Thylacoleo carnifex Click to enlarge image
The extinct marsupial lion Thylacoleo carnifex is the largest known carnivorous mammal in Australia. It was about the size of a leopard, at about 1.5 metres long and 75 cm tall at the shoulder. Thylacoleo was once widespread in Australia during the Pleistocene (1.6 million to 40,000 years ago). In 1871, Owen described this fossil jaw of Thylacoleo from Wellington Caves, which shows the specialised teeth for slicing flesh. It had enormous stabbing incisor teeth, enlarged premolar teeth that acted as long shearing blades, and very small molars. Thylacoleo possibly had the most powerful bite of any living or extinct mammal predator. Image: Abram Powell
© Australian Museum

During the Pleistocene (2.5 million to 11,700 years ago) the word had many examples of large animals that are collectively known as Megafauna. Australia was close to its current position, but sea levels were much lower. Humans may have first arrived in Australia during this time.

Australia's Pleistocene facts


  • Australia was very close to its present global position.
  • Sea levels fell, creating temporary land bridges between mainland Australia and Tasmania in the south, and Australia and New Guinea in the north.


  • Because of the waxing and waning of the polar icecaps, the climate in Australia continued to cycle rapidly between icehouse phases (cold, dry conditions) and greenhouse phases (warmer, wetter conditions.)
  • During icehouse phases sea levels fell, creating land bridges that would then be flooded during greenhouse phases.


  • Australia's plants were already well suited to dry conditions, but the pattern of forests, grasslands and deserts was constantly changing.


  • In Australia, the Pleistocene was the heyday of giant animals known as the Megafauna. They included the huge wombat-shaped Diprotodon and giant goanna Megalania.
  • The land connections created by the falling sea levels may have allowed humans to reach Australia from South East Asia at least 50,000 years ago.

What was happening in the rest of the world

  • European Megafauna included Woolly Rhinoceroses, Mammoths, Cave Lions and Cave Bears.
  • North American Megafauna included Giant Ground Sloths and Sabre-toothed Tigers.
  • African Megafauna included elephants, giraffes, rhinoceroses and hippopotamuses. Africa's Megafauna is all that remains around today.