from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of or belonging to the geologic time, system of rocks, or sedimentary deposits of the fourth period of the Paleozoic Era, characterized by the development of lobe-finned fishes, the appearance of amphibians and insects, and the first forests. See Table at geologic time.
- n. The Devonian Period or its system of deposits.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. of a geologic period within the Paleozoic era; comprises lower, middle and upper epochs from about 415 to 360 million years ago
- adj. Of or pertaining to the English region of Devon.
- n. A native or inhabitant of the English region of Devon.
- proper n. the Devonian period
from the GNU version of the Collaborative International Dictionary of English
- adj. Of or pertaining to Devon or Devonshire in England.
- n. The Devonian age or formation.
from The Century Dictionary and Cyclopedia
- Of or pertaining to Devonshire in England.
- The term was applied specifically, in geology, by Murchison to a great part of the Paleozoic strata of North and South Devon, and used by him as synonymous with Old Red Sandstone, for which term he substituted it, “because the strata of that age in Devonshire—lithologically very unlike the old red sandstone of Scotland, Hereford, and the South Welsh counties—contain a much more copious and rich fossil fauna, and were shown to occupy the same intermediate position between the Silurian and Carboniferous rocks.” Later geologists, however, do not use the terms as identical, the conditions under which the strata were deposited being very different.
- This term was first applied in geology by Sedgwick and Murchison to a series of rocks in North and South Devon and Cornwall in which fossils had been found which were recognized by Lonsdale as intermediate in character between Silurian and Carboniferous. The lower and upper limits of the formation were not defined in Britain, but were more precisely determined by the same geologists in the Rhineland. So uncertain, however, were the bounds assigned to the base of the formation that more recent study in various countries has added to the lower part of this system considerable beds that had before been assigned to the Silurian system. Strictly applied, the term Devonian implies the rocks bearing the marine faunas of that time and is contrasted with the Old Red Sandstone, which is a formation sometimes different lithologically and which represents the lake, lagoon, or delta deposits of the same age.
- n. A native or inhabitant of Devonshire.
- n. In geology, the Devonian series.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. from 405 million to 345 million years ago; preponderance of fishes and appearance of amphibians and ammonites
Now, this oil is found in what they call the Devonian limestone, and it is our first production from Devonian.
The bet was placed thousands of miles away in south-eastern United States, on a sandstone rock formation called Devonian shale.
Certain ancient strata, known as the Devonian black shale, occupying the Ohio valley and the neighbouring parts of North America to the east and north of that basin, appear to be accumulations which were made beneath an ancient Sargassum sea.
The other stowaway, whom I will call the Devonian -- it was noticeable that neither of them told his name -- had both been brought up and seen the world in a much smaller way.
The researchers suggest that low global oxygen levels during this period, known as the Devonian, may explain the evolution of air-gulping characteristics.
The thick Thunderhead Sandstone (Upper Precambrian Great Smoky Group) in the Great Smoky Mountains along the Tennessee/North Carolina border was deformed and regionally metamorphosed during formation of the Appalachian Highlands, beginning in the so-called Devonian (that is, early in the Flood year).12-14 With increasing temperatures and pressures from northwest to southeast, the regional metamorphism produced in these sandstone layers a series of chemically and mineralogically distinct zones of schists and gneisses.15 These zones are named according to the first appearance of the distinctive metamorphic minerals which characterize them as the intensity of the metamorphism increased laterally—the biotite, garnet, staurolite, and kyanite zones.
According to Mr H.B. Woodward (_History of the Geological Society of London_, 1907, p. 107) "Lonsdale's 'important and original suggestion of the existence of an intermediary type of Palæozoic fossils, since called Devonian,' led to a change which was then
Any year with a description of a Devonian anomalocarid is worth remembering.
* In order from oldest to youngest, the extinction events considered by biologists and paleontologists to be the most severe in the earth's history are the Ordovician – Silurian extinction event, the Late Devonian extinction, the Permian – Triassic extinction event, the Triassic – Jurassic extinction event, the Cretaceous – Tertiary extinction event, and the Quaternary-Holocene extinction event (currently underway).
(21 May 2010) * In order from oldest to youngest, the extinction events considered by biologists and paleontologists to be the most severe in the earth's history are the Ordovician – Silurian extinction event, the Late Devonian extinction, the Permian – Triassic extinction event, the Triassic – Jurassic extinction event, the Cretaceous – Tertiary extinction event, and the Quaternary-Holocene extinction event (currently underway).