Search results
Results From The WOW.Com Content Network
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.
Badlands near Drumheller, Alberta, where erosion has exposed the Cretaceous–Paleogene boundary. The End Cretaceous extinction, or the K–Pg extinction (formerly K–T extinction) occurred at the Cretaceous (Maastrichtian) – Paleogene transition. [19] The event was formerly called the Cretaceous-Tertiary or K–T extinction or K–T ...
c. 66.038 ± 0.011 Ma – Cretaceous-Paleogene extinction event at the end of the Cretaceous Period marks the end of the Mesozoic era and the age of the dinosaurs; start of the Paleogene Period and the current Cenozoic era.
For example, the Cretaceous–Paleogene extinction event, marks the lower boundary of the Paleogene System/Period and thus the boundary between the Cretaceous and Paleogene systems/periods. For divisions prior to the Cryogenian , arbitrary numeric boundary definitions ( Global Standard Stratigraphic Ages , GSSAs) are used to divide geologic time.
A study aiming to quantify the habitat of latest Cretaceous North American dinosaurs, based on data from fossil occurrences and climatic and environmental modelling, and evaluating its implications for inferring whether dinosaur diversity was in decline prior to the Cretaceous–Paleogene extinction event, was published by Chiarenza et al ...
The first known mass extinction was the Great Oxidation Event 2.4 billion years ago, which killed most of the planet's obligate anaerobes. Researchers have identified five other major extinction events in Earth's history, with estimated losses below: [11] End Ordovician: 440 million years ago, 86% of all species lost, including graptolites
By the time the Cretaceous-Paleogene, or K/Pg, extinction event was over, about three-quarters of species alive at the time of impact had disappeared forever.
The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs, pterosaurs, and large marine reptiles, died out, widely thought to have been caused by the impact of a large asteroid that formed the Chicxulub crater in the Gulf of Mexico.