- David Norman
‘The future of research on the past’ outlines how our account of dinosaur extinction has developed. The reign of dinosaurs came to a very abrupt end 65 million years ago. Why? Theories ranged from the elegant to the outlandish, until Walter Alvarez — the palaeobiologist son of an astronomer — examined the levels of cosmic dust in the Earth's crust. He found evidence of a massive meteorite collision. This would have generated a dust cloud so big it would have strangled all plant life and caused mass extinction. Current research appears to show that a series of meteorite collisions and other phenomena ultimately ended the age of the dinosaurs.