When humans first traveled to what is now known as Queensland, they would have discovered massive animals such as goannas measuring six meters (20 feet) and kangaroos twice as tall as a human.
A team of researchers has analyzed the bones of these animals for the last ten years and published their studies in the journal Nature Communications, which shed new light on the mystery of what made these ancient megaanimals disappear.
Coexisting With Giant Animals
The first bones were discovered by the Barada Barna people while partaking cultural heritage surveys on their traditional lands approximately 100 kilometers (60 miles) west of Mackay, at South Walker Creek Mine. The research showcases the first reliable clue of the giants that lived in the Australian tropics between 40,000 and 60,000 years ago.
These megafauna were the most massive and animals to inhabit Australia since the period of the dinosaurs. While these animals lived at South Walker Creek, people had arrived on the land and were spreading across it. The new paper brings forth evidence to the ongoing megafauna extinction arguments but also highlights how much is left to understand from the fossil record.
The archaeologists unearthed fossils from four sites and performed detailed analyses of the sites to find the age of the bones and learn about the past environment. The findings somehow shaped an idea of how megafauna life was like in the tropical Australian savanna throughout a period of about 20,000 years. During this time, the northern megaanimals were different from those living in the south.
The Largest Kangaroo Ever Found
The team has found at least 13 extinct species at South Walker Creek, that had mega-reptiles as apex predators, and mega-mammals as their prey. Several species discovered are probably new groups or northern variations of their southern pairs.
Some, like the extinct crocodiles, were believed to have gone extinct long before people made their way to the continent. Still, they survived in at least one place, 60,000 to 40,000 years ago.
The mammals discovered were rather odd, such as a giant bucktoothed wombat, a peculiar bear-sloth marsupial, and massive kangaroos and wallabies. A kangaroo that has yet to be named is the most massive ever unearthed, with an estimated mass of 274 kilograms (600 pounds).
Environmental Change May Have Been the Culprit
It has been argued that the extinctions happened because of human over-hunting, and the event allegedly took place shortly after people arrived in Australia. However, this hypothesis is not backed up by the recent findings that a varied collection of these ancient giants still existed 40,000 years ago, after humans had spread around the place.
The extinction of this megafauna happened sometime after the youngest fossil site formed, approximately 40,000 years ago. The period of their disappearance took place at the same time with regional changed in water and vegetation. This mix of factors may have been lethal to the giant animals.
The megafauna extinction argument will definitely continue for years to come, but new findings will fill the key gaps in the record.