Question: why did the dinosours die?

Ceri-Wyn Thomas answered on 24 Jun 2010:

Ah my kind of question! OK here goes: there are multiple lines of evidence that give us an insight into ho the dinos died. First there’s evidence for an asteroid impact (I’m sure you know this). The site of the impact is thought to be at the end of the Yucatan Peninsula in Mexico. You can’t see it any more because in the 65 million years since it collided with Earth it has been infilled with lots of sediment and now it’s under the sea! We know it’s there though, through remote sensing techniques tat can identify different rock layers etc. There is also something called the Iridium Anomaly. Iridium is a metal in the same family as gold and platinum but on Earth t occurs in vastly tiny quantities. However, at the layer of rocks that existed on Earth’s surface when the asteroid hit- there is a thin line of rock chock’a’block with iridium! This is found all over North and South America in the same place in the rock record. Iridium occurs in abundance in asteroids! So another piece of compelling evidence.

At around the same time, an area of India known as the Deccan Traps was spewing out massive amounts of lava for a few million years!- more than your average volcano! This huge ejection of lava released so much ah and dust into the atmosphere- it probably blocked out the sun and killed off a lot of vegetation. So that, combined with the asteroid impact was probably enough to wipe out 65% of life on Earth! Not just the dinosaurs but many other marine organisms as well. Thank goodness we weren’t there! Most mass extinction events have more than one cause. It takes a lots to kill Life.