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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]
Doomsday scenarios are possible events that could cause human extinction or the destruction of all or most life on Earth (a "true" or "major" Armageddon scenario), or alternatively a "lesser" Armageddon scenario in which the cultural, technological, environmental or social world is so greatly altered it could be considered like a different world.
The following list is incomplete by necessity, since the majority of extinctions are thought to be undocumented, and for many others there isn't a definitive, widely accepted last, or most recent record. According to the species-area theory, the present rate of extinction may be up to 140,000 species per year. [1]
The most famous of these mass extinction events — when an asteroid slammed into Earth 66 million years ago, dooming the dinosaurs and many other species — is also the most recent. But ...
Extinction events can be tracked by several methods, including geological change, ecological impact, extinction vs. origination rates, and most commonly diversity loss among taxonomic units. Most early papers used families as the unit of taxonomy, based on compendiums of marine animal families by Sepkoski (1982, 1992).
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The chart gives a comparison of the extinction event to other mass extinction events in Earth's history. Plotted is the extinction intensity, calculated from marine genera . Marcellus Formation Shale from Middle Devonian sedimentary rock, location of the Taghanic event rocks
Mass extinctions are characterized by the loss of at least 75% of species within a geologically short period of time (i.e., less than 2 million years). [18] [51] The Holocene extinction is also known as the "sixth extinction", as it is possibly the sixth mass extinction event, after the Ordovician–Silurian extinction events, the Late Devonian extinction, the Permian–Triassic extinction ...