Timeline of Cretaceous–Paleogene extinction event research Hildebrand and William Boynton reported the Chicxulub crater in the Yucatan peninsula of Mexico as a probable impact site. While the controversy continued, the accumulating evidence gradually began to sway the scientific community toward the Alvarez hypothesis. In 2010, an international panel of researchers concluded that impact best explained the extinction event and that Chicxulub was indeed the resulting crater. Because the estimated date of the object's impact and the Cretaceous–Paleogene boundary (K–Pg boundary) coincide, there is now a scientific consensus that this impact was the Cretaceous–Paleogene extinction event which caused the death of most of the planet's non-avian dinosaurs
Iridium Alvarez proposed in 1980 an extraterrestrial origin for this iridium, attributing it to an asteroid or comet impact. Their theory, known as the Alvarez hypothesis, is now widely accepted to explain the extinction of the non-avian dinosaurs. A large buried impact crater structure with an estimated age of about 66 million years was later identified under what is now the Yucatán Peninsula (the Chicxulub crater). Dewey M. McLean and others argue that the iridium may have been of volcanic origin instead, because Earth's core is rich in iridium, and active volcanoes such as Piton de la Fournaise, in the island