Australia: The Land Where Time Began

A biography of the Australian continent 

The First Settlers in Australia - What They Found

At the time the first settlers arrived in Australia it was inhabited by a marsupial megafauna, just as the other continents were inhabited by a placental megafauna. Many of the marsupial megafauna had become extinct by the time of European colonisation of Australia, though some marsupials and birds, such as the red kangaroo and the emu have survived until the present, though they are smaller than their megafauna ancestors, though Genyornis was not ancestral to emus. Even coming across these non-carnivore animals of the megafauna for the first time must have been terrifying to the first settlers. The megafauna ancestor of the red kangaroo, Macropus giganteus titan, weighed about 200 kg, compared to about 60 kg for a red kangaroo, and stood hip to shoulder with a human, reaching a height of almost 3 m.

Another marsupial that was similar to a kangaroo was Procoptodon goliah, 1 of 17 species of Sthenurines inhabiting open woodlands in northern Australia. Another species of Sthenurine was Simosthenurus occidentalis, a heavily built wallaby-like animal that weighed about 200 kg and, as with Procoptodon, had distinctive feet with a large 4th toe and side toes that were greatly reduced. It seems they probably inhabited the drier parts of Australia, browsing on chenopods, saltbush and bluebush (10).

Euros, or wallaroos, that were 20 % larger among the megafauna than they are at present, and the giant rat-kangaroos, Propleopus, that was about the size of a female grey kangaroo, that weighed about 40 kg.  Propleopus inhabited eastern Australia and appears to have fed on insects, nuts and fruit, and also small marsupials and eggs, probably filling the niche filled by small bears on other continents, being their marsupial equivalent in that sense. The was also Zaglossus, the long-nosed echidna weighing 30 kg, and Meiolania, a terrestrial turtle, that was as big as a VW car weighing 200 kg that had feet like an elephant. It was unable to retract its head but 2 long horns projecting from its skull would have been a form of protection, and its armoured tail terminated in a bony club covered with blunt spikes (11).

Phascolonus, a giant wombat, that was also a part of the megafauna was 8 times the size of the wombat of the present, weighing as much as 500 kg and dug burrows that are large enough for humans to walk into when stooping, which would probably have made them easy prey for the first humans to encounter them. Diprotodon was a wombat-like marsupial that was a mixed feeder inhabiting preferably semi-arid lands in all parts of Australia. About the size of a hippopotamus that weighed more than 2,500 kg, and had pillar-like legs and was about 4 m long, about 1 m of which was a large, heavy head with large bony projections on its face that are suggested to have supported a nose pad like that of a koala. An unusual feature of the skull is that the back of the skull was wafer thin and hollow inside, possibly to make the large head lighter while providing bone to which muscles could be attached to operate the large jaws. It had a very small braincase, an indication it was a slow animal, and probably wasn't very intelligent, which together with the thin skull bone possibly made it an easy target for human hunters.

Zygomaturus, another unusual animal, often called the marsupial rhinoceros, that weighed 0.5 tonne, was about 2 m long, was about 1 m high at the shoulder, about the height of a bullock. It had the body shape of a Diprotodon, though it had a different head. Its face had a pinched appearance and it had a steep forehead, and its eyes faced forward, and there was a patch of bone that was roughened on either side of the nose that could have supported horns. It has been suggested Zygomaturus inhabited wetlands, where it scooped up rushes and sedges with 2 fork-like incisors.

Palorchestes was another unusual animal. It was about the size of a bull, walked on 4 legs and had a short trunk, similar to that of a tapir. Its forearms were massive and incredibly strong, and it had long, sharp claws, 10 cm long. The joints of its elbows locked in a semiflexed position, its overall anatomical composite indicating it was a giant sloth-like animal that was compact and hugely strong and almost mechanical in the ability it had to fell trees and strip branches for food. The tongue of the animal is indicated by the morphology of its jaw to have been long and slender which suggests it may also have eaten insects. These giant marsupials are generally believed to not have been dangerous to humans, though an animal that felt threatened could be expected to dangerous on account of its massive size.

There were also carnivores, some of which were not a threat, such as the Tasmanian tiger (Thylacinus cynocephalus) and the Tasmanian devil, that were both present throughout the continent at that time, they were hunters and scavengers that hunted small prey. Other carnivores at the time were not so harmless. The top marsupial predator was the 'marsupial lion' (Thylacoleo carnifex), that was about the size of a leopard and is believed to have lived in trees. This was a strong animal that is believed to have been slow and had claws that seem to have been adapted for climbing, ripping and pulling, characteristic that have suggested it hunted from the trees, dropping down on its prey from the trees. It is believed that it dragged its prey into a tree before it started eating, as leopards do at the present. Its teeth were designed for piercing, stabbing and slicing. It was widely distributed, the author¹ suggesting it may have had a hunting territory of as much as 100 km².

The first dangerous predators the settlers would have encountered on arriving in Australia would have included some they knew from their homes along the coasts and estuaries of Indonesia such as crocodiles, though they may not have expected the size of the enormous riverine crocodile Pallimnarchus, as well as a smaller relative, Quinkana, that is believed to have been a terrestrial crocodile, as well as the extant 3-m freshwater crocodile and the 5-m saltwater crocodiles. The remains of Quinkana have been found in cave deposits associated with other terrestrial animals far from the nearest water. Its weight has been estimated as about 200 kg. Its blade-like serrated teeth resembled those of a carnivorous dinosaur. Its feet were hoof-like instead of being webbed as is the case in other crocodiles, and its legs were disproportionally long, suggesting it could run fast. It is believed its hunting method was as an ambush predator, which would make life in this new country one of constant vigilance. No doubt Pallimnarchus would have added to the precarious survival of the first human inhabitants. It was a very large animal of the size of the largest of the living saltwater crocodiles (salties) of the present. It had a broad, short snout, and its prey is believed to have been mammals feeding at the edge of the water. These large crocodiles inhabited the entire continent through the vast catchment between northern Australia and Lake Eyre. Crocodiles could potentially move from the southern parts of central Australia to the Gulf of Carpentaria and the Arafura Sea.

And there were many snakes, some of which were as they are at the present, on riverbanks and around waterholes, as well as some that are now extinct. Wonambi was one of these extinct snakes that weighed about 50 kg, it lived in southern Australia. It grew to at least 5 m and was 30 cm in diameter, and its broad flat, head was as broad as a shovel. A giant snake, it was possibly a constrictor, it had hundreds of tiny teeth, but as it may not have been capable of disarticulating jaws, it may have been more a biter than a constrictor. It has been suggested that it may have been an aquatic snake that fed on fish and other water-borne prey, or possibly an ambush predator that waited beside waterholes, or in rocky areas, beside animal pathways. It is suggested to have also lived away from water as its remains have been found in southern Australian cave deposits together with other faunal remains. It has been suggested that the caves provided ambient temperature and adequate shelter for survival, a case of giant caves for giant snakes; at the present snakes live in rabbit burrows.

In ancient Australia there was also a giant lizard, Megalania prisca, that grew up to 7 m long and weighed almost 2 tonnes. Its body was bulky and it had a short neck and a thick tail, and it had curved, chunky teeth, serrated on 1 side like a steak knife. It is a relative of the Komodo dragon, a pack hunter that hamstrings and eviscerates its prey. The Komodo dragon can run at up to 20 km/hr.

["It was formerly believed Komodo dragons weakened their prey by biting them which allowed particularly virulent bacteria to get into their blood stream so that they quickly weakened allowing the dragons to track them by their scent trail and attack them when they were too weak to resist or escape. It is now known that, as has been found with goannas, Australian lace monitor lizards, the closest living relative of Komodo dragons, they actually have venom glands running along the inside of their jaws that are squeezed when they bite allowing the venom to trickle into the wound, though they have no specialised fangs to inject the venom into the prey." MHM]. See Australian Reptiles

According to the author¹ he has seen a few Aboriginal people try to outrun a perentie goanna but none have succeeded, and he suggests that it would probably be even harder to outrun a hungry Megalania. It has been suggested Megalania were capable of hunting the huge Diprotodon, so they would have no problem hunting humans. They are believed to have had a population density of 1 per 200 km². They tended to favour aquatic habitats where they could lie in wait in the high grass of a tropical savannah for an unwary prey species to come close enough for a quick dash, if it could bite the prey it could let it go then tack it until it was too weak to put up a struggle, as Komodo dragons do.

 Sources & Further reading

1. Cane, Scott, 2013, First Footprints: The epic story of the first Australians, Allen & Unwin