the reason why dinosaurs was died out 65 million years ago

The extinction of the dinosaurs around 65 million years ago is attributed to various factors, with the most widely accepted theory being the impact of a massive asteroid or comet. Here's a brief overview:

1. Asteroid or Comet Impact:

   • A significant theory suggests that an asteroid or comet, estimated to be around 10 kilometers (6 miles) in diameter, struck the Earth near the present-day Yucatan Peninsula, resulting in the formation of the Chicxulub crater.
   • This impact would have released an enormous amount of energy, equivalent to billions of atomic bombs, causing catastrophic environmental changes such as:
     • Immediate fires and massive tsunamis.
     • Dust and debris thrown into the atmosphere, blocking sunlight and causing a "nuclear winter" effect, which would have drastically reduced photosynthesis, leading to the collapse of food chains.

2. Volcanic Activity:

   • Another contributing factor could have been massive volcanic eruptions that occurred around the same time, known as the Deccan Traps in present-day India.
   • These eruptions spanned over a million years but had a peak near the time of the extinction event, releasing huge amounts of sulfur dioxide and other gases into the atmosphere, which may have contributed to climate change and acid rain.

3. Climate Change:

   • Long-term changes in Earth's climate, possibly exacerbated by the impact and volcanic activity, could have altered habitats and food sources, making it difficult for dinosaurs to survive.

4. Ecosystem Disruption:

   • The impact and subsequent environmental changes would have caused a severe disruption in ecosystems. The loss of plant life due to reduced sunlight and the "nuclear winter" conditions would have impacted herbivorous dinosaurs, which in turn affected carnivorous dinosaurs that relied on them for food.

5. Other Theories:

   • There are other, less supported theories such as disease outbreaks, overhunting by contemporaneous mammals, or even a nearby supernova triggering increased cosmic radiation. However, these theories have less supporting evidence compared to the impact and volcanic activity theories.

It's important to note that the extinction event, known as the Cretaceous-Paleogene (K-Pg) extinction event, was not just limited to dinosaurs. Approximately 75% of all species on Earth, including marine life and various plant species, went extinct during this time.

While the exact sequence of events and their relative contributions to the extinction are still subjects of ongoing research, the asteroid or comet impact theory remains the leading explanation for the mass extinction event that marked the end of the Cretaceous period and led to the rise of mammals, including eventually, humans.