The impact crater was discovered in 1991. After that, it took several years to convince most scientists it was the cause. People had to write papers showing how the effects of the impact could cause extinction.

The volcano hypothesis remained around because of the Deccan traps which happened slightly before. However, many studies have shown that the climate change caused by the volcanism was small (loss of 2°C which is negligible compared to the variation of temperature that happened during the hundreds of millions of years the dinosaurs lasted) and that the dinosaurs survived during the time between the start of the Deccan trap volcanism and the impact.