Portal:Paleozoic

The Paleozoic Portal

Introduction

The Paleozoic (IPA: /ˌpæli.əˈzoʊ.ɪk,-i.oʊ-, ˌpeɪ-/ PAL-ee-ə-ZOH-ik, -⁠ee-oh-, PAY-; or Palaeozoic) Era is the first of three geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma at the start of the Mesozoic Era. The Paleozoic is subdivided into six geologic periods (from oldest to youngest):

Some geological timescales divide the Paleozoic informally into early and late sub-eras: the Early Paleozoic consisting of the Cambrian, Ordovician and Silurian; the Late Paleozoic consisting of the Devonian, Carboniferous and Permian.

The name Paleozoic was first used by Adam Sedgwick (1785-1873) in 1838 to describe the Cambrian and Ordovician periods. It was redefined by John Phillips (1800–1874) in 1840 to in cover the Cambrian to Permian periods. It is derived from the Greek palaiós (παλαιός, "old") and zōḗ (ζωή, "life") meaning "ancient life".

The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian 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. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean but eventually transitioned onto land, and by the late Paleozoic, 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 synapsids and diapsids were dominant and the first modern plants (conifers) appeared. (Full article...)

Selected article on the Paleozoic world and its legacies

Bacteria (/bækˈtɪəriə/ ; singular: bacterium) constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in mosthabitats on the planet. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in plants and animals and have flourished in manned space vehicles.

There are approximately 5×1030 bacteria on Earth, forming a biomass that exceeds that of all plants and animals. Bacteria are vital in recycling nutrients, with many steps in nutrient cycles depending on these organisms, such as the fixation of nitrogen from the atmosphere and putrefaction. In the biological communities surrounding hydrothermal vents and cold seeps, bacteria provide the nutrients needed to sustain life by converting dissolved compounds such as hydrogen sulphide and methane to energy. Most bacteria have not been characterised, and only about half of the phyla of bacteria have species that can be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles. (see more...)

Selected article on the Paleozoic in human science, culture and economics

Edward Drinker Cope (left) and Othniel Charles Marsh (right).
Edward Drinker Cope (left) and Othniel Charles Marsh (right).

The Bone Wars is the name given to a period of intense fossil speculation and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope and Othniel Charles Marsh. The two paleontologists used underhanded methods to out-compete the other in the field, resorting to bribery, theft, and destruction of bones. The scientists also attacked each other in scientific publications, attempting to ruin the other's credibility and cut off his funding.

Originally colleagues who were civil to each other, Cope and Marsh became bitter enemies after several personal slights between them. Their pursuit of bones led them west to rich bone beds in Colorado, Nebraska, and Wyoming. From 1877 to 1892, both paleontologists used their wealth and influence to finance their own expeditions and to procure services and fossils from dinosaur hunters. By the end of the Bone Wars, both men exhausted their funds in fueling their intense rivalry.

Cope and Marsh were financially and socially ruined by their efforts to disgrace each other, but their contributions to science and the field of paleontology were massive; the scientists left behind tons of unopened boxes of fossils on their deaths. The feud between the two men led to over 142 new species of dinosaurs being discovered and described. Several historical books and fictional adaptations have also been published about this period of intense paleontological activity. (see more...)

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Skeletal mount of Casea.

Skeletal mount of Casea.
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Did you know?

Restoration Tiarajudens.
Restoration Tiarajudens.
  • ... that a fossil of Concavodonta described in 1843 has been lost?

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Topics

Geochronology - Cambrian (Early - Middle - Late) - Ordovician (Early - Middle - Late) - Silurian (Early - Wenlock - Ludlow - Late) - Devonian (Early - Middle - Late) - Carboniferous (Mississippian - Pennsylvanian)- Permian (Early - Middle - Late)

Paleozoic landmasses - Pannotia - Baltica - Laurentia - Siberia - Avalonia -Gondwanaland - Laurentia - Euramerica - Gondwana - South China- Pangaea

Major Paleozoic events - Cambrian Explosion - Cambrian substrate revolution - End-Botomian mass extinction - Cambrian–Ordovician extinction event

Cambrian biota appearances - Brachiopods - Burgess shale fauna - Cephalopods - Chitons - Crustaceans - Echinoderms - Foraminiferans - Graptolites - Radiolarians -Trilobites - Vertebrates

Ordovician biota appearances - Conodonts - Echinoids

Silurian biota appearances - Fungi - Galeaspids - Heterostracans - Land plants - Pituriaspids -Ray-finned fishes - Scorpions - Trigonotarbids

Devonian biota appearances - Crabs - Ferns - Harvestmen - Lichens - Lycophytes - Mites -Springtails - Stoneworts - Trimerophytes

Carboniferous biota appearances - Amphibians - Hagfishes - Insects - Ratfishes - Reptiles -Synapsids

Permian biota appearances - Beetles - Pelycosaurs - Temnospondyls - Therapsids

Fossil sites - Bear Gulch Limestone - Beecher's Trilobite Bed - Gilboa Forest - Grenfell fossil site - Hamilton Quarry - Mazon Creek fossil beds - Mississippi Petrified Forest - Walcott Quarry - Walcott–Rust quarry - Yea Flora Fossil Site

Stratigraphic units - Burgess Shale - Chazy Formation - Columbus Limestone - Fezouata formation - Francis Creek Shale - Gogo Formation - Holston Formation - Hunsrück Slate - Jeffersonville Limestone - Karoo Supergroup - Keyser Formation - Kope Formation - Llewellyn Formation - Mahantango Formation - Maotianshan Shales - Marcellus Formation - Millstone Grit - New Albany Shale - Old Port Formation - Old Red Sandstone - Potsdam Sandstone - Red Beds of Texas and Oklahoma - Rhynie chert - Shawangunk Formation - St. Peter Sandstone - Tuscarora Formation

History - History of paleontology - Timeline of paleontology - The Great Devonian Controversy

Researchers - Charles Emerson Beecher - Ermine Cowles Case - Edward Drinker Cope - Henry De la Beche - Stephen Jay Gould - Increase A. Lapham - Charles Lapworth - Simon Conway Morris - Roderick Murchison - Alfred Sherwood Romer - Neil Shubin - Charles Doolittle Walcott

Culture - Animal Armageddon - The Day The Earth Nearly Died - List of creatures in the Walking with... series - Lost Worlds, Vanished Lives - Miracle Planet - Prehistoric Park - Sea Monsters - Treatise on Invertebrate Paleontology - Vertebrate Paleontology - Walking with Monsters - Wonderful Life

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Subcategories

Paleozoic
Paleozoic by continent
Paleozoic geochronology
Paleozoic geology
Paleozoic life
Paleozoic paleogeography
Paleozoic paleontological sites
Paleozoic portals
Paleozoic stubs

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