Dinosaur extinction

[bernardo]

It is always said that the dinosaurs became extinct 65 million years ago, but how precise is this figure? Is it known to the nearest million years? Or the nearest 5 million? Could it have been, say, 67 million? of 65.3 million?

[sft42]

From a vague memory of an interesting programme on the extinction of the buggers I think it was somewhere around the 250,000 years mark as the used the fossil record along with the magnetic shift of the earths poles to be able to date the rate of extinction.

[3s_a_crowd]

I have to suggest that yes, it could be, say, 10 million years out but in the scale of things that's probably like 1 grain of sand on Miami beach.
Second point relates to sft's answer. How did he sneak the word b*ggers into his post when you can't normally get the word cens.r (with an 'o' ) posted.

[FredPuli]

Can't say, but as you are there AB editor can't you correct the profanity cleaner-upper a bit? Why do we have to write 'female dog' for b****h, for example. ? Who in the world thinks the original word is profane or obscene ever?

[Quite enough people to make it worthy of being banned. The idea of the the profanity cleaner-upper being, of course, to prevent swear words appearing on what is hoped to be a family-friendly website. - AB Editor]

[gtrevor]

Is a crocodile a dinosaur and if it is why isn't it extinct?

[bernardo]

I reckon that crocodiles (and alligators, lizards, birds, ostriches, etc.) are dinosaurs really (or are descended from them. The reason we don't call crocodiles "dinosaurs" is because the word "dinosaur" has come to be understood as the subset of dinosaurs which got splatted 65m years ago. So the word "dinosaur" in its normal usage has a historical/sociological meaning as well as a biological/classification meaning. The only difficulty that I have with this theory is that we don't know for certain whether dinosaurs were warm-blooded (like birds) or cold-blooded (like reptiles).