Sergio Hanquet / Green sea turtle (Chelonia mydas), two viewed from above. Tenerife, Canary Islands.

Philippe Clement / Lined top shells (Phorcus lineatus) in a rock pool, Normandy, France, June

Philippe Clement / Lined top shells (Phorcus lineatus) and Common european limpets (Patella vulgata) in a rock pool, Normandy, France, June.

David Fleetham / Tiny eyes of Spider conch / Scorpion shell (Lambis scorpius) peering from underside of shell, Philippines.

Brian Bevan / Two Giant african snails (Achatina fulica) emerging from their shells and looking around, UK. Captive.

Ingo Arndt / Caddisfly (Limnephilus sp.) case built of sticks, wood fragments, seeds, snail shells and plant stems, Germany, November.

Ingo Arndt / Land snails (Polymita picta) shells, Cuba. Endemic species.

Ingo Arndt / Land snail (Polymita picta) collection of shells showing variation in patterning, Cuba. Endemic species.

Laurent Geslin / Woman from the Turmi village with traditional hair braiding with mud and butter, and shell jewellery, Omo valley, Ethiopia, 2006

Philippe Clement / Fossils of belemnites and ammonites on shingle beach near Lyme Regis along the Jurassic Coast, Dorset, UK, November 2012

Philippe Clement / Ammonite fossils (Promicroceras planicosta) on shingle beach near Lyme Regis along the Jurassic Coast, Dorset, southern England, UK, November 2012

Sandra Bartocha / Sea shells in sand, North sea, Germany, September