Charles Helm and Andrew Carr

The urge to draw images in sand, or create sand sculptures, seems to be irresistible, as a walk on many a modern beach or dune surface will show. Sand is a vast canvas – and may have been used as one for far longer than people realise.

When people think of ancient palaeoart, cave paintings (pictographs), rock engravings (petroglyphs), images on trees (dendroglyphs) or arrangements of rocks in patterns (geoglyphs) might come to mind. Until recently it was only possible to speculate that the oldest art might have been in sand.

We are, respectively, a vertebrate ichnologist who studies the fossil tracks and traces of vertebrates, and a physical geographer, interested in the functioning and long-term evolution of coastal landscapes.

We’re part of a team that has spent the past 15 years studying vertebrate tracksites on South Africa’s Cape south coast that date back to