Once upon a time, a 2-ton wombat lumbered across the Australian Outback. Around the same time, mammoths and saber-toothed tigers had the California coastline all to themselves. Millions of years before any of these animals existed, Tyrannosaurus rex and other colossal dinosaurs ruled the world.These and some of the other largest and most fantastic creatures ever to walk the planet are long gone, victims of mass extinctions of large beasts. And for reasons poorly understood, often the animals to fill the voids were tiny by comparison.Scientists generally accept that a giant asteroid slammed into the Gulf of Mexico some 65 million years ago, setting off a chain of catastrophic events that ultimately led to the extinction of dinosaurs. Whether or not an asteroid is to blame, the so-called KT boundary in the in fossil record displays a mass extinction of dinosaurs and other large animals around the world.Small scavenging mammals and birds survived the event, and scientists can't say for sure why dinosaurs did not.

Since bigger beasts couldn't take shelter in small protected burrows, perhaps they were done in by fierce environmental conditions. Or maybe with so many plants dying off, big herbivores simply had nothing to eat, and as they died out, so did the big carnivores. Or perhaps with all the stress, dinosaurs simply couldn't reproduce quickly enough to keep up with sexually nimble mammals and were soon outnumbered.

View: Full Article | Source: Live Science

Now the main thing about the large animals going extinct is because of lack of food supply. When Herbivores dye out it is because of the lack of vegetation, and the meat eaters when there is a lack of Herbivores. That is just nature.
But the main point about the Australian 2 Ton Wombat is, they disappeared 12,000 years ago because of the current burning off practices by Australian Aboriginals. Please do not tell me that it is because of global warming, as burning off all the natural landscapes causes global warming. Well after a few thousand years anyway, as they have done, it changed the Australian landsacape. I do not believe that all the Mega-marsupials where not killed off about the same time, but they did die about the same era approx 12000 years ago. When the local indigenous people where in full swing, the land of Australia was changed.
So go figure.

yeah I agree with harks, Large animals cannot adapt to environmental change as easily as smaller animals. simply because they grew large (and in this case grew a long thick coat) to adapt to the environment. and because the ice age was coming to an end, they could not adapt fast enough to the climate change, and also due to the already dwindling numbers of mammoth, human occupation didn't fair to well with the mammoths either (the hunting ect. mammoths were the largest herbavores, no predator dared attack them, only the young. and the mammoths didn't recognise humans as predators.)

there are quite a few smaller animals who are extinct as well..... every extinct species probably has its own circumstance for extinction...

(and i thought i read somewhere that they aren't so sure that the meteorite explosion wasn't neccessarily the cause of the mass dinosaur extinction.... or maybe i just made that up in my head)

And I was taught in school that the Aboriginals were 'better' at managing the environment than us, yet they managed to kill off more 'signicant' species in their time here than we could ever have killed off.

But it wasn't all due to burning off. The 'megafauna' were big, and they were slow - easy food for a small village of lazy hunters. Throw in a lackof knowledge about sustainabililty and you get a group of Natives eating a species in to extinction...



We should clone them and bring them back, evidence suggests that the last of them only died out a 200-1000yrs before we got here - if only someone had come here earlier and documented these great beasts before they were slaughtered.

Yes I am angry. I want megafauna!

Larger animals occupy a larger ecological niche...They need more food and water to sustain themselves...When a disaster strikes, they are more prone to them. They cannot support themselves because they need so much, and go extinct...The animals that were off to the side (mammals in the dinosaurs case) suddenly find themselves with a huge void in the ecosystem left...They quickly breed and evolve to fill that void...

This is also proof of punctuated evolution/equilibrium.