Dinosaurs became extinct primarily due to the catastrophic impact of a massive asteroid about 66 million years ago. This event created the Chicxulub crater off the coast of Mexico and caused immediate devastation locally and widespread environmental effects globally. The impact released dust, vaporized rock, and gases into the atmosphere, blocking sunlight and disrupting photosynthesis, which led to a collapse in food chains both on land and in the oceans. This sudden environmental catastrophe ended the reign of dinosaurs that had lasted about 180 million years

. In addition to the asteroid impact, other factors likely contributed to the extinction. These include massive volcanic eruptions in the Deccan Traps region of India, which released large amounts of dust, sulfur aerosols, and greenhouse gases like carbon dioxide. These volcanic activities caused long- term climate changes such as global warming and acid rain, which further stressed ecosystems. Some scientists suggest that these volcanic effects combined with the asteroid impact to cause the mass extinction

. Other hypotheses, such as disease epidemics or supernova radiation, have been proposed but lack the strong evidence supporting the asteroid impact and volcanism theories

. In summary, the extinction of non-avian dinosaurs was mainly triggered by the asteroid impact that caused a global environmental crisis, with volcanic activity and gradual climate changes likely playing significant supporting roles