How do we know what Earth looked like long before humans appeared? Fossils provide many clues. Palaeontological discoveries help scientists reconstruct past environments, trace the evolution of life and learn about creatures that vanished millions of years ago. From dinosaurs to tiny marine organisms, these remnants of the past preserve snapshots of ancient worlds that no longer exist.

The coiled shells in today's image are the remains of ammonites from the Jurassic Period, when dinosaurs dominated the land and ancient seas teemed with marine life. Though they resembled modern nautiluses, ammonites were more closely related to squid and octopuses. Their chambered shells formed the distinctive spirals that make them some of the world's most recognisable fossils.

Ammonites disappeared alongside the non-avian dinosaurs about 66 million years ago, but they remain invaluable to scientists. Their widespread presence helps researchers date ancient rocks and understand prehistoric seas. Preserved in stone, these shells offer a window into a vanished world.