Mungo Man
A 60,000-year-old mystery

Bradshaws
The first civilisation?

Dreamtime
A time of creation

Megafauna Extinction
Fire and destruction

Cities
Why didn't Aborigines build cities?

Sex
Tribal reproduction

Aboriginal Culture?
60,000 years of continous culture?

The Extinction of Australian Megafauna

Today, wide-scale burning of the Amazon runs the risk of turning rainforest into savannah. In a rainforest, 50 per cent of rainfall gets recycled by the ecosystem. Rain falls, is trapped, sucked up by trees, released into the atmosphere, reaches a critical humidity and then falls again at a different location. When the land is cleared; however, not only does less recycling occur, less rain falls. The ecosystem then collapses forever.

50,000 years ago in Australia, large-scale burning of the land likewise turned rainforest into savannah, and then into desert. In 2004 and 2005, Dr John Magee and Dr Michael Gagana from the Australian National University showed that burning caused a decrease in the exchange of water vapour between the biosphere and atmosphere. Clouds stopped forming and the annual monsoon over central Australia failed. Whereas once the Nullarbor Plain was home to forests and tree dwelling kangaroos, now it is desert. Likewise, Lake Eyre, formerly a deep-water lake in Australia's interior, is now a huge salt flat occasionally covered by ephemeral floods.

As the rains failed, the Australia megafauna went extinct. The megafauna included wombats the size of hippos, three-meter-tall kangaroos, meat-eating ducks, marsupial lions, and seven-meter-long lizards. Some of the megafauna might have starved to death. The megafauna that didn't die would have become victims of starving humans that had quickly discovered that a land of plenty had become a land of empty.

The native animals that survived the ecosystem collapse were those that humans found difficult to hunt. The Kangaroo was one such animal. Although it congregates in groups, unlike a sheep or cow, the Kangaroo is not a herd animal. If a mob of Kangaroos is attacked, individuals run in different directions which makes them difficult to kill on mass. Humans soon adapted by using fire in hunting. With fire, a mob of Kangaroos could be herded towards a group of people waiting with spears. Unfortunately, the use of fire further contributed to the drying of Australia and continued the expansion of the desert. Eventually, eucalyptus forests, which recover quickly from fire damage, were all that remained in Australia. Koalas aside, eucalypts are not suitable for large browsing animals. A bountiful land of rainforests and large animals had become a land of desert, eucalyptus and small animals adept at avoiding humans.

Diprotodon

Weighing in at almost 2,700 kilograms, standing two meters tall and having a length of almost three meters, the Diprotodon was nearly 32 times as heavy as the Red Kangaroo; the largest marsupial alive today. It carried its young in a pouch, had wombat-like feet, and relatively long legs. It inhabited forests, woodlands, billabongs, and grassland where it grazed on all variety of vegetation.

The Diprotodon was probably preyed upon by Marsupial Lions, Humans, and Megalania.

Megalania

Some people believe that the myth of dragons was inspired by the discovery of dinosaur bones. Others believe it was inspired by the Komodo Dragon; a three-meter-long lizard living on the Indonesian island of Komodo. Although the Komodo Dragon is quite large, it doesn't intimidate people anywhere near as much as the Megalania once did.

The Megalania was a lizard roughly the size of a Crocodile. Weighing in at almost approximately 940 kg and growing up to seven meters in length, it was able to tackle three-meter-tall Kangaroos, Wombats the size of cars and perhaps ate the odd human for a bit of variety in its diet. It was an ambush predator that probably waited near water for passing prey.

Like the Komodo Dragon , the Megalania was very efficient in maximising energy from its kills. While some mammalian predators might leave behind 25 - 30 per cent of its prey, the Magalania consumed almost everything, including fur, feathers, and ones. Not only would it have consumed almost everything, very little would have been excreted. Whereas a mammalian predator excretes between 32-37 per cent of what it eats, the Megalania only excreted between 8-13 of what it ate.

Marsupial Lion (Thylacoleo carnifex)

Pound for pound, the Marsupial Lion had the most powerful bite of any mammal that has ever lived. It was capable of inflicting a bite three times more powerful than placental lions twice its size. Estimates about the weight of the Marsupial Lion have varied. It was roughly similar in length and height to a Leopard, but it was more robust. Some estimates have put its weight at between 112 and 143 kilograms, which is similar to an average Tiger. The Marsupial Lions hunting style was probably similar to a leopard. They had strong forearms, and retracting claws that made it possible for them to climb trees. There they would wait for an animal to walk beneath them.

Tribute to extinct megafauna

(Megalania) 

(Megafauna - animated)  

 
(Diprotodon)