Dinosaur Files

How long did it take for dinosaurs to become extinct?

I know the dinosaurs became extinct about 65 million years ago. What I'm wondering is how long it took them to disappear following whatever event began their decline - whether it was a meteor or some other event.

Public Comments

1. It is now apparent from the fossile evidence that extinction of life for the dinosaurs was relatively quick. Say on the order several weeks, or months at the lastest.
2. It deepends on what caused the extinsion. If it was a meteor crash, then it would meant that they would have been gone in about a year or so. Because of the large amount of dust which clouded the sky the dinos (who were cold blooded) did not recieve much heat so they started dying out. As they were large they could not hide increasing the loss of heat. Another reason which is said to be a cause of extinsion of dinosaurs is that the temperature increased due to which the male sex organs failed to fuction if this was the cause then it would have taken them years. About 50 years or so. But you can't be sure. ___________________________________________ Hope that helped.
3. I disagree with the above answers, and remain very sceptical about a meteorite impact being the SOLE reason for the extiction of the dinosaurs. If this were the case, then they should indeed have died out in a very short period of time of weeks or months. But even a period of 50 years is almost infinitessimally small in a geological time frame; and it should mean thea there is ONE fossil bed containing all the remaining dinosaurs (and whatever other life forms became extinct), and none above it. I do not know of any geological confirmation of this. Certainly, somethiung like that MAY have ocurred with the north American dinosaurs, close to the site of the supposed impact, but I think it was only one of a number of things that made it difficult (including climate change, volcanism, etc); so it may have taken some time for them to become extinct. What I can't understand is, if a meteorite was large enough to virtually instantly wipe out the dinosaurs on a global scale, how come the delicate, teeny mammals survived; and where did all the other reptiles that are still running around alive and kicking today come from? (And the birds for that matter, which are the living decsendants of the dinosaurs). I think it is a neat theory, and appeals to us on a science fiction sort of basis; but there are still a lot of holes in the idea to be plugged, in my opinion.
4. Not long!
5. One theory was a nuclear winter from off gassing of volcanoes as well. It is even a possability today. That a major volcanic eruption could spread enough ash into the atmosphere to blanket the planet for a good year in cold and darkness. Just one of many theories.
6. While the geological rock record shows relatively "quick" extinction, that could be in the realm of a few hundred years, not just days or months. Part of the problem, is it takes decades of sediments to form just a thin layer of sediment that becomes rocks today. And animals in the food chain did not die all at once, after global cooling started, due to a meteor hit on the Earth millions of years ago. I believe in the 4 Billion years of Earth history, there have been at least 4 "great extinctions".. Global cooling then caused reduction of plant life, that would first lead to extinction of the plant eaters, and much later the meat eaters. Larger animals requiring more food, would die off first. Smaller animals and reptiles would live the longest. Carnivors would continue to eat off the dying bodies of the plant eaters, the smallest would would be able to live longer. Evolutionary law, "survival of fittest" gave advantage to smaller species. . There is current scientific speculation, that modern birds evolved from dinasours. So, the "extinction" theories are being revised. Some species may not have disappeared, just evolved into smaller sized, adapting to new food supply, like insects, instead of meat. We know that crocodiles and aligators existed in the age of dinasours, and they did not go extinct, both meat eaters and they had a larger food supply from water life. Global cooling millions of years ago,also gave advantage to small mammals, from which primates evolved. Changes in natural environment are not always bad, some win, and some lose.
7. a month or two or even a few weeks. i rele want to see them!