La era Paleozoica, Paleozoico o era Primaria es una división de la escala temporal geológica de más de 290 millones de años (m.a.) de duración, que se inició hace 542,0 ± 1,0 m.a. y acabó hace unos 251,0 ± 0,4 m.a. Es la primera era del Eón Fanerozoico, entre el Eón Proterozoico y la Era Mesozoica. Su nombre procede del griego «palaio/παλαιο» («viejo») y «zoe/ζωη» («vida»), que significa «vida antigua». Geológicamente, el Paleozoico se inicia poco después de la desintegración del supercontinente Pannotia y acaba con la formación del supercontinente Pangea. Durante la mayor parte de la era, la superficie de la Tierra se divide en un número relativamente pequeño de continentes. El Paleozoico abarca desde la proliferación de animales con concha o exoesqueleto hasta el momento en que el mundo empezó a ser dominado por los grandes reptiles y por plantas relativamente modernas, como las coníferas.

Leer el artículo completo en Wikipedia · CC-BY-SA

The Paleozoic (or Palaeozoic) Era (pronunciation: /ˌpeɪliəˈzoʊɪk, ˌpæ-/; from the Greek palaios (παλαιός), "old" and zoe (ζωή), "life", meaning "ancient life") is the earliest of three geologic eras of the Phanerozoic Eon, from 541 to 252.17 million years ago. It is the longest of the Phanerozoic eras, and is subdivided into six geologic periods (from oldest to youngest): the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon, and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian Period witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Fish, arthropods, amphibians, anapsida, synapsida, euryapsida and diapsida all evolved during the Paleozoic. Life began in the ocean but eventually transitioned onto land, and by the late Paleozoic, it was dominated by various forms of organisms. Great forests of primitive plants covered the continents, many of which formed the coal beds of Europe and eastern North America. Towards the end of the era, large, sophisticated diapsida and synapsida were dominant and the first modern plants (conifers) appeared. The Paleozoic Era ended with the largest mass extinction in Earth's history, the Permian–Triassic extinction event. The effects of this catastrophe were so devastating that it took life on land 30 million years into the Mesozoic Era to recover. Recovery of life in the sea may have been much faster.

Leer el artículo completo en Wikipedia · CC-BY-SA