Also found in: Thesaurus, Medical, Encyclopedia, Wikipedia.
Related to Ordovician: Permian
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.
The Ordovician Period.
[From Latin Ordovicēs, an ancient Celtic tribe of Wales, from Celtic Ordovices; see weik- in Indo-European roots.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(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 flourished
(Geological Science) the Ordovician the Ordovician period or rock system
[C19: from Latin Ordovices ancient Celtic tribe in N Wales]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
Or•do•vi•cian(ˌɔr dəˈvɪʃ ən)
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]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Switch to new thesaurus
|Noun||1.||Ordovician - from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds|
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.