Dinosaur extinction has caused plenty of arguments in paleontology. Over one hundred ideas and hypotheses have been discussed. Some of them were impossible to prove, like what if strange, new plants didn't agree with dinosaur gutscausing all the dinosaurs to fill with gas and explode.
Another idea was that mammals ate all the dinosaur eggs. That's another one that's hard to prove, but we can say that so far no mammal has been found in a dinosaur nest. No dinosaur eggs - drained of their contents - have been found with mammal teeth marks. It's not impossible, but so far, no evidence. If we did find evidence like this, the next question for scientists would be: What would have caused those mammals to suddenly change their diets to dinosaur eggs only?
There's one hypothesis that many scientists think has the most evidence. It would explain why everybody who weighed more than one hundred pounds died. The Chicxulub (pronounced CHICK-sha-lube) crater is half in and half out of the Gulf of Mexico, in the Yucatan Peninsula. It's 110 miles across, and would have been formed when an asteroid collided with Earth. This means a six-mile-wide Cosmic Cannonball plowed into Earth at 40,000 miles per hour, driving seven or eight miles deep into the Earth's crust. It was so big that when it first touched down, its nose was in the dirt, and its rear end was still out in spaceoutside our atmosphere.
The impact turned the Cannonball into pure energy and spit out all kinds of heat, molten rock, dust, and debris. Scientists have found debris splattered from Mexico to Texas to Haiti to Cuba, and preserved asteroid dust all over what were then all the oceans and on what was then the land in North America. The explosion would have been 50 billion times larger than the atomic bomb that destroyed Hiroshima, Japan, during World War II.
After such a tremendous blast, the sky was black with smoke and dust, and the sun didn't reach the earth for perhaps a year or more. There were earthquakes and forest fires, acid rain and giant tsunamis. Plants died, plant-eaters died, and then predators died. We think that the only creatures that could live through this were animals that didn't have to eat very often, like crocodiles, or small creatures who could find shelter and live off dried plants, buried roots, and the carcasses of everybody elselike small mammals and birds.
When everything calmed down again, and the sun came back out, and plants began to grow, there were no large dinosaurs left. This allowed mammals to grow larger than rats and catswhich were the largest mammals got during the 160-million-year reign of the dinosaurs. This made room for us.