What Australia would have looked like when the dinosaurs roamed

An artist's impression of a hungry Australovenator pursuing a pair of Leaellynasaura. (Supplied: Museums Victoria) Link copiedShareShare articleIt is 100 million years ago, parts of Australia are in the Antarctic Circle and dinosaurs roam a polar world. Swift, 5-metre-long predators like Australovenator hunted during months of darkness. Meanwhile, herds of Leaellynasaura fed among ferns covered in frost. That's the picture painted by palaeontologists, who have found evidence of Australia's dinosaur history dating back when the continent was still attached to Antarctica. Dinosaur Cove is west of Cape Otway. (Supplied: Tom Rich) In the early Cretaceous Period, Australia was a very different place. There was a vast river cutting through a rift valley and, along either bank, a temperate rainforest. This forest would have been teeming with dinosaurs, Monash University palaeontologist Jake Kotevski said. Monash University palaeontologist Jake Kotevski. (Supplied: Jake Kotevski) "We find a lot of dinosaur material (around Australia)," Mr Kotevski explained. "You don't get a lot of complete individual animals, but we get lots of bits that hint at a substantial population of dinosaurs across a long period of time. "We also get a ton of footprints across Victoria. The most common ones we see include ornithopods — these little bipedal herbivores which get to the size of a wallaby." Mr Kotevski compared dinosaur populations in south-eastern Australia to kangaroo mobs which mass across modern-day Victoria or emus that roam southern Queensland. The evidence is gathered from sites like the "Dinosaur Dreaming" project near Inverloch on Victoria's Bass Coast and Lightning Ridge in north central New South Wales. Jake Kotevski says many fossils are found around coastal Victoria. (supplied: Jake Kotevski) Despite popular dinosaur mythology, giant dinosaurs are comparatively rare finds. "We had a dig in February (in Victoria) and pulled out a tiny jaw of barely a centimetre," Mr Kotevski said. "It's a herbivorous dinosaur that's whole skull was probably only a couple centimetres. "The whole animal was maybe 30 centimetres or so in length and it's probably a juvenile." Apart from the swift megaraptors, there would have been 3-metre long proto-Tyrannosauroids like Timimus (Tyrannosauroids did not grow huge until towards the end of the Cretaceous age), along with other large predatory animals that were not dinosaurs at all. Earth's polar regions during the Cretaceous Period, including the continental shard that would become Australia, did not resemble today's frozen Antarctic wasteland. There would have been areas of local ice, glaciers and mean temperatures as low as minus 6 degrees Celsius. The dinosaurs which lived there would have had to deal with between three and four months of continuous darkness, according to Museums Victoria palaeontologist Dr Tom Rich. Husband and wife palaeontologists Dr Tom Rich and Dr Patricia Vickers-Rich. (Supplied: Tom Rich) "In Australia, we have a span in the Victorian sites of about 15 million years between the oldest and the youngest dinosaurs," Dr Rich said. "The oldest, which are along the Bass Coast, shows evidence of rather cold conditions, including permafrost. "The younger deposits, which are in the Otways, the evidence of really cold conditions is no longer there." Animals which died out elsewhere in the world, as the climate warmed, persisted in polar Australia. These included strange amphibians called temnospondyls, which look like crocodiles. "They're amphibians, not reptiles," Dr Rich said. "They appeared about 350 million years ago and flourished until about 200 million years ago. Then they dribble out for about another 10 or 20 million years and they're gone, except in Victoria. "That was one of the biggest surprises when we found them, this group that was thought to have gone extinct about 20 million years earlier. These amphibians may have been very happy in cold environments." Evidence of Australia's polar dinosaur past was first discovered in 1903. However, it was not until the late 1970s that Australia became an international palaeontological hotspot. The teams which excavated sites along the south-eastern coastline included Dr Rich and Patricia Vickers-Rich, who migrated from the United States to uncover these newly discovered dinosaurs, along with future palaeontology stars John Long and Tim Flannery. Dr Rich and Dr Vickers-Rich ultimately dubbed a previously unnamed Otway Coast location "Dinosaur Cove" in 1984. About 70 volunteers, aged between seven and 77, according to Dr Rich, found scores of fossilised dinosaur bones there. Palaeontologists and volunteers digging for fossils at Dinosaur Cove. (Supplied: Tom Rich ) More than 700 volunteers have since been involved across multiple sites, Dr Rich said. Compared with other dig sites around the world, Australian dinosaur fossils are especially difficult to uncover because much of the e

What Australia would have looked like when the dinosaurs roamed

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