Kate Winslet and Saoirse Ronan to star in film portraying fictional romance between Mary Anning and another woman

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.

However her work, including the unearthing in around 1811 of a 17-foot ichthyosaur skeleton when she was just 12, went largely uncredited in her lifetime because she was a woman.

Anning’s other finds included the skeleton of a pterodactyl, a winged dinosaur, in 1828.

She was from a poor family and never married or had children, and some aspects of her personal life, including any romantic relationships, remain largely unknown.

Tracy Chevalier, a novelist who wrote a fictional book based on Anning's life, has speculated she may have been romantically attached to an army officer.

She told the BBC in 2010: “There's evidence to suggest Mary had a romantic relationship that ended badly, but no one knows with whom.

"Lieutenant-Colonel Thomas James Birch organised an auction of specimens he had purchased from the Anning family in 1820 which raised £400.

"That was an awful lot of money in those days and he donated it back to the Anning family.

"I think that was a huge romantic gesture."

Ammonite has been developed by See-Saw Films, the British Film Institute and BBC Films, according to Deadline, the entertainment website which revealed the castings.

Production is expected to start in March.