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The Cretaceous–Paleogene (K–Pg) extinction event, [a] also known as the K–T extinction, [b] was the mass extinction of three-quarters of the plant and animal species on Earth [2] [3] approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs.
Late Devonian: 375 million years ago, 75% of species lost, including most trilobites; End Permian, The Great Dying: 251 million years ago, 96% of species lost, including tabulate corals, and most trees and synapsids; End Triassic: 200 million years ago, 80% of species lost, including all conodonts
The Cretaceous (IPA: / k r ɪ ˈ t eɪ ʃ ə s / krih-TAY-shəss) [2] is a geological period that lasted from about 143.1 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77 million years, it is the ninth and longest geological period of the entire Phanerozoic.
Swisher and others dated the formation of the Chicxulub Crater to 65 million years ago. [39] More precisely, they dated igneous rock from the Chicxulub crater to 64.98 million years ago. [100] Sheehan and Fastovsky found terrestrial vertebrates to be the primary victims of the end Cretaceous extinction event, with 88% of their biodiversity lost.
The evidence regarding plants is less clear, but new taxa became dominant after the extinction. [17] The "Great Dying" had enormous evolutionary significance: on land, it ended the primacy of early synapsids. The recovery of vertebrates took 30 million years, [18] but the vacant niches created the opportunity for archosaurs to become ascendant.
When an asteroid wiped out the dinosaurs, new animals and plants competed to survive on a changing planet. Grapes were the unlikely winners 60 million years ago.
The date of the impact coincides precisely with the Cretaceous–Paleogene boundary (K–Pg boundary), slightly more than 66 million years ago. [7] The crater is estimated to be over 150 km (93 mi) in diameter [10] and 20 km (12 mi) in depth, well into the continental crust of the region of about 10–30 km (6.2–18.6 mi) depth.
Land plants evolved from a group of freshwater green algae, perhaps as early as 850 mya, [3] but algae-like plants might have evolved as early as 1 billion years ago. [2] The closest living relatives of land plants are the charophytes, specifically Charales; if modern Charales are similar to the distant ancestors they share with land plants, this means that the land plants evolved from a ...