At Argentina’s Sanagasta Geological Park, there is a volcanic nursery for giants. It’s a site that is strewn with the fossilised eggs of giant dinosaurs – sauropods. Each of their 80 or so egg clusters sits next to a geyser, a hot vent or other volcanically heated sites. This is no coincidence – eggs need moisture and heat to incubate properly and big eggs are particularly demanding. These dinosaurs were using the planet to keep their babies warm.

Argentina is a haven for any palaeontologist looking for dinosaur eggs. Different provinces have yielded several large nesting sites. Most belonged to the giant sauropods and some even contain eggs with fossilised embryos inside. The sites have told us much