Crossword clues for devonian
The Collaborative International Dictionary
Devonian \De*vo"ni*an\, n. The Devonian age or formation.
Devonian \De*vo"ni*an\, a. (Geol.) Of or pertaining to Devon or Devonshire in England; as, the Devonian rocks, period, or system.
Devonian age (Geol.), the age next older than the Carboniferous and later than the Silurian; -- called also the Age of fishes. The various strata of this age compose the Devonian formation or system, and include the old red sandstone of Great Britain. They contain, besides plants and numerous invertebrates, the bony portions of many large and remarkable fishes of extinct groups. See the Diagram under Geology.
Douglas Harper's Etymology Dictionary
1837, as a geological era, from the English county of Devon, where the Old Red Sandstone formations of that age are prominent, + -ian.
Wikipedia
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about Mya (million years ago), to the beginning of the Carboniferous Period, about . It is named after Devon, England, where rocks from this period were first studied. The Devonian period experienced the first significant adaptive radiation of terrestrial life. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the "Age of Fish". The first ray-finned and lobe-finned bony fish appeared, while the placoderms began dominating almost every known aquatic environment.
The ancestors of all tetrapods began adapting to walking on land, their strong pectoral and pelvic fins gradually evolving into legs. In the oceans, primitive sharks became more numerous than in the Silurian and the late Ordovician. The first ammonite mollusks appeared. Trilobites, the mollusk-like brachiopods and the great coral reefs, were still common. The Late Devonian extinction which started about 375 million years ago severely affected marine life, killing off all placoderms, and all trilobites, save for a few species of the order Proetida.
The paleogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, and the early formation of the small continent of Euramerica in between.
Devonian is a geologic period and system of the Paleozoic Era. This may also refer to:
Usage examples of "devonian".
Empty platforms rushed past, their names in title: Cambrian, Ordovician, Silurian, Devonian, Permian, Triassic, Jurassic.
I need give only one instance, namely, the manner in which the fossils of the Devonian system, when this system was first discovered, were at once recognised by palaeontologists as intermediate in character between those of the overlying carboniferous, and underlying Silurian system.
The long-ago seas of the Carboniferous and Devonian swarmed with tiny plankton that wrapped themselves inside tiny protective shells.
This, as it belongs to the Upper Devonian or Lower Carboniferous, determines a lower limit for the age of the sandstone formation.
I hope the Professor, wherever he is—in the Upper Devonian or Jurassic or even the Lower Cretacious period—knows of his accidental triumph.
I hope the Professor, wherever he isin the Upper Devonian or Jurassic or even the Lower Cretacious periodknows of his accidental triumph.
Maybe there was a little temblor deep down in the Devonian, or maybe the open air had a corrosive effect on the exposed support timbers.
Amid the muddied ash and clay, the world was taking on a look it had not had since the Devonian age some four hundred million years before, when the first land plants of all&mdash.
Amid the muddied ash and clay, the world was taking on a look it had not had since the Devonian age some four hundred million years before, when the first land plants of all—.
The cliffs are early Triassic sandstone laid atop Permian coal measures, under which lie the granites, shales and limestones of Devonian and Silurian times.
It would be many months before the team was able to definitively identify the fish at Happy Fish as a coelacanth, a lobe-finned fish that first emerged in the Devonian Period of the Paleozoic Era, some 400 million years ago, and became extinct not long after the rocks of Bahariya were laid down.
From 380 to 362 million years ago, during what's now labeled the Devonian period of the Paleozoic Era, mass extinctions removed about 70 percent of life in the ocean.
They had even attempted to find coal under strata which are usually below it, such as the Devonian red sandstone, but without result.