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Introduction

Map of Earth as it appeared 400 million years ago during the Early Devonian, Emsian stage

The Devonian (/dəˈvni.ən, dɛ-/ də-VOH-nee-ən, deh-) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at 419.2 million years ago (Ma), to the beginning of the succeeding Carboniferous period at 358.9 Ma. It is the fourth period of both the Paleozoic and the Phanerozoic. It is named after Devon, South West England, where rocks from this period were first studied.

The first significant evolutionary radiation of life on land occurred during the Devonian, as free-sporing land plants (pteridophytes) began to spread across dry land, forming extensive coal forests which covered the continents. By the middle of the Devonian, several groups of vascular plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants (pteridospermatophytes) appeared. This rapid evolution and colonization process, which had begun during the Silurian, is known as the Silurian-Devonian Terrestrial Revolution. The earliest land animals, predominantly arthropods such as myriapods, arachnids and hexapods, also became well-established early in this period, after beginning their colonization of land at least from the Ordovician period. (Full article...)

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Selected article on the Devonian world and its legacies

An unidentified Devonian brachiopod from Morocco.
An unidentified Devonian brachiopod from Morocco.
Brachiopods are marine animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalvemolluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major groups are recognized, articulate and inarticulate. Articulate brachiopods have toothed hinges and simple opening and closing muscles, while inarticulate brachiopods have untoothed hinges and a more complex system of muscles used to keep the two halves aligned. In a typical brachiopod a stalk-like pedicle projects from an opening in one of the valves, known as the pedicle valve, attaching the animal to the seabed.

Lineages of brachiopods that have both fossil and extant taxa appeared in the early Cambrian, Ordovician, and Carboniferous periods, respectively. Other lineages have arisen and then become extinct, sometimes during severe mass extinctions. At their peak in the Paleozoic era, the brachiopods were among the most abundant filter-feeders and reef-builders, and occupied other ecological niches, including swimming in the jet-propulsion style of scallops. However, after the Permian–Triassic extinction event, brachiopods recovered only a third of their former diversity. It was often thought that brachiopods were in decline after the Permian–Triassic extinction, and were out-competed by bivalves. However, a study in 1980 found both brachiopod and bivalve species increased from the Paleozoic to modern times, but bivalves increased faster; after the Permian–Triassic extinction, brachiopods for the first time became less diverse than bivalves. (see more...)

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Restoration of Hastocularis argus.
Restoration of Hastocularis argus.

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Life restoration of Pandericthys.

Life restoration of Panderichthys.
Photo credit: Dmitry Bogdanov

Selected article on the Devonian in human science, culture and economics

Geologic map of the US state of Georgia.
Geologic map of the US state of Georgia.
The geologic map of Georgia (a state within the United States) is a special-purpose map made to show geological features. Rock units or geologic strata are shown by colors or symbols to indicate where they are exposed at the surface. Structural features such as faults and shear zones are also shown. Since the first national geological map, in 1809, there have been numerous maps which included the geology of Georgia. The first Georgia specific geologic map was created in 1825. The most recent state-produced geologic map of Georgia, by the Georgia Department of Natural Resources is 1:500,000 scale, and was created in 1976 by the department's Georgia Geological Survey. It was generated from a base map produced by the United States Geological Survey. The state geologist and Director of the Geological Survey of Georgia was Sam M. Pickering, Jr. Since 1976, several geological maps of Georgia, featuring the state's five distinct geologic regions, have been produced by the federal government. (see more...)

Geochronology

Epochs - Early Devonian - Middle Devonian - Late Devonian
Ages - Lochkovian - Pragian - Emsian - Eifelian - Givetian - Frasnian - Famennian
Events - Alice Springs Orogeny - Caledonian orogeny - Acadian orogeny - Karoo Ice Age

Landmasses - Baltica - Laurentia - Euramerica - Gondwana
Bodies of water Ural Ocean - Panthalassa Paleo-Tethys - Proto-Tethys - Rheic Ocean
Animals - Ammonoids - Brachiopods - Bryozoans - Corals - Crinoids - Hederelloids - Insects - Microconchids - Ostracoderms - Placoderms - Sharks - Tetrapods - Trilobites
Fungi - Prototaxites
Plants - Ferns - Horsetails - Lycophytes - Progymnosperms

Fossil sites - Grenfell fossil site
Stratigraphic units - Columbus Limestone - Gogo Formation - Hunsrück Slate - Jeffersonville Limestone - Keyser Formation - Mahantango Formation - Marcellus Formation - New Albany Shale - Old Port Formation - Old Red Sandstone - Rhynie chert

History - The Great Devonian Controversy
Researchers - Henry De la Beche - Roderick Murchison - Neil Shubin
Culture - Animal Armageddon - List of creatures in the Walking with... series - Miracle Planet - Sea Monsters - Walking With Monsters

Quality Content

Featured Devonian articles - None
Good Devonian articles - Chitinozoan - Fish - Marcellus Formation - Ornatifilum - Schinderhannes - Tiktaalik

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Current Devonian FACs - none currently

Associated Wikimedia

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