Dinosaur bones were first noticed weathering out of the exposed rocks of Spion Kop (a game farm in the Senekal district of the Free State) in the early 1990's. However it was not until 2004 that excavations began there in earnest. Several fossil bearing sites have been recognized on the farm but it is a small site known informally as 'Marc's Quarry' that has produced an outstanding collection of close to four hundred well-preserved bones. Most of these bones belong to a new genus and species of large herbivorous dinosaur that has been named Aardonyx celestae. The genus name means 'Earth Claw' in a combination of Afrikaans and Greek. The species name honours Celeste Yates who spent two years cleaning away the hard ironstone matrix which encased the bones. Aardonyx lived during the Early Jurassic Period (about 185-190 million years ago). It is an unusually large dinosaur for its time with the larger of the two skeletons found at Marc's Quarry probably reaching 8 metres in length. Nonetheless work on the microstructure of its bones indicates that it was a juvenile that had not stopped growing. Aardonyx shares some characters of its anatomy with sauropod dinosaurs which were the largest of all dinosaurs. Dr Yates will discuss this important find.

Adam was born in 1972 in Adelaide, S. Australia. He developed a passion for fossils and dinosaurs early in his life. Much of his childhood was spent collecting fossils along the banks of the River Murray in S. Australia. He attended the University of Adelaide, majoring in Geology and graduating with first class honours in 1994. He then moved to Melbourne to study for his PhD at La Trobe University. His PhD topic was based on Triassic amphibian fossils from Australia. After he received his PhD in 1999 he realised a lifelong dream to work with dinosaurs and moved to Bristol, England to study the early evolution of plant-eating and gigantism in dinosaurs with Prof Michael Benton. This postdoc sent him to all corners of the world, looking at early dinosaur fossils. One of his trips brought him to South Africa, where he recognised that a skeleton held at Wits belonged to the earliest known sauropod dinosaur. After Bristol, Adam continued his connection with South Africa by moving to Johannesburg to take up a position at the Bernard Price Institute for Palaeontological Research at Wits. He is currently running a series of expeditions to the Free State, funded by National Geographic which has led to the discovery of several new species of dinosaur, including Aardonyx.