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Timeline Of Cretaceous–Paleogene Extinction Event Research
Since the 19th century, a significant amount of research has been conducted on the Cretaceous–Paleogene extinction event, the mass extinction that ended the dinosaur-dominated Mesozoic Era and set the stage for the Age of Mammals, or Cenozoic Era. A chronology of this research is presented here. Paleontologists have recognized that a significant transition occurred between the Mesozoic and Cenozoic eras at least since the 1820s. Around this time dinosaur fossils were first being described in the scientific literature. Nevertheless, so few dinosaurs were known that the significance of their passing went unrecognized and little scientific effort was exerted toward finding an explanation. As more and more different kinds of dinosaurs were discovered, their extinction and replacement by mammals was recognized as significant but dismissed with little examination as a natural consequence of the mammals' supposed innate superiority. Consequently, paleontologist Michael J. Benton has c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chicxulub Impact - Artist Impression
The Chicxulub crater () is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is offshore near the community of Chicxulub Pueblo, Chicxulub, after which it is named. It was formed slightly over 66 million years ago when a large asteroid, about in diameter, struck Earth. The crater is estimated to be in diameter and in depth. It is List of impact craters on Earth#10 Ma or more, the second largest confirmed impact structure on Earth, and the only one whose peak ring is intact and directly accessible for scientific research. The crater was discovered by Antonio Camargo and Glen Penfield, geophysicists who had been looking for petroleum in the Yucatán Peninsula during the late 1970s. Penfield was initially unable to obtain evidence that the geological feature was a crater and gave up his search. Later, through contact with Alan R. Hildebrand in 1990, Penfield obtained samples that suggested it was an impact feature. Evidence for the crater's impact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
