Definition of Paleozoic in US English:

Paleozoic

adjective

Geology
  • 1Relating to or denoting the era between the Precambrian eon and the Mesozoic era.

    The Paleozoic lasted from about 570 million to 245 million years ago, its end being marked by mass extinctions. The Lower Paleozoic sub-era comprises the Cambrian, Ordovician, and Silurian periods, and the Upper Paleozoic sub-era comprises the Devonian, Carboniferous, and Permian periods. The era began with the first invertebrates with hard external skeletons, notably trilobites, and ended with the rise to dominance of the reptiles

    Formerly called "Primary"
    • ‘Cliffs forming the margins of rifts are thought to have developed in this way, with retreat occurring since the Late Cretaceous in Precambrian to Palaeozoic rocks.’
    • ‘Rocks of late Precambrian and early Paleozoic age have yielded a variety of tiny spine-like fossils of dominantly organic or weakly phosphatic composition.’
    • ‘Under a thin Jurassic conglomerate a Palaeozoic succession of interbedded reddened sandstone, mudstone and basalt was preserved.’
    • ‘Pre-Aptian structure reflects both Palaeozoic rifting and Mesozoic modification.’
    • ‘The Anatolian region has been formed by the amalgamation of smaller continental fragments that were formerly sited at the northern margin of Gondwana during late Palaeozoic and early Mesozoic times.’
    • ‘To the west of Siberia is the very large early Mesozoic and later Western Siberian Basin, which covers the Palaeozoic rocks and their sutures.’
    • ‘In addition to the dominant Precambrian and Paleozoic rocks, there are small deposits of Mesozoic rocks on the island as well.’
    • ‘The studied sequence at the transition to the axial zone in NE Sardinia is estimated to have a Precambrian to Palaeozoic age.’
    • ‘This idea is difficult to test, because data on Palaeozoic and Precambrian facies trends and structures are limited.’
    • ‘This tectonostratigraphy contains metamorphic rocks of both early Palaeozoic and Precambrian age with metamorphic grade generally increasing to the west.’
    1. 1.1as noun the Paleozoic The Paleozoic era or the system of rocks deposited during it.

Origin

Mid 19th century: from paleo- + Greek zōē ‘life’ + -ic.

Pronunciation

Paleozoic

/ˌpālēəˈzōik//ˌpeɪliəˈzoʊɪk/