Late nineteenth century studies of Aboriginal rock art failed to recognize that a variety of styles existed. | The extreme age of the earliest Aboriginal rock art has been established but the interpretation of rock art images is still debated. | A sequence from geometric to more representative art fits many sites but does not necessarily indicate a progression from simple to complex meaning. | In determining the way in which Australian rock art was organized, archaeologists have made little distinction between geometric and figurative elements. | Older examples of rock art consist of simple, repeated geometric patterns while later rock art includes figures and animals. | Aboriginal informants were able to explain the meanings of ancient rock art symbols. |