An ammonite is a mollusc with a distinctive spiral shell that flourished in the Devonian period (400 million years ago) and died out at the end of the Cretaceous (roughly 66 million BC). In biological terms that was a pretty good run. Homo sapiens will be lucky to survive for even a fraction of this time span.

In Francis Lee’s Ammonite, Kate Winslet plays the mollusc. Or, more precisely, she plays Mary Anning (1799-1847), a legendary fossil-hunter of the early 19th century. In the small Dorset town of Lyme Regis, facing the English Channel, Mary has spent her life scouring the shore and its muddy cliffs, looking for fossils exposed by the action of wind, rain and tides.