What is the most scientific support of the extinction of dinosaurs?

The most scientific support for the extinction of dinosaurs is the evidence of a massive asteroid impact, particularly the Chicxulub crater in Mexico, which dates to around 66 million years ago. This impact would have caused widespread fires, tsunamis, and a "nuclear winter" effect, leading to drastic climate changes that disrupted ecosystems. Additionally, geological evidence shows a significant layer of iridium-rich clay, known as the Cretaceous-Paleogene boundary, marking the extinction event. Other factors, such as volcanic activity and changing sea levels, may have also contributed to the extinction.