Did a mega impact kill off the dinosaurs?
It’s believed that 65.5 million years ago Earth may have been struck by a number of massive asteroids whose impacts triggered the K-T (Cretaceous–Tertiary) global extinction event thought to have wiped out around 80 per cent of Earth’s animal and plant species – most notably all the non-avian dinosaurs.
As well as the immediate annihilation caused by such an asteroid impact, other fatal consequences include wildfires ignited by the burning rock, kilometre-high mega-tsunamis triggered by the shockwaves, global clouds of dust and other ejecta capable of blocking out the Sun for a decade, as well as endless other knock-on effects from the strike.
Evidence that supports the asteroid theory includes the discovery of the 180-kilometre (111-mile)-wide Chicxulub Crater in Mexico’s Yucatán Peninsula. What’s amazing about Chicxulub is that it’s not actually visible above ground; its structure lies almost a kilometre (0.6 miles) below today’s surface. The crater was only discovered in the Seventies by people prospecting for oil.