebrate. ...


The Devonian extinction crisis primarily affected the marine community, and selectively affected shallow warm-water organisms rather than cool-water organisms. The most important group to be affected by this extinction event were the reef-builders of the great Devonian reef-systems .


Amongst the severely affected marine groups were the brachiopods, trilobites, ammonites, conodonts, and acritarchs, as well as jawless fish, and all placoderms. Freshwater species, including our tetrapod ancestors, were less affected. Diversity About 4000 genera Subphyla and classes See Classification Brachiopods (from Latin bracchium, arm + New Latin -poda, foot) are a nearly extinct, small phylum of benthic invertebrates. ... For other uses, see Ammonite (disambiguation). ... Conodonts are extinct worm-like forms with distinctive conical or multi-denticulate teeth made of apatite (calcium phosphate). ... Acritarchs are small organic structures found as fossils. ...


Reasons for the late Devonian extinctions are still speculative.


Notes

  1. ^ See Tiktaalik.

Binomial name Daeschler, Shubin & Jenkins, 2006 Tiktaalik (IPA pronunciation: ) is a genus of extinct sarcopterygian (lobe-finned) fishes from the late Devonian period, with many features akin to those of tetrapods (four-legged animals) [1]. It is an example from several lines of ancient sarcopterygian fish developing adaptations to oxygen...

References

  • Ogg, Jim; June, 2004, Overview of Global Boundary Stratotype Sections and Points (GSSP's) http://www.stratigraphy.org/gssp.htm Accessed April 30, 2006.

See also

The geologic time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth. ... Binomial name Phacops rana Phacops rana is a species of trilobite from the middle Devonian period. ... List of fossil sites: // ^ http://www. ...

External links

Wikimedia Commons has media related to:
Devonian
Devonian period
Lower/Early Devonian Middle Devonian Upper/Late Devonian
Lochkovian | Pragian
Emsian
Eifelian | Givetian Frasnian | Famennian
Paleozoic era
Cambrian Ordovician Silurian Devonian Carboniferous Permian

  Results from FactBites:
 
Devonian - Wikipedia, the free encyclopedia (1117 words)
The Devonian is a geologic period of the Paleozoic era.
The paleogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, and the early formation of the small supercontinent of Euramerica in the middle.
The continent Euramerica (or Laurussia) was created in the early Devonian by the collision of Laurentia and Baltica, which rotated into the natural dry zone along the Tropic of Capricorn, which is formed as much in Paleozoic times as nowadays by the convergence of two great airmasses, the Hadley cell and the Ferrel cell.
USGS Professional Paper 1151-H: The Geology of Kentucky: Devonian System (2402 words)
Westward, in the Illinois basin, the subsurface Devonian section thickens to 1,800 ft; the upper 470 ft is shale, and the remainder is limestone and dolomite (data extrapolated from Collinson and Atherton, 1975, p.
The erosion that preceded the Middle Devonian accumulation of carbonate rocks took place during an interval of mild tectonic warping along structures such as the incipient Cincinnati arch and the tighter folds that parallel or are normal to the present strike of the Appalachian Valley and Ridge province and the Pine Mountain thrust fault.
Devonian chert and clay (Dcc).-Weathered Chattanooga Shale and chert and clay residue of the underlying Middle and Lower Devonian limestone is exposed in faulted localities in Marshall and Lyon Counties in western Kentucky (area 5, fig.
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