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Universalium. 2010.
Pennsylvanian — This article is about the geologic subperiod. For passenger train, see Pennsylvanian (Amtrak). System Subsystem/ Series Stage Age (Ma) Permian Cisuralian Asselian younger … Wikipedia
Mississippian Subperiod — ▪ geochronology first major subdivision of the Carboniferous Period, lasting from 359.2 to 318.1 million years ago. The Mississippian is characterized by shallow water limestone deposits occupying the interiors of continents, especially in… … Universalium
Carboniferous Period — Interval of geologic time 354–290 million years ago, marked by great changes in world geography. All the landmasses drew closer together as a result of tectonic plate movements. The supercontinent Gondwana occupied much of the Southern Hemisphere … Universalium
amphibian — /am fib ee euhn/, n. 1. any cold blooded vertebrate of the class Amphibia, comprising frogs and toads, newts and salamanders, and caecilians, the larvae being typically aquatic, breathing by gills, and the adults being typically semiterrestrial,… … Universalium
Carboniferous — For the album by Zu see Carboniferous (album). Carboniferous Period 359.2–299 million years ago … Wikipedia
Bashkirian Stage — ▪ geology first of four internationally defined stages of the Pennsylvanian Subsystem (Pennsylvanian Subperiod), Carboniferous System (Carboniferous Period), encompassing all rocks deposited during the Bashkirian Age (318.1 to 311.7 million … Universalium
geochronology — geochronologic /jee oh kron l oj ik/, geochronological, adj. geochronologist, n. /jee oh kreuh nol euh jee/, n. the chronology of the earth, as based on both absolute and relative methods of age determination. [1890 95; GEO + CHRONOLOGY] * * *… … Universalium
agnathan — /ag neuh theuhn/, n. 1. any member of the vertebrate class Agnatha. adj. 2. agnathous. [AGNATH(A) + AN] * * * ▪ fish Introduction any member of the group of primitive, jawless fishes (fish) that includes the lampreys (lamprey) (order… … Universalium
coal — coalless, adj. /kohl/, n. 1. a black or dark brown combustible mineral substance consisting of carbonized vegetable matter, used as a fuel. Cf. anthracite, bituminous coal, lignite. 2. a piece of glowing, charred, or burned wood or other… … Universalium
Serpukhovian Stage — ▪ geology third of three internationally defined stages of the Mississippian Subsystem (Mississippian Subperiod), Carboniferous System (Carboniferous Period), encompassing all rocks deposited during the Serpukhovian Age (326.4 to 318.1… … Universalium
