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The Silurian (/ s ɪ ˈ lj ʊər i. ən, s aɪ-/ sih-LURE-ee-ən, sy-) [8] [9] [10] is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.1 million years ago , to the beginning of the Devonian Period, 419.62 Mya. [11] The Silurian is the third and shortest period of the Paleozoic Era, and the ...
The Silurian hypothesis is a thought experiment, [1] which assesses modern science's ability to detect evidence of a prior advanced civilization, perhaps several million years ago. The most probable clues for such a civilization could be carbon , radioactive elements or temperature variation.
Reference is occasionally made to this period of Celtic history by the use of terms such as "Silurian". The poet Henry Vaughan called himself a "Silurist", by virtue of his roots in South Wales . The geological period Silurian was first described by Roderick Murchison in rocks located in the original lands of the Silures, hence the name.
538.8 Ma – 251.9 Ma and contains the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods. With only a handful of species surviving today, the Nautiloids flourished during the early Paleozoic era, from the Late Cambrian, where they constituted the main predatory animals. [71]
Rocks representing a given chronostratigraphic unit are that chronostratigraphic unit, and the time they were laid down in is the geochronologic unit, e.g., the rocks that represent the Silurian System are the Silurian System and they were deposited during the Silurian Period. This definition means the numeric age of a geochronologic unit can ...
The Silurian-Devonian Terrestrial Revolution, also known as the Devonian Plant Explosion (DePE) [1] and the Devonian explosion, was a period of rapid colonization, diversification and radiation of land plants and fungi on dry lands that occurred 428 to 359 million years ago (Mya) during the Silurian and Devonian periods, [2] [3] [4] with the ...
The Wenlock Epoch (sometimes referred to as the Wenlockian) is the second epoch of the Silurian. It is preceded by the Llandovery Epoch and followed by the Ludlow Epoch. Radiometric dates constrain the Wenlockian between 432.9 and 426.7 million years ago. [5]
Silurian (443–419 Ma): Many evolutionary milestones occurred during this period, including the appearance of armoured jawless fish, jawed fish, spiny sharks and ray-finned fish. While it is traditional to refer to the Devonian as the age of fishes, recent findings have shown the Silurian was also a period of considerable diversification.