542–488.3 million years ago
Mean atmospheric O2 content over period duration ca. 12.5 Vol %
(63 % of modern level)
Mean atmospheric CO2 content over period duration ca. 4500 ppm
(16 times pre-industrial level)
Mean surface temperature over period duration ca. 21 °C
(7 °C above modern level)
Sea level (above present day) Rising steadily from 30m to 90m
The Cambrian is the first geological period of the Paleozoic Era, lasting from to Mya (ICS, 2004, chart); it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's Cambrian rocks are best exposed. It should not be confused with the Cambrian supereon, the current supereon of the planet.
The Cambrian is unique in its unusually high proportion of lagerstätten. These are sites of exceptional preservation, where 'soft' parts of organisms are preserved as well as their more resistant shells. This means that our understanding of the Cambrian biology surpasses that of some later periods.
The Cambrian Period marked a profound change in life on Earth; prior to the Cambrian era, life was on the whole was small and simple. Complex organisms gradually became more common in the millions of years immediately preceding the Cambrian, but it was not until this period that mineralised – hence readily fossilised – organisms became common. This diversification of lifeforms was relatively rapid, and is termed the Cambrian explosion. This vast increase in diverse forms of life produced the first representatives of many modern phyla, representing the evolutionary stems of modern groups of species. While life prospered in the oceans, the land was barren – with nothing more than a microbial 'crud' known as soil crust covering the land. Apart from some tentative evidence suggesting that a few animals foundered around on land, most of the continents resembled deserts spanning from horizon to horizon. Shallow seas flanked the margins of several continents created during the breakup of the supercontinent Pannotia. The seas were relatively warm, and polar ice was absent for much of the period.
The United States Federal Geographic Data Committee uses a "barred capital C" character similar to the capital letter Ukrainian Ye ‹Є› to represent the Cambrian Period. The proper glyph is a proposed addition to the Unicode standard at code point A792.
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cambrian — CAMBRIÁN, Ă, cambrieni, e, s.n., adj. 1. Prima perioadă a erei paleozoice (în care au apărut vieţuitoarele). 2. adj. Care se referă la cambrian (1). [pr.: bri an] – Din fr. cambrien. Trimis de valeriu, 11.02.2003. Sursa: DEX 98 cambrián adj … Dicționar Român
Cambrian — [kam′brēən] adj. 1. of Cambria; Welsh 2. designating or of the first geologic period of the Paleozoic Era, characterized by the development of warm, shallow seas and the first hard shelled marine animals, esp. trilobites and brachiopods n. a… … English World dictionary
Cambrian — Cam bri*an, n. 1. A native of Cambria or Wales. [1913 Webster] 2. (Geol.) The Cambrian formation. [1913 Webster] … The Collaborative International Dictionary of English
Cambrian — Cam bri*an, a. 1. (Geog.) Of or pertaining to Cambria or Wales. [1913 Webster] 2. (Geol.) Of or pertaining to the lowest subdivision of the rocks of the Silurian or Molluscan age; sometimes described as inferior to the Silurian. It is named from… … The Collaborative International Dictionary of English
Cambrian — 1650s, from or of Wales or the Welsh, from Cambria, variant of Cumbria, Latinized derivation of Cymry, the name of the Welsh for themselves, from O.Celt. Combroges compatriots. Geological sense (of rocks first studied in Wales and Cumberland) is… … Etymology dictionary
Cambrian — ► ADJECTIVE 1) Welsh. 2) Geology relating to the first period in the Palaeozoic era (between the Precambrian aeon and the Ordovician period, about 570 to 510 million years ago). ORIGIN from Latin Cambria, from Welsh Cymru Wales … English terms dictionary
Cambrian — Primordial Pri*mor di*al, a. [L. primordialis, from primordium the first beginning; primus first + ordiri to begin a web, to begin: cf. F. primordial.] 1. First in order; primary; original; of earliest origin; as, primordial condition. The… … The Collaborative International Dictionary of English
Cambrian — adjective Etymology: Medieval Latin Cambria Wales, from Middle Welsh Cymry Wales, Welshmen Date: 1604 1. welsh 2. of, relating to, or being the earliest geologic period of the Paleozoic era or the corresponding system of rocks marked by fossils… … New Collegiate Dictionary
Cambrian — /kam bree euhn/, adj. 1. Geol. noting or pertaining to a period of the Paleozoic Era, occurring from 570 million to 500 million years ago, when algae and marine invertebrates were the predominant form of life. See table under geologic time. 2. of … Universalium
Cambrian — 1. adjective /ˈkæm.bɹiən/ a) of a geologic period within the Paleozoic era; comprises lower, middle and Furongian epochs from about 542 to 490 million years ago b) of, or relating to Wales 2 … Wiktionary