The perfect gift for fashionable protozoans?
A 16-strong team of international boffins have added more evidence for the controversial theory that a gigantic asteroid smashed into the Earth 12,900 years ago and wiped out a range of furry mammals, including the mammoths. The researchers found an ancient layer of thin, dark sediment buried at the bottom of Lake Cuitzeo in …
in northern america is inconclusive and mastodons were still around 11000 years ago.
While it is possible an asteroid is responsible for some local mega-fauna extinction there seems to be a huge effort expended in avoiding pointing the finger at the one thing that consistently wipes out megafauna it cant ride once its out of Africa.
" why did they extinct the mammoths but not elephants?"
I would suggest that's simply due to the local environment and the availability of other food sources. One might just as well ask how Elephants and so on survived in Africa and Asia but wiped out everywhere else by this asteroid. It doesn't really make any sense.
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That's good news isn't it? Vaguely, anyway. It appears we get hit every 65 million years and one hit us 12,000 years ago. So we're safe then? Statistically, anyway :)
Frankly if we haven't worked out how to become independent of this ball of rock in 65 million years time we deserve to be wiped out.
The period was roughly 65M years -- not 65,000,002 or any other degree of precision. Stands to reason that if there are other big honking rocks out there in that cluster, that they may be ahead or behind the others, and so this could have just been a warmup for the big one. I wouldn't feel safe until we're a few million years past that period.
So if there was an impact event that recently, there should in theory still be a pretty big and reasonably fresh hole in the ground some place. Sure, the thing would be somewhat eroded and filled with plant life by now but it should be pretty obvious none the less, assuming it hit land. If it hit the ocean then there should be a nice smash mark on the ocean floor and a record of a mega tsunami in the ground around the coastlines about 12,900 years ago.
Really ? For a rock that's only several hundred meters wide, you expect it to plunge full speed through at least 3000 meters of increasingly dense water and only be stopped by the ocean floor ?
You've never done a belly flop before, have you ? You should try it. It'll give you some new respect for the resistance of water.