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
Of a geologic era within the Phanerozoic eon and 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
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
- A geologic era that is marked by the culmination of all classes of invertebrates except insects and the appearance of seed-bearing plants, amphibians and reptiles The Paleozoic era is divided into seven periods designated by inundations of seas The Mississippian and Pennsylvanian periods of Kentucky occurred during the Paleozoic era
An era of geologic time, from the end of the Precambrian to the beginning of the Mesozoic, spanning the time between 544 and 248 million years ago The word Paleozoic is from Greek and means "old life "
The era containing the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods It is usually divided into upper and lower with three periods in each division