Devonian period


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Related to Devonian period: Silurian period, Carboniferous period, Mississippian Period, Permian period

See also: Geologic Timescale (table)Geologic Timescale
Era Period Epoch Approximate duration
(millions of years)
Approximate number of years ago
(millions of years)

Cenozoic Quaternary Holocene 10,000 years ago to the present  
Pleistocene 2 .
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Devonian period

(dĭvō`nēən), fourth period of the Paleozoic eraPaleozoic era
, a major division (era) of geologic time (see Geologic Timescale, table) occurring between 570 to 240 million years ago. It is subdivided into six periods, the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian (see each listed individually).
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 of geologic time between 408 and 360 million years ago (see Geologic TimescaleGeologic Timescale
Era Period Epoch Approximate duration
(millions of years)
Approximate number of years ago
(millions of years)

Cenozoic Quaternary Holocene 10,000 years ago to the present  
Pleistocene 2 .
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, table). It was named (1838) by the geologists Sir Roderick Impey MurchisonMurchison, Sir Roderick Impey
, 1792–1871, British geologist. He served in the Napoleonic Wars but after the peace turned his attention to science. In the 1830s he undertook the investigation of previously undifferentiated rock strata in Wales and England; as a result of
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 and Adam SedgwickSedgwick, Adam,
1785–1873, English geologist. He was a professor at Cambridge from 1818. His most important work was a study, made with R. I. Murchison, of the rock formation of Devonshire, which they named the Devonian system. Sedgwick also introduced the term Cambrian.
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 for Devonshire, England, where they first investigated rocks formed during the period. The Devonian period was a time of great tectonic activity, as Laurasia and Gondwanaland drew closer together. Pangaea began to consolidate the plates containing North America and Europe (see plate tectonicsplate tectonics,
theory that unifies many of the features and characteristics of continental drift and seafloor spreading into a coherent model and has revolutionized geologists' understanding of continents, ocean basins, mountains, and earth history.
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), further raising the northern Appalachian Mountains and forming the Caledonides in Britain and Scandinavia. For much of the Devonian, large areas of North America and Europe, and smaller parts of Africa, South America, and Australia were covered by seas, which withdrew during the Upper Devonian. The Cordilleran area of North America was submerged, depositing from 4,000 to 6,000 ft (1,200–1,800 m) of limestone and shale in Nevada and 2,400 ft (730 m) of quartzites and limestones in Utah. The Devonian period in Europe was marked by considerable volcanic activity and the deposition of two great rock systems: the marine formation of Devonshire, the Rhine valley, and Russia; and the Old Red SandstoneOld Red Sandstone,
series of red and brown sandstones, conglomerates, and shales deposited in Wales and Scotland and in England near the Welsh and Scottish borders in the Devonian period of geologic time.
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. The climate was relatively warm everywhere on the earth. The most notable Devonian animals were the jawed and bony fishes, which appeared in great numbers toward the close of the period. Conspicuous types were sharks, armored fishes, lungfishes, and ganoid fishes. Common invertebrates of the Devonian were crinoids, starfishes, sponges, and early ammonites; trilobites and graptolites became scarcer. An unusual surge of coral reef growth also occurred and corals were never again as prolific. Of land animals, the chief vestige is the footprint of a primitive salamanderlike amphibian in the Upper Devonian of Pennsylvania. Trees made their first appearance; the Devonian plants were the earliest to be extensively preserved as fossils, but their high degree of development suggests that more primitive forms existed earlier.
References in periodicals archive ?
The Devonian Period (415 to 360 million years ago) is often described as the Age of Fishes because of the rich variety of aquatic forms that populated the ancient seas, lagoons and streams.
The Devonian Period is considered especially important by scientists as it was when animals and plants began to colonise dry land for the first time.
Tour the Ancient Seas lets users explore the rough waters of the Devonian period seas to learn about Pucampella's ancient colleagues.
At that time, the end of the Devonian period, some new styles of creatures appeared on the scene.
Well-preserved fossils of extinct armoured fish belonging to in the early Devonian Period around 400 to 410 million years ago suggest that the activity of sex wasn't just "spawning in water, but sex that was fun", according to project leader John Long.
Mr Tarrant, an artist and amateur geologist, is an expert on the Devonian period.
The extinct plant Archaeopteris lived during the late Devonian period, when amphibians were just beginning to crawl onto land.
In the late Devonian period, some 365 million years ago, fish-like creatures began venturing onto land from shallow waters using eight-fingered limbs.
According to textbook paleontology, insects and other invertebrates retained unrivaled control of the continents until the late Devonian period, when amphibious vertebrates first hauled themselves out of the swamps (SN: 7/30/94, p.
The Devonian Period, which spanned from 416 to 359 million years ago, is also known as the Age of Fishes for the broad array of species present in Earth's aquatic environments.
These animals, which lived during the Devonian period about 365 million years ago, were among the earliest vertebrates (backboned animals) with fore- and hindlimbs rather than paired fins.