Rhoetosaurus

Rhoetosaurus (meaning "Rhoetos lizard"), named after Rhoetus, a titan in Greek Mythology, is a genus of sauropod dinosaur from the Jurassic (?Middle Jurassic) of what is now eastern Australia. Rhoetosaurus is estimated to have been about 12–15 metres long. Subsequent authors have sometimes misspelled the name: Rhaetosaurus (de Lapparent & Laverat, 1955); Rheteosaurus (Yadagiri, Prasad & Satsangi, 1979).

Discovery and species
1924, Heber Longman, self-trained paleontologist at (and later director of) the Queensland Museum in Brisbane, learned of a large fossil reptile skeleton exposed at the Durham Downs Station near Roma in central Queensland. The station manager, Arthur Browne, forwarded fragments of bone to Longman, and was honoured with the dinosaur's specific name brownei.

The initial collection was of 22 tail vertebrae, including a series of 16 consecutive bones, and other fragmentary hindlimb pieces. Soon after Longman announced the new discovery, he visited the station and arranged for more material of the same skeleton to be sent to the Queensland Museum. These included additional vertebrae from the thoracic area, bits of rib, more caudals and more of the femur and pelvis as well as a cervical vertebra.

Further material was collected by Mary Wade and Alan Bartholomai in 1975, and still more by Drs. Tom Rich, Anne Warren, Zhao Xijin, and Ralph Molnar. This additional material includes more ribs, another possible cervical vertebrae, and most of right hind limb, which is currently under study. To date, the end of the tail, forelimbs, and skull have not been found.

Rhoetosaurus is among the best-known sauropods thus far discovered in Australia, as well as for the Jurassic of Gondwana.

Relationships
Initially Longman, with advice from leading German paleontologist Friedrich von Huene, noted the primitive nature of 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. Given its supposed relationship to Shunosaurus, which had a clubbed tail, Rhoetosaurus has also been hypothesized to possess something similar. The form of the nearly complete hind foot ([1])at least suggests that lies outside the more derived Neosauropoda, but the material needs further study to determine its precise positioning in sauropod evolution.