from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Of or belonging to the geologic time, rock series, or sedimentary deposits of the last epoch of the Tertiary Period, characterized by the appearance of distinctly modern animals. See Table at geologic time.
  • n. The Pliocene Epoch or its system of deposits.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Of a geologic epoch within the Neogene period from about 5.3 to 1.7 million years ago; marked by the appearance of man's first ancestors.
  • proper n. The Pliocene epoch.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Of, pertaining to, or characterizing, the most recent division of the Tertiary age.
  • n. The Pliocene period or deposits.

from The Century Dictionary and Cyclopedia

  • n. In geology, the most recent of the divisions of the Tertiary proper. See Tertiary. Also spelled Pleiocene.
  • n. It was the final period of Tertiary time, during which the distribution of land and sea was very much as it is now. The uptilted deposits of this age, which are of world-wide distribution, consist of mostly unconsolidated sands, clays, and marls of marine and terrestrial origin, containing invertebrate and plant remains very similar to those of the present. The vertebrate fauna, on the other hand, differs widely, with numerous extinct types of large size, among which Dinotherium, Mastodon, Elephas, Equus, Hippopotamus, Rhinoceros, and Machærodus were of gigantic proportions. The Pliocene of southern Europe has been divided into the following stages: lower, Messinian or Plaisancian; middle, Astian; upper, Arnusian or Sicilian. In North America, marine deposits of this age are represented by the Floridian series of the Gulf coast and the Merced and San Pedro series of the Pacific coast; and the terrestrial deposits by the Palo Duro and Blanco beds of Texas and Oklahoma.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. from 13 million to 2 million years ago; growth of mountains; cooling of climate; more and larger mammals


from The American Heritage® Dictionary of the English Language, 4th Edition

Greek pleiōn, more; + -cene.



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