from The American Heritage® Dictionary of the English Language, 5th Edition.

  • adjective Of, relating to, or being the era of geologic time from about 542 to 251 million years ago. The Paleozoic Era includes the Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, and Permian Periods and is characterized by the appearance of marine invertebrates, primitive fishes, land plants, and primitive reptiles. The end of this era is marked by the largest recorded mass extinction in the earth's history, in which 90 percent of marine life forms were wiped out.
  • noun The Paleozoic Era.

from The Century Dictionary.

  • In geology, belonging to or constituting a geological formation characterized by the presence of ancient forms of life: applied to the oldest division of the geological series, beginning with the lowest stratified fossiliferous group, and extending upward to the base of the Triassic, or to the top of the Permian.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective (Geol.) Of or pertaining to, or designating, the older division of geological time during which life is known to have existed, including the Silurian, Devonian, and Carboniferous ages, and also to the life or rocks of those ages. See Chart of geology.
  • noun (Geol.) The Paleozoic time or strata.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • adjective geology Of a geologic era within the Phanerozoic eon that comprises the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods from about 542 to 250 million years ago, from the age of trilobites to that of reptiles.
  • proper noun geology The Paleozoic era.

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

  • noun from 544 million to about 230 million years ago
  • adjective of or relating to or denoting the Paleozoic era


from Wiktionary, Creative Commons Attribution/Share-Alike License

paleo- + -zoic


  • Müller & Tsuji, Impedance-Matching Hearing in Paleozoic Reptiles: Evidence of Advanced Sensory Perception at an Early Stage of Amniote Evolution, PLoS ONE 2007.

    A Decade Spanning Single Exchange

  • The beginning of the Paleozoic is the definitional start of the Edenic Period, a time span in evolutionary biology that demarcates the initial time taken for the computation of background extinction rates of biota; the Edenic Period is taken to end with the ascent of modern man (e.g. approximately 50,000 to 10,000 years before present).


  • The second volume of the geological record, called the Paleozoic (Greek, PALAIOS, ancient; ZOE, life), has come down to us far less mutilated and defaced than has the first volume, which contains the traces of the most ancient life of the globe.

    The Elements of Geology

  • They lived through "Paleozoic" time, which, according to Dana, represents twelve of the sixteen parts of all geological time, beginning with the Primordial; or, calling the whole geological time 48 millions of years, the trilobites lived 36 million of years, or three-fourths of all geological time.

    Evolution An Investigation and a Critique

  • The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles.

    February 2009

  • The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles.

    NEW ON THE NET- January 2009

  • Georgetown is still on top, as they've been since the late Paleozoic, although five other teams got first-place votes.

    Atlantic 11 Week 9: Georgetown. Your Town.

  • The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles.


  • Â Terry makes several jumps in time — to Siberia, then to the British Isles, then to the Paleozoic era and then to 2026 — where he finds himself with an aged Eric Bellmont.

    New episode of Time Jumper arrives on iTunes | Major Spoilers - Comic Book Reviews and News

  • You can almost hear giant Paleozoic dragonflies pausing to the mechanical alien sound of the watch.

    But a Moment Ago « A Fly in Amber


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