Gondwana began to break up in the Early Jurassic (about 184 Mya) accompanied by massive eruptions of basalt lava, as East Gondwana, comprising Antarctica, Madagascar, India and Australia, began to separate from Africa. South America began to drift slowly westward from Africa as the South Atlantic Ocean opened, beginning about 130 Mya during the Early Cretaceous.

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There is more evidence of dinosaurs in Australia from the Jurassic period than from the Triassic period. A partial skeleton of a large sauropod called Rhoetosaurus brownei was discovered in south-east Queensland. Rhoetosaurus was one of the oldest-known sauropods, existing around 170 million years ago. It was 12 metres long. Like other sauropods, it had a long neck, but its neck was not quite as long as that of Brachiosaurus. This may be because Rhoetosaurus was at an earlier stage of its evolution than Brachiosaurus. Smaller dinosaurs lived in Australia as well as larger ones like Rhoetosaurus and Allosaurus. Evidence exists for a small ornithopod dinosaur with a length of only one to two metres. This dinosaur fed on plants and its footprints have been found in central Queensland. Rhoetosaurus, and so for a long time, it was called a cetiosaurid. But this group is now simply considered an unnatural grab-bag of basal (primitive) sauropods. More recently, others have compared it to Shunosaurus, based on similar general age, but without justification supposed a clubbed tail.

Back to the Jurassic or Next to the Early Cretaceous Australia.