Patagonia has not always been the cold, arid and dry place it is today. About 17Ma – because the Andes were much lower allowing humid winds from the west to reach the area – it consisted of substantial forests and grasslands. It was also inhabited by strange and wonderful animals, many of which are now extinct.

Most PalAss guides, making up its wonderful library of guides to fossils, are about UK fossils. This is the only one that concentrates solely on non-UK geological formations. It is about two formations found in northeast Brazil and so is a complete departure from the usual format.