This is a list of extinction events , both mass and minor: [1]
Period or supereon | Extinction | Date | Probable causes [2] |
---|---|---|---|
Quaternary | Holocene extinction | c. 10,000 BC – Ongoing | Humans [3] |
Quaternary extinction event | 640,000, 74,000, and 13,000 years ago | Unknown; may include climate changes, massive volcanic eruptions and Humans (largely by human overhunting) [4] [5] [6] | |
Neogene | Pliocene–Pleistocene boundary extinction | 2 Ma | Possible causes include a supernova [7] [8] or the Eltanin impact [9] [10] |
Middle Miocene disruption | 14.5 Ma | Climate change due to change of ocean circulation patterns. Milankovitch cycles may have also contributed [11] | |
Paleogene | Eocene–Oligocene extinction event | 33.9 Ma | Multiple causes including global cooling, polar glaciation, falling sea levels, and the Popigai impactor [12] |
Cretaceous | Cretaceous–Paleogene extinction event | 66 Ma | Chicxulub impactor; the volcanism which resulted in the formation of the Deccan Traps may have contributed. [13] |
Cenomanian-Turonian boundary event | 94 Ma | Most likely underwater volcanism associated with the Caribbean large igneous province, which would have caused global warming and acidic oceans [14] | |
Aptian extinction | 117 Ma | Unknown, but may be due to volcanism of the Rajmahal Traps [15] | |
Jurassic | End-Jurassic (Tithonian) | 145 Ma | No longer regarded as a major extinction but rather a series of lesser events due to bolide impacts, eruptions of flood basalts, climate change and disruptions to oceanic systems [16] |
Pliensbachian-Toarcian extinction (Toarcian turnover) | 186-178 Ma | Formation of the Karoo-Ferrar Igneous Provinces [17] | |
Triassic | Triassic–Jurassic extinction event | 201 Ma | Possible causes include gradual climate changes, volcanism from the Central Atlantic magmatic province [18] or an impactor [19] |
Carnian Pluvial Event | 230 Ma | Wrangellia flood basalts, [20] or the uplift of the Cimmerian orogeny | |
Olenekian-Anisian boundary event | 247 Ma | Ocean acidification [21] | |
Smithian-Spathian boundary event | 249 Ma | Late eruptions of the Siberian Traps | |
Griesbachian-Dienerian boundary-event | 252 | Late eruptions of the Siberian Traps [22] | |
Permian | Permian–Triassic extinction event | 252 Ma | Large igneous province (LIP) eruptions [23] from the Siberian Traps, [24] an impact event (the Wilkes Land Crater), [25] an Anoxic event, [26] an Ice age, [27] or other possible causes |
End-Capitanian extinction event | 260 Ma | Volcanism from the Emeishan Traps, [28] resulting in global cooling and other effects | |
Olson's Extinction | 270 Ma | Unknown. Possibly a change in climate. | |
Carboniferous | Carboniferous rainforest collapse | 305 Ma | Possiblities include a series of rapid changes in climate, or volcanism of the Skagerrak-Centered Large Igneous Province [29] |
Serpukhovian extinction | ~ 325 Ma | Onset of the Late Paleozoic icehouse | |
Devonian | Hangenberg event | 359 Ma | Anoxia, possibly related to the Famennian glaciation or volcanic activity, Supernova [30] |
Late Devonian extinction (Kellwasser event) | 372 Ma | Viluy Traps; [31] Woodleigh Impactor? [2] | |
Taghanic Event | ~384 Ma | Anoxia | |
Kačák Event | ~388 Ma | Anoxia | |
Silurian | Lau event | 420 Ma | Changes in sea level and chemistry? [32] |
Mulde event | 424 Ma | Global drop in sea level? [33] | |
Ireviken event | 428 Ma | Deep-ocean anoxia; [34] Milankovitch cycles? [35] | |
Ordovician | Late Ordovician mass extinction | 445-444 Ma | Global cooling and sea level drop, and/or global warming related to volcanism and anoxia [36] |
Cambrian | Cambrian–Ordovician extinction event | 488 Ma | Kalkarindji Large Igneous Province? [37] |
Dresbachian extinction event | 502 Ma | ||
End-Botomian extinction event | 517 Ma | ||
Precambrian | End-Ediacaran extinction | 542 Ma | Anoxic event [38] |
Great Oxygenation Event | 2400 Ma | Rising oxygen levels in the atmosphere due to the development of photosynthesis as well as possible Snowball Earth event. (see: Huronian glaciation.) |
An extinction event is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the background extinction rate and the rate of speciation. Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from disagreement as to what constitutes a "major" extinction event, and the data chosen to measure past diversity.
Approximately 251.9 million years ago, the Permian–Triassicextinction event forms the boundary between the Permian and Triassic geologic periods, and with them the Paleozoic and Mesozoic eras respectively. It is the Earth's most severe known extinction event, with the extinction of 57% of biological families, 83% of genera, 81% of marine species and 70% of terrestrial vertebrate species. It is also the largest known mass extinction of insects. It is the largest of the "Big Five" mass extinctions of the Phanerozoic. There is evidence for one to three distinct pulses, or phases, of extinction.
The Triassic is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic.
The Triassic–Jurassic (Tr-J) extinction event (TJME), often called the end-Triassic extinction, was a Mesozoic extinction event that marks the boundary between the Triassic and Jurassic periods, 201.4 million years ago, and is one of the top five major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans. In the seas, the entire class of conodonts and 23–34% of marine genera disappeared. On land, all archosauromorphs other than crocodylomorphs, pterosaurs, and dinosaurs became extinct; some of the groups which died out were previously abundant, such as aetosaurs, phytosaurs, and rauisuchids. Some remaining non-mammalian therapsids and many of the large temnospondyl amphibians had become extinct prior to the Jurassic as well. However, there is still much uncertainty regarding a connection between the Tr-J boundary and terrestrial vertebrates, due to a lack of terrestrial fossils from the Rhaetian (latest) stage of the Triassic. What was left fairly untouched were plants, crocodylomorphs, dinosaurs, pterosaurs and mammals; this allowed the dinosaurs, pterosaurs, and crocodylomorphs to become the dominant land animals for the next 135 million years.
The Late Ordovician mass extinction (LOME), sometimes known as the end-Ordovician mass extinction or the Ordovician-Silurian extinction, is the first of the "big five" major mass extinction events in Earth's history, occurring roughly 445 million years ago (Ma). It is often considered to be the second-largest known extinction event, in terms of the percentage of genera that became extinct. Extinction was global during this interval, eliminating 49–60% of marine genera and nearly 85% of marine species. Under most tabulations, only the Permian-Triassic mass extinction exceeds the Late Ordovician mass extinction in biodiversity loss. The extinction event abruptly affected all major taxonomic groups and caused the disappearance of one third of all brachiopod and bryozoan families, as well as numerous groups of conodonts, trilobites, echinoderms, corals, bivalves, and graptolites. Despite its taxonomic severity, the Late Ordovician mass extinction did not produce major changes to ecosystem structures compared to other mass extinctions, nor did it lead to any particular morphological innovations. Diversity gradually recovered to pre-extinction levels over the first 5 million years of the Silurian period.
The Siberian Traps is a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. The massive eruptive event that formed the traps is one of the largest known volcanic events in the last 500 million years.
The Late Devonian extinction consisted of several extinction events in the Late Devonian Epoch, which collectively represent one of the five largest mass extinction events in the history of life on Earth. The term primarily refers to a major extinction, the Kellwasser event, also known as the Frasnian-Famennian extinction, which occurred around 372 million years ago, at the boundary between the Frasnian stage and the Famennian stage, the last stage in the Devonian Period. Overall, 19% of all families and 50% of all genera became extinct. A second mass extinction called the Hangenberg event, also known as the end-Devonian extinction, occurred 359 million years ago, bringing an end to the Famennian and Devonian, as the world transitioned into the Carboniferous Period.
The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0.5 – 259.1 ± 0.4 Mya. The series saw the rise of the therapsids, a minor extinction event called Olson's Extinction and a significant mass extinction called the end-Capitanian extinction event. The Guadalupian was previously known as the Middle Permian.
Oceanic anoxic events or anoxic events (anoxia conditions) describe periods wherein large expanses of Earth's oceans were depleted of dissolved oxygen (O2), creating toxic, euxinic (anoxic and sulfidic) waters. Although anoxic events have not happened for millions of years, the geologic record shows that they happened many times in the past. Anoxic events coincided with several mass extinctions and may have contributed to them. These mass extinctions include some that geobiologists use as time markers in biostratigraphic dating. On the other hand, there are widespread, various black-shale beds from the mid-Cretaceous which indicate anoxic events but are not associated with mass extinctions. Many geologists believe oceanic anoxic events are strongly linked to the slowing of ocean circulation, climatic warming, and elevated levels of greenhouse gases. Researchers have proposed enhanced volcanism (the release of CO2) as the "central external trigger for euxinia."
In the geologic timescale, the Capitanian is an age or stage of the Permian. It is also the uppermost or latest of three subdivisions of the Guadalupian Epoch or Series. The Capitanian lasted between 264.28 and 259.51 million years ago. It was preceded by the Wordian and followed by the Wuchiapingian.
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and 247.2 Ma. Rocks from this epoch are collectively known as the Lower Triassic Series, which is a unit in chronostratigraphy.
In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between 251.2 Ma and 247.2 Ma. The Olenekian is sometimes divided into the Smithian and the Spathian subages or substages. The Olenekian follows the Induan and is followed by the Anisian.
The Daptocephalus Assemblage Zone is a tetrapod assemblage zone or biozone found in the Adelaide Subgroup of the Beaufort Group, a majorly fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. This biozone has outcrops located in the upper Teekloof Formation west of 24°E, the majority of the Balfour Formation east of 24°E, and the Normandien Formation in the north. It has numerous localities which are spread out from Colesberg in the Northern Cape, Graaff-Reniet to Mthatha in the Eastern Cape, and from Bloemfontein to Harrismith in the Free State. The Daptocephalus Assemblage Zone is one of eight biozones found in the Beaufort Group and is considered Late Permian (Lopingian) in age. Its contact with the overlying Lystrosaurus Assemblage Zone marks the Permian-Triassic boundary.
The Emeishan Traps constitute a flood basalt volcanic province, or large igneous province, in south-western China, centred in Sichuan province. It is sometimes referred to as the Permian Emeishan Large Igneous Province or Emeishan Flood Basalts. Like other volcanic provinces or "traps", the Emeishan Traps are multiple layers of igneous rock laid down by large mantle plume volcanic eruptions. The Emeishan Traps eruptions were serious enough to have global ecological and paleontological impact.
The fossil record of fire first appears with the establishment of a land-based flora in the Middle Ordovician period, 470 million years ago, permitting the accumulation of oxygen in the atmosphere as never before, as the new hordes of land plants pumped it out as a waste product. When this concentration rose above 13%, it permitted the possibility of wildfire. Wildfire is first recorded in the Late Silurian fossil record, 420 million years ago, by fossils of charcoalified plants. Apart from a controversial gap in the Late Devonian, charcoal is present ever since. The level of atmospheric oxygen is closely related to the prevalence of charcoal: clearly oxygen is the key factor in the abundance of wildfire. Fire also became more abundant when grasses radiated and became the dominant component of many ecosystems, around 6 to 7 million years ago; this kindling provided tinder which allowed for the more rapid spread of fire. These widespread fires may have initiated a positive feedback process, whereby they produced a warmer, drier climate more conducive to fire.
The Carnian pluvial episode (CPE), often called the Carnian pluvial event, was an interval of major change in global climate that was synchronous with significant changes in Earth's biota both in the sea and on land. It occurred during the latter part of the Carnian Stage, a subdivision of the late Triassic period, and lasted for perhaps 1-2 million years. The CPE represents a significant episode in the evolution and diversification of many taxa that are important today, among them some of the earliest dinosaurs, lepidosaurs, pterosaurs and true mammals. In the marine realm it saw the first appearance among the microplankton of coccoliths and dinoflagellates, with the latter linked to the rapid diversification of scleractinian corals through the establishment of symbiotic zooxanthellae within them. The CPE also saw the extinction of many aquatic invertebrate species, especially among the ammonoids, bryozoa, and crinoids.
The Lilliput effect is a decrease in body size in animal species that have survived a major extinction. There are several hypotheses as to why these patterns appear in the fossil record, some of which are: the survival of small taxa, dwarfing of larger lineages, and the evolutionary miniaturization from larger ancestral stocks. The term was coined in 1993 by Adam Urbanek in his paper concerning the extinction of graptoloids and is derived from the island of Lilliput inhabited by a miniature race of people in Gulliver’s Travels. This size decrease may just be a temporary phenomenon restricted to the survival period of the extinction event. In 2019 Atkinson et al. coined the term the Brobdingnag effect to describe a related phenomenon operating in the opposite direction, whereby new species evolving after the Triassic-Jurassic mass extinction originated at small body sizes before undergoing a size increase. The term is also from Gulliver's Travels where Brobnignag is a land inhabited by a race of giants.
The Capitanian mass extinction event, also known as the end-Guadalupian extinction event, the Guadalupian-Lopingian boundary mass extinction, the pre-Lopingian crisis, or the Middle Permian extinction, was an extinction event that predated the end-Permian extinction event. The mass extinction occurred during a period of decreased species richness and increased extinction rates near the end of the Middle Permian, also known as the Guadalupian epoch. It is often called the end-Guadalupian extinction event because of its initial recognition between the Guadalupian and Lopingian series; however, more refined stratigraphic study suggests that extinction peaks in many taxonomic groups occurred within the Guadalupian, in the latter half of the Capitanian age. The extinction event has been argued to have begun around 262 million years ago with the Late Guadalupian crisis, though its most intense pulse occurred 259 million years ago in what is known as the Guadalupian-Lopingian boundary event.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2020.
Paul Barry Wignall is a British palaeontologist and sedimentologist. He is best known for his research on mass extinctions in the marine realm., particularly via the interpretation of black shales.
Moreover, we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be annihilated or at least committed to extinction by the end of this century.
Although some debate persists, most of the evidence suggests that humans were responsible for extinction of this Pleistocene fauna, and we continue to drive animal extinctions today through the destruction of wild lands, consumption of animals as a resource or a luxury, and persecution of species we see as threats or competitors.
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