The remains were discovered by Mr. H.B. Wade on Clutha Station near Maxwelton in north Queensland in 1932, who alerted the station manager H. Mackillop, who showed his brother who sent them to the Queensland Museum. Austrosaurus was described by Heber Longman in 1933.
- A. mackillopi
- A. sp. ("Elliot")
In 1999 on a property near Winton in central-western Queensland, Australia, grazier Dave Elliott found a sauropod femur belonging to what turned out to be the largest dinosaur discovered in Australia to that date, which was nicknamed 'Elliot'. At the Winton find, a right femur and portions of several ribs have so far been uncovered. A smaller sauropod, nicknamed 'Mary', after Dr Mary Wade, has also been uncovered. Early indications are that they are closely related to Austrosaurus mackillopi and either in the same or closely related genus.
On 3 May 2007, bones from the remains of two huge titanosaurs which were uncovered in 2004 near Eromanga in south-west Queensland went on display at the Queensland Museum, in Brisbane. This find was described by the ABC news service as the largest bones now discovered to date in Australia, eclipsing 'Elliot'. Originally it was thought that sauropods spent time near or in water to relieve weight from their legs. However, this theory is now rejected and it is believed that Austrosaurus like all sauropods lived on dry land. Fossil finds suggest a height of approximately 3.9 metres at the hip and 4.1 metres at the shoulder, which would have given it an almost level back. Initially, Austrosaurus was considered a cetiosaurid, like Patagosaurus or Shunosaurus. However, a recent reappraisal of material by Ralph Molnar has found that it, and the newer remains of 'Eliot', are titanosaurid, as various features on the vertebrae show.