But this film from director Francis Lee (“God’s Own Country”) nudges Anning’s legacy to the side, focusing on her halting romance with a depressed young wife (Saoirse Ronan) who’s been pawned off on Anning, for an unofficial apprenticeship, by a bored husband (James McArdle). Being a lesbian period piece, the film’s earned inevitable comparisons to last year’s “Portrait of a Lady on Fire.” Sure, it’s similar, minus the chemistry, humor and joy. There are definitely corsets in both.

Winslet is riveting as always, though, as a work-obsessed misanthrope who finds calcified feces more interesting than the tourists who visit her shop in the British town of Lyme Regis. Lee’s naturalist style makes Anning’s forays to the beach intensely visceral; you feel the chill of the gray clay she claws through in search of cliffside treasures.

Ronan dials down her vivaciousness to play Charlotte Murchison, suffering from “melancholia” that, the film suggests, stems from losing a baby. (Murchison was also a real person, who became a geologist, and was indeed friends with Anning.) Both women curl into themselves, like Anning’s spiral ammonite mollusk fossils. If that metaphor sounds glaring, it is. A tenuous friendship grows between the two, but their graphic erotic collisions are so sudden — and so dissonant — that they feel more startling than satisfying.

The great Fiona Shaw appears as a neighbor with whom, it’s suggested, Anning might have had a short-lived relationship, and Gemma Jones is haunting as Anning’s aged mother, whose odd behavior makes more sense when you learn she lost eight of her 10 children.

All the pieces are here for “Ammonite” to work as an introspective look at women’s lives, and love, in a male-centric era. But Lee’s grim tone is relentless, and I’m curious why: He’s invented a queer relationship where there’s no historical evidence for one. Why not let it take flight, then, rather than leaving it stuck in the mud?