Dinosaurs went out with a bang, says study

The dinosaurs died out as a result of a huge asteroid strike rather than the eruption of a super volcano, according to a study published today in the journal Science . Dr Paul Bown (UCL Earth Sciences) was part of a panel of researchers who analysed more than two decades? worth of evidence to determine the cause of the Cretaceous?Tertiary (KT) mass extinction. The KT extinction, which happened around 65 million years ago, wiped out more than half the species on Earth, including the dinosaurs, pterosaurs and large marine reptiles, clearing the way for mammals to become the dominant species. This study of all the available evidence concludes that the KT extinction was caused by an asteroid slamming into the planet at Chicxulub in Mexico with a force one billion times more powerful than the atomic bomb at Hiroshima. The asteroid ? about the size of the Isle of Wight ? would have blasted material into the atmosphere at high velocity, triggering a chain of events that caused a global winter, wiping out much of life on Earth in a matter of days. Some scientists have argued that the KT extinction was caused by volcanic activity in the Deccan Traps in India, where a series of eruptions lasted approximately 1.5 million years. These eruptions spewed 1,100,000 cubic kilometres of basalt lava across the Deccan Traps, which would have been enough to fill the Black Sea twice, and caused a cooling of the atmosphere and acid rain on a global scale.