The extinction of non-avian dinosaurs, which occurred approximately 66 million years ago at the end of the Cretaceous Period, was likely caused by a combination of factors, with the most significant being a large asteroid impact. This event, known as the Chicxulub impact, resulted in a global mass extinction, with around 75% of Earths animals, including dinosaurs, suddenly dying out.
The Chicxulub impact had immediate and long-term effects on the environment. The high-velocity impact of the asteroid vaporized it and created a massive crater, causing total devastation in the immediate area. A huge blast wave, heatwave, and the ejection of vast amounts of material into the atmosphere led to global changes in climate and atmospheric patterns.
In addition to the asteroid impact, other factors may have contributed to the extinction of dinosaurs:
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Volcanic activity: While recent research suggests that ancient volcanic eruptions, such as those in the Deccan Traps, did not directly cause the mass extinction event, their emissions of gases like sulfur dioxide and carbon dioxide may have weakened the ecosystem, making dinosaurs more susceptible to the effects of the asteroid impact.
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Disease: Some scientists speculate that disease, such as malaria carried by mosquitoes, may have played a role in the downfall of dinosaurs. A study by Oregon State University found that 65-million-year-old mosquitoes carried malaria, which could have killed off dinosaur populations.
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Long-term environmental changes: The continents were drifting and splitting apart during the late Cretaceous Period, creating larger oceans and changing ocean and atmosphere patterns around the world. These changes may have already been affecting the environment and could have made dinosaurs more vulnerable to the effects of the asteroid impact.
While the exact sequence of events and the relative importance of each factor are still the subject of scientific debate, the Chicxulub impact is widely considered to be the primary cause of the mass extinction event that led to the extinction of non-avian dinosaurs.
