South African palaeontologists today announced the discovery of a new species of "transition" dinosaur that straddles the divide between the four-legged giant herbivorous sauropods and their mainly bipedal predecessors, according to dpa. The Aardonyx Celestae, as the new dinosaur has been named, was discovered on a farm in central Free State province in the Karoo Basin, an area rich in fossils. "What we have here in Aardonyx is an intermediary dinosaur. It"s not entirely a prosauropod and it"s not a sauropod," palaeontologist Adam Yates said, unveiling the fossil remains at the University of the Witwatersrand in Johannesburg. The dinosaur roamed the area between 183 million and 200 million years ago, measured between 7 and 9 metres long and was "probably the weight of a horse," he said. The specimen was a juvenile, which was aged between 7 and 10 years. Aardonyx dates to the early Jurassic period and has many features of the sauropod - the huge, lumbering dinosaurs with the small heads, long necks and elephantine legs popularly known as brontosaurs that dominated the Earth during that period. A study of the bones found showed it had a small head, big barrel chest and was slow-moving and plant-eating, Yates said. It also had the wide, gaping mouth of a browser and foot bones that become thicker towards the inside of the foot - characteristics of a sauropod, which supported its weight on the inside of the foot. But its narrow pointed jaw and shorter forearms was also more in keeping with the smaller, earlier dinosaurs known as prosauropods that date to the Triassic period and were mostly bipedal. While Aardonyx was probably bipedal, the bones in the forearm were shaped like those of a sauropod, suggesting it could also drop onto all fours. "Aardonyx gives us a glimpse into what the steps towards becoming a sauropod involved," Yates said. While dating to the Jurassic period, Aardonyx was probably already by then "a living fossil". The discovery, which was published Wednesday in the Proceedings of the Royal Society, is the latest in a string of finds of sauropods in the Karoo Basin. "We have here in South Africa the cradle of Sauropod-kind," Australian-born Yates said. Bruce Rubidge, director of Wits University"s Bernard Price Institute of Palaeontology, which carried out the research, said he hoped the find would unleash more funding. There were only six scientists from South Africa working on the Karoo rocks, he said. "We need to create more positions," he said.
