Ecosystem Changes Drove Extinction In Pleistocene Australia

Scientists may have finally established the explanation for the disappearance of the giant koala and other Australian megafauna.

Between 50,000 and 45,000 years ago, around 60 species of mammals, predominantly foraging herbivores called browsers, went extinct. These animals included 19 species that weighed over 100 kilograms, like the rhinoceros-sized giant wombat and half-ton marsupial Palorchestes azael. Slightly smaller animals like the flightless bird Genyornis newtoni were also mysteriously wiped out, according to a story published online in EARTH magazine.

While evidence of colonization has suggested humans were the cause of the animals’ disappearance, University of Colorado at Boulder geologist Gifford Miller and his fellow researchers think they have uncovered potential grounds for the megafauna’s disappearance: a change in the ecosystem that made their dietary staples no longer available.

The team’s research has been criticized for some of its finer technical points, but Miller told redOrbit they have the most comprehensive set of data available concerning the disappearance of these creatures.

For nearly two decades, Miller has collected bird eggshell fossils and marsupial teeth across the Australian Outback as part of the study. By analyzing these finds, the researchers have pieced together the ancient diets of three animals: Genyornis, along with the extant emu (another giant flightless bird) and the modern day wombat. They used these data to reconstruct the complex relationships among humans, vegetation, climate and animals on the continent over the last 140,000 years.

Source: redOrbit (http://s.tt/1dywX)