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Full Version: Ancient Australians coexisted with 3-tonne marsupials & lizards longer than thought
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https://theconversation.com/humans-coexi...lia-138534

EXCERPT: When people first arrived in what is now Queensland, they would have found the land inhabited by massive animals [...] We have studied fossil bones of these animals for the past decade. Our findings, published today in Nature Communications, shed new light on the mystery of what drove these ancient megafauna to extinction.

[..] Imagine first sighting a six-metre goanna and its Komodo Dragon-sized relative, or bumping into a land-dwelling crocodile and its plate-mail armoured aquatic cousin. The mammals were equally bizarre, including a giant bucktoothed wombat, a strange “bear-sloth” marsupial, and enormous kangaroos and wallabies.

A yet-to-be named giant kangaroo is the largest ever found. With an estimated mass of 274 kg, it beats the previous contender, the goliath short-faced kangaroo, Procoptodon goliah. The biggest of all the mammals was the three-tonne marsupial Diprotodon, and the deadliest was the pouched predator Thylacoleo. Living alongside these giants were other megafauna species that still survive today: the emu, the red kangaroo and the saltwater crocodile.

[...] Why did these megafauna become extinct? It has been argued that the extinctions were due to over-hunting by humans, and occurred shortly after people arrived in Australia. However, this theory is not supported by our finding that a diverse collection of these ancient giants still survived 40,000 years ago, after humans had spread around the continent.

The extinctions of these tropical megafauna occurred sometime after our youngest fossil site formed, around 40,000 years ago. The timeframe of their disappearance coincided with sustained regional changes in available water and vegetation, as well as increased fire frequency. This combination of factors may have proven fatal to the giant land and aquatic species.

The megafauna extinction debate will no doubt continue for years to come. New discoveries will plug up the key gaps in the record. With the gaps in the north of the continent the greatest yet to fill. With an overlap between people and megafauna of some 15,000–20,000 years, new questions arise about co-habitation. How did people live with these giants during a period of such drastic environmental change? (MORE - details)