Kate Winslet and Saoirse Ronan are to star in a film exploring a fictional romance between Mary Anning, the fossil pioneer, and another woman.

The film, Ammonite, will be set in a British coastal town in the 1840s and is understood to follow Anning as she becomes the nursemaid for a wealthy woman from London who visits for a period of convalescence.

Producers have not announced which characters will be played by Winslet and Ronan, but the film will be written and directed by Francis Lee.

Lee is best known for his 2017 film God’s Own Country, about the gay relationship between a farmer in Yorkshire and a migrant worker from Romania.

Anning is renowned for her discoveries of Jurassic fossils around Lyme Regis, Dorset, and in 2010 she was named as one of the Royal Society’s ten most influential British women in science.