8 August 2013
Everyone remembers the dinosaurs, but what happened after the dinosaurs went extinct? They left a vacuum filled by giant and often forgotten animals: the megafauna. The term megafauna, “big animals,” covers several groups of giant creatures. However, naturalist Richard Owen honored only the oldest members of the group with the special name, “dinosaur.” The remaining giants, those that roamed the earth between 10,000 and 40,000 years ago, are known by the (too general) term “megafauna.”
Today, Australia boasts a unique collection of animals. Not only do these creatures look exceptional, they are also exceptional in terms scientific classification. The duck billed platypus is classified as a mammal, but has a much lower body temperature than other mammals and lays eggs–earning it a special mention whenever biologists formulate a list of standard mammalian characteristics. Indeed, the platypus is so “different” that the first reports of its discovery were denounced as “a fraud.”
Australia, also, has a large variety of marsupials, a group of animals that carry their immature young in a pouch for a period of time after birth. Not surprisingly, the prehistoric Australian megafauna also include a wide variety of now-extinct marsupials.
Throughout millennia, arid periods threatened the survival of Australia’s megafauna, but one particular arid period, their last, coincided with the arrival of homo sapiens. There is intense debate about whether climate or human interference caused the extinction. Perhaps, it was some of both.
However, extinction is not necessarily the same as “dying out.” The megafauna are no more, but many of their direct descendants roam Australia today–miniature versions of their ancient ancestors. The modern kangaroo and wombat are direct descendants, “distant children,” of monstrously huge versions of themselves. And huge they were. New and more precise methods of calculating the size of the ancient mammals has revealed that they may have been much larger than previously thought.
Prehistoric Australia’s strange collection of giant wildlife included Diprotodon, the Giant Wombat. Unlike its relatively petite, modern descendant, this wombat weighed as much as two tons. The remains of these giant creatures have been found all over Australia.
The Giant Short-Faced Kangaroo, Procoptodon, the largest known kangaroo that ever existed, stood about 7 feet tall and weighed 500 pounds. Its feet looked a bit like horse hooves having only one large toe on each foot. Each of its front paws had two long fingers with large claws. A full-size, lifelike replica is on permanent display, along with other ancient Australian animals, at the Australian Museum.
The Marsupial Lion, Thylacoleo, was not quite as big as the modern lion, but had just as strong a bite. In fact, this creature had the strongest bite for its size of any known mammal species, living or dead. Its long muscular tail was similar to that of a kangaroo, and it may even have been able to climb trees. The Marsupial Lion is thought to have hunted large animals such as the giant wombat and giant kangaroo.
The Demon Duck of Doom, Bullockornis, is older than the typical megafauna species. Although living closer to the age of dinosaurs, it was just too unusual to omit. This flightless bird was about 8 feet tall and weighed about 500 pounds. Thought to be carnivorous, Bullockornis had a huge beak, suitable for “shearing,” which probably explains its threatening name.
The giant turtle, Meiolania, had disturbingly devilish horns making its head almost 2 feet wide (measured from the tip of each horn). The horns prevented the giant turtle from withdrawing its head into its shell–but who was going to mess with it anyway. Pulling its tail was not a good idea either. The tail was ringed with armor-like skin and was tipped with spikes. At about 8 feet long, most animals probably just got out of this turtle’s way as it crawled across the prehistoric landscape.
One cannot research these giant creatures without stumbling across the fact that all continents had megafauna–not just Australia. North America had one of the most famous species and one of the last to go extinct, the Wooly Mammoth. This enormous version of the modern elephant roamed the northern extremes of North America about 12,000 years ago.
At one-ton (2,000 pounds), Andrewsarchus was the largest carnivorous land mammal that ever lived. Bearing a resemblance to the hyena, on which it preyed, it might be the biggest dog-like creature that ever lived. It was certainly larger than the than biggest prehistoric dog, Canis Diris, the Dire Wolf. At 150 pounds, the Dire Wolf was a featherweight compared to Audrewsarchus, but more than a heavyweight compared to its descendant, the modern wolf. Remains of the Dire Wolf have been found alongside those of the Saber Toothed Tiger in the La Brea Tar Pits of Los Angeles.
Perhaps the species that suffered the most indignity at human hands was a giant version of the modern armadillo, Glyptodon. It lumbered through the forests of South America and was about the size of a modern VW bug. Slow and meaty, human hunters had both the patience and ingenuity to hunt and kill this strange creature. Not only was its meat used for food, its shell was used as a kind of prefabricated living shelter. In terms of size, its shell provided something like the Torrid Zone equivalent of an igloo. As human food and housing demands increased, the number of giant armadillos decreased until the prehistoric housing bubble burst when this natural producer of “prefabricated housing solutions” went extinct.
Selected Links & References:
Austrailian MegaFauna & Museums
Mega Fauna of the World & Museums
History and Continuing Study
Studying Megafauna Fossils: MelbourneMuseum
OZ fossils – The Age of the Megafauna – The Fauna – Fauna found at the Naracoorte Fossil site
Studying Megafauna Fossils: MelbourneMuseum
Art & Speculation
Other “Thursdays” about Animals: