Crossword clues for ordovician
The Collaborative International Dictionary
Ordovician \Or`do*vi"cian\, a. [From L. Ordovices, a Celtic people in Wales.] (Geol.) Of or pertaining to a division of the Silurian formation, corresponding in general to the Lower Silurian of most authors, exclusive of the Cambrian. -- n. The Ordovician formation.
Douglas Harper's Etymology Dictionary
geological period following the Cambrian and preceding the Silurian, 1879, coined by English geologist Charles Lapworth (1842-1920) from Latin Ordovices, name of an ancient British tribe in North Wales. The period so called because rocks from it first were studied extensively in the region around Bala in North Wales. The tribe's name is Celtic, literally "those who fight with hammers," from Celtic base *ordo "hammer" + PIE *wik- "to fight, conquer" (see victor).
Wikipedia
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between and million years ago. It follows the Cambrian Period and is followed by the Silurian Period. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian periods, respectively. Lapworth, recognizing that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian periods, realized that they should be placed in a period of their own. While recognition of the distinct Ordovician period was slow in the United Kingdom, other areas of the world accepted it quickly. It received international sanction in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress.
Life continued to flourish during the Ordovician as it did in the Cambrian, although the end of the period was marked by a significant mass extinction. Invertebrates, namely molluscs and arthropods, dominated the oceans. There was considerable increase in biodiversity. Fish, the world's first true vertebrates, continued to evolve, and those with jaws may have first appeared late in the period. Life had yet to diversify on land. About 100 times as many meteorites slammed into Earth during the Ordovician compared with today.
Usage examples of "ordovician".
But there were also opportunities during the Ordovician for plants to come ashore in a big way.
The fight was finally settled in 1879 with the simple expedient of coming up with a new period, the Ordovician, to be inserted between the two.
The Ordovician extinction of 440 million years ago cleared the oceans of a lot of immobile filter feeders and, somehow, created conditions that favored darting fish and giant aquatic reptiles.
In the bottom of the ravine a shallow stream ran through pressure-metamorphosed Ordovician shale.
Empty platforms rushed past, their names in title: Cambrian, Ordovician, Silurian, Devonian, Permian, Triassic, Jurassic.
It was formed at the bottom of an Ordovician sea at least four hundred million years ago, which means this thing is an artifact from at least as long ago.
That idea never washed with me, since to get the 26-million-year periodicity you had to use the late Ordovician dyings, which were obviously just the result of plate tectonics moving the supercontinent Gondwanaland over the south pole, causing an ice age.
The Ordovician flora and fauna ignored them, having gotten to know them.
The Silurian period follows the Ordovician, and the Miocene epoch follows the Oligocene as surely as Wednesday follows Tuesday.
It took Valerius some time to identify it as Ordovician, straight from the battlefield, a command to give ground immediately in the face of the enemy.
After several false starts, they had found that Ordovician leatherwork was valued even if those buying it could not decipher the symbols burned and worked into the hides.
British paleontologist Richard Fortey has written with regard to a long-running twentieth-century dispute over where the boundary lies between the Cambrian and Ordovician.
Twenty percent drop in insolation: it was worse than any Terran ice age, more like the darkness after the great extinction events—the KT event, the Ordovician.
Twenty percent drop in insolation: it was worse than any Terran ice age, more like the darkness after the great extinction events-the KT event, the Ordovician.