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  2. Cretaceous–Paleogene extinction event - Wikipedia

    en.wikipedia.org/wiki/Cretaceous–Paleogene...

    Scientists agree that all non-avian dinosaurs became extinct at the K–Pg boundary. The dinosaur fossil record has been interpreted to show both a decline in diversity and no decline in diversity during the last few million years of the Cretaceous, and it may be that the quality of the dinosaur fossil record is simply not good enough to permit ...

  3. Timeline of Cretaceous–Paleogene extinction event research

    en.wikipedia.org/wiki/Timeline_of_Cretaceous...

    John M. Cys argued that dinosaurs went extinct because they were unable to hibernate during the winter, leaving them doomed by Earth's changing climate. [23] 1968. Daniel I. Axelrod and Harry Paul Bailey proposed that the dinosaurs were driven extinct when Earth's climate began exhibiting more marked seasons rather than stable conditions year ...

  4. Dinosaur - Wikipedia

    en.wikipedia.org/wiki/Dinosaur

    A 2016 estimate put the number of dinosaur species living in the Mesozoic at 1,543–2,468, [24] [25] compared to the number of modern-day birds (avian dinosaurs) at 10,806 species. [26] Extinct dinosaurs, as well as modern birds, include genera that are herbivorous and others carnivorous, including seed-eaters, fish-eaters, insectivores, and ...

  5. Timeline of the evolutionary history of life - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the...

    More than 99 percent of all species that ever lived (over five billion) [1] are estimated to be extinct. [ 2 ] [ 3 ] Estimates on the number of Earth's current species range from 10 million to 14 million, [ 4 ] with about 1.2 million or 14% documented, the rest not yet described . [ 5 ]

  6. History of paleontology - Wikipedia

    en.wikipedia.org/wiki/History_of_paleontology

    The history of paleontology traces the history of the effort to understand the history of life on Earth by studying the fossil record left behind by living organisms. Since it is concerned with understanding living organisms of the past, paleontology can be considered to be a field of biology, but its historical development has been closely tied to geology and the effort to understand the ...

  7. Scientists think they've found the origin of the asteroid ...

    www.aol.com/scientists-think-theyve-found-origin...

    The asteroid that killed most dinosaurs 66 million years ago left behind traces of its own origin. Researchers think they know where the Chicxulub impactor came from based on levels of ruthenium.

  8. Scientists believe they have finally uncovered what killed ...

    www.aol.com/news/scientists-believe-finally...

    The amount of dust strangling the atmosphere is thought to have been about 2,000 gigatonnes; more than 11 times the weight of Mount Everest. Researchers ran simulations on sediment found at a ...

  9. Alvarez hypothesis - Wikipedia

    en.wikipedia.org/wiki/Alvarez_hypothesis

    He further posits that the mass extinction of dinosaurs occurred within 33,000 years of this date. [ 8 ] In April 2019, a paper was published in PNAS which describes evidence from a fossil site in North Dakota that the authors say provides a "postimpact snapshot" of events after the asteroid collision "including ejecta accretion and faunal mass ...