The atlatl dart thrower was the prehistoric M16 or AK47
There's an excellent thread about the atlatl earlier on this forum but I'll start a new one.
There's a wealth of information on the atlatl dart-thrower on the Internet so I won't duplicate all that information. Suffice to say, the atlatl (pronounced either, 'addle-addle', or, 'at-lattel') was the prehistoric M16 or AK47 of its time. I'm not that far from exaggerating. The atlatl helped put prehistoric man at the top of the food chain.
For starters, to be technical about it, the atlatl is not a spear-thrower. It's a 'dart' thrower. Imagine a thick, feathered arrow, 3/8th's thick, with a much larger point, and six to seven feet long. This 'dart', would flex with springing motion when tossed overhand with the atlatl thrower. The flexing of the dart would impart a spring action, helping to propel the dart as far as 200 meters. Because of the length, size, and weight of the dart, it had tremendous penetration power. For the first time, the magnificient Columbian Mammoth and the iconic Ice Age Woolly Mammoth became vulnerable to coordinated human hunting parties.
The atlatl preceeded the bow and arrow by as little as 15,000 years, possibly as much as 30,000 years. But the more compact, portable bow proved more efficient to use, despite the bow's arrow being smaller with less penetration and damage. The atlatl would nearly disppear from worldwide usage, except in Australia and some Inuit eskimo use. The Aztecs re-discovered the atlatl technology and later used it against the Spanish conquistadors.
Standing off, say, 50 meters or so, and striking a bison with atlatl darts from several prehistoric hunters, proved more effective and safer than Neanderthal man's presumed hunting technique of ambushing large prey mammals by jumping on their backs and trying to spear the animals at point blank range.
Paleontogoists are not all in agreement but a popular theory is that prehistoric man, armed with his deadly killing atlatl, confronted the large mammals of his time era, already in decline because of the climatic chaos caused by the ending Ice Age. Prehistoric man alone couldn't have sent those magnicient gigantic mammals to their extinction, but he may have helped them along with his atlatl. Thus became the dodo birds of their time: the mammoths, the sabre tooth cats, the towering short-faced bear, the North American lion, dire wolves, the gigantic beaver, North American ground sloth (the size of a T-Rex).