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Dresbachian extinction event: 502 Ma: End-Botomian extinction event: 517 Ma: Precambrian: End-Ediacaran extinction: 542 Ma: Anoxic event [45] 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 (also known as a mass extinction or biotic crisis) 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.
The extinction's rapidity is a controversial issue because some researchers think the extinction was the result of a sudden event, while others argue that it took place over a long period. The exact length of time is difficult to determine because of the Signor–Lipps effect , where the fossil record is so incomplete that most extinct species ...
A growing number of scientists believe a sixth mass extinction event of a magnitude equal to the prior five has been unfolding for the past 10,000 years as humans have made their mark around the ...
A conference dedicated to the end-Cretaceous extinction event was held at Utah's Snowbird ski resort. [45] By this point in time, 36 K–T boundary sites with anomalously high iridium levels had been identified. [46] At the conference, Yale geochemist Karl Turekian disputed the impact hypothesis.
In the geological timescale, the Llandovery Epoch (from 443.8 ± 1.5 million years ago to 433.4 ± 0.8 million years ago) occurred at the beginning of the Silurian Period. . The Llandoverian Epoch follows the massive Ordovician-Silurian extinction events, which led to a large decrease in biodiversity and an opening up of ecosyste
The reasons for extinction range from natural occurrences, such as shifts in the Earth's ecosystem or natural disasters, to human influences on nature by the overuse of natural resources, hunting and destruction of natural habitats.
The Changhsingian ended with the Permian–Triassic extinction event, the largest mass extinction event of the Phanerozoic Era, when both global biodiversity and alpha diversity (community-level diversity) were devastated. [9]