Aardonyx ( Earth Claw )

Aardonyx (Afrikaans Aard “earth” + Greek onux, “nail, claw”) is a genus of basal sauropodomorph dinosaurs found in the Early Jurassic Elliot Formation of South Africa. It is characterized by arm features that are in between prosauropods and sauropods, and usually moved bipedally, but could change to quadrupedal movements like Iguanodon.

Australian paleontologist Adam Yates and his team's discovery of the genus was announced in the online version before publication within Proceedings of the Royal Society B in November 2009 and is scheduled to be published in the March issue of. British paleontologist Paul Barrett of the Natural History Museum, London, said that finding Aardonyx helps to fill a marked gap in our knowledge of sauropod evolution, showing how a primarily two-legged animal could start to acquire the specific features necessary for a life spent on all-fours.

Matthew Bonnan, a co-author of the study, states that walking quadrupedally and bearing weight on the inside of the foot is a trend that started very early in these dinosaurs, much earlier than previously hypothesized.