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It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the current era, the Cenozoic. In the geologic record , the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary or K–T boundary , which can be found throughout the world in marine and terrestrial rocks.
Luis Walter Alvarez, left, and his son Walter, right, at the K–T Boundary in Gubbio, Italy, 1981. The Alvarez hypothesis posits that the mass extinction of the non-avian dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth.
Researchers report that the Cretaceous Chicxulub asteroid impact that resulted in the extinction of non-avian dinosaurs 66 million years ago, also rapidly acidified the oceans producing ecological collapse and long-lasting effects on the climate, and was a key reason for end-Cretaceous mass extinction. [138] [139]
The dinosaur collections made over the past decade during the Hell Creek Project yielded new information from an improved genus-level collecting schema and robust data set that revealed relative dinosaur abundances that were unexpected, and ontogenetic age classes previously considered rare.
The Cretaceous is characterized by warm global temperatures caused by the high amounts of carbon dioxide and possibly methane greenhouse gases in the atmosphere. This caused a lack of permanent ice coverage in the polar regions, though the carbon dioxide level dropped between 115 and 66 million years ago (mya), possibly allowing some permanent ice cover.
Researchers have uncovered a "dinosaur highway" after hundreds of giant prehistoric footprints dating back 166 million years were found in an English quarry.
The author, Steve Brussatte, is a paleontologist at the University of Edinburgh. [1] A review in The Times described him as "a man who ranks as one of the leading experts in his field: a palaeontologist who seems to have studied with all the greats and to have dug up fossils everywhere that matters."
A 10-year-old found 220-million-year-old dinosaur tracks in Wales while fossil hunting.. Tegan Jones and her mother found the tracks, which hadn't been seen in over 140 years. An expert thinks a ...