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Ordovician
Or·do·vi·cian O0112400 (ôr′də-vĭsh′ən)adj. Of, relating to, or being the period of geologic time from about 488 to 444 million years ago, the second period of the Paleozoic Era. It is characterized by a major increase in marine biodiversity and the appearance of the supercontinent Gondwana. Some evidence suggests that the first land plants appeared at this time. See Table at geologic time.n. The Ordovician Period. [From Latin Ordovicēs, an ancient Celtic tribe of Wales, from Celtic Ordovices; see weik- in Indo-European roots.]Ordovician (ˌɔːdəʊˈvɪʃɪən) adj (Geological Science) of, denoting, or formed in the second period of the Palaeozoic era, between the Cambrian and Silurian periods, which lasted for 45 000 000 years during which marine invertebrates flourishedn (Geological Science) the Ordovician the Ordovician period or rock system[C19: from Latin Ordovices ancient Celtic tribe in N Wales]Or•do•vi•cian (ˌɔr dəˈvɪʃ ən) adj. 1. noting or pertaining to a geologic period of the Paleozoic Era, from 500 million to 425 million years ago, notable for the advent of fish. n. 2. the Ordovician Period or System. [1879; after the Ordovices (pl.) (< Latin) an ancient British tribe in N Wales] Or·do·vi·cian (ôr′də-vĭsh′ən) The second period of the Paleozoic Era, from about 505 to 438 million years ago, characterized by the appearance of primitive fishes. See Chart at geologic time.ThesaurusNoun | 1. | Ordovician - from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweedsOrdovician periodPaleozoic, Paleozoic era - from 544 million to about 230 million years ago | TranslationsordovicenseordovícicoOrdovicienordoviciumордовикOrdovician
Ordovician of, denoting, or formed in the second period of the Palaeozoic era, between the Cambrian and Silurian periods, which lasted for 45 000 000 years during which marine invertebrates flourished Ordovician[‚ȯrd·ə′vish·ən] (geology) The second period of the Paleozoic era, above the Cambrian and below the Silurian, from approximately 500 million to 440 million years ago. MedicalSeeOrdovician periodOrdovician Related to Ordovician: PermianSynonyms for Ordoviciannoun from 500 million to 425 million years agoSynonymsRelated Words |