Letter: Dinosaurs' demise

Sir: The demise of the dinosaurs ("Dinosaurs were wiped out in giant firestorm when meteor ignited methane", 16 November) should not be viewed as caused by a single event. The favoured hypothesis amongst Earth scientists is that the mass extinction of 65 million years ago was a result of a combination of factors, including global cooling, continental drift, volcanic activity and atmospheric change, which interacted over several million years. The Mexico meteorite may have been the last in a series of ill winds that finally "snuffed out the candle".