User:Abyssal/Portal:Cambrian

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The Cambrian Portal

Introduction

The Cambrian ( /ˈkæmbri.ən, ˈkeɪm-/ KAM-bree-ən, KAYM-) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 485.4 Ma.

Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new convergent plate boundaries and continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. (Full article...)

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A fungus (/ˈfʌŋɡəs/; plural: fungi) is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants and animals. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants and some protists, which contain cellulose. These and other differences show that the fungi form a single group of related organisms, named the Eumycota. The discipline of biology devoted to the study of fungi is known as mycology. Genetic studies have shown that fungi are more closely related to animals than to plants.

Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil, on dead matter, and as symbionts of plants, animals, or other fungi. They may become noticeable when fruiting, either as mushrooms or molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange. However, little is known of the true biodiversity of Kingdom Fungi, which has been estimated at 1.5 million to 5 million species. Phylogenetic studies published in the last decade have helped reshape the classification of Kingdom Fungi, which is divided into one subkingdom, seven phyla, and ten subphyla. A group of all the fungi present in a particular area or geographic region is known as mycobiota. (see more...)

Did you know...

... that Kendallina, a genus of trilobite, lived in North America during the Upper Cambrian?
... that species of the Cambrian bivalve Tuarangia lived near the continents of Baltica and East Gondwana?
... that a revolution in burrowing marks the base of the Cambrian period, and is followed by the Cambrian explosion of animal diversity?
... that the discovery of 189 fossils of the mid-Cambrian Odontogriphus thrust it into the centre of a heated debate about the evolution of molluscs, annelids and brachiopods?
... that August 2009 heralded the 100th anniversary of the discovery of the main Burgess Shale locality?

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Nectocaris pteryx after the reconstruction in Smith & Caron 2010.
Photo credit: User:Citron

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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...)