Mass Extinction of Giant Beasts

Peter Lewis talked to Bishopsteignton Probus Club about the mass extinction of North American “mega fauna” (giant beasts).   He started by saying that mass extinctions come from outer space, such as the great meteorite that killed off the dinosaurs 65 million years ago.  He showed pictures of various extinct beasts, including the mammoth (picture attached) and many other beasts which were much larger than animals still on earth today, including the sabre-toothed cat, American lions and giant ground sloths, which were as tall as a giraffe and of a similar build to an elephant.   A relative of the modern rhinoceros was the largest land animal ever to have lived, weighing in excess of 17,000 pounds.

Peter outlined three theories which people have put forwards to explain the extinction of these giant beasts.    The first idea was that humans had driven them to extinction by hunting and killing them with flint spears.   There is very limited evidence to support this theory and he pointed out that hunter gatherers never exterminated their prey because to kill them all would be senseless.

Club members were told that Milutin Milankovic, born in 1878, identified three cycles of the earth’s movement in space.  These cycles increase or decrease the heat earth receives from the sun and every 100,000 years or so the earth is in an ice age.  This was dismissed as a possible cause because none of the previous 23 ice ages during the last 2.5 million years had produced mass extinctions.

Peter Lewis’ belief is that the giant beasts were destroyed thousands of years ago when asteroids impacted on North America.  When they struck across America from Northern Greenland to Lake Huron, they made 35-kilometre-wide craters with explosions that were thousands of times more powerful than the Hiroshima bomb.

Picture of one of the extinct giant beasts – A mammoth