Charlotte is portrayed as younger than Mary, with Kate Winslet being almost twenty years older than Saoirse Ronan. In reality, Charlotte was a decade older than Mary.
Mr Murchison reports that he is from the geographical society, when in fact he was from the geological society.
The movie begins with a maid on her hands and knees proceeding forwards as she scrubs a floor - but this means that in doing so, she crawls over her own handiwork. For a clean floor, it was very important to scrub while proceeding backwards.
Elisabeth Philpot was a [far older] palaeontological mentor to Mary Anning since childhood. NOT remotely her former jilted lover. Peer scientists striving to make scientific discoveries.
There is not a shred of evidence that Mary Anning was gay, but much to prove she was involved with a male scientist.
When Mary and Charlotte are lifting the large ammonite they discover onto the strap of wood on the beach there is a moment when the weight of the stone is revealed to be obviously much lighter than they are portraying.
The ichthyosaur and ammonite fossils shown at the beginning are too light and too easily moved to be real fossils, and are clearly reproductions made of a much lighter material.
The front door of the Murchison house when Mary visits has a very 21st century security spy hole.
The maid who comes in to dress Charlotte for her first day out with Mary addresses her as "Miss." Despite her youth, as a married woman Charlotte would properly be addressed as "Ma'am" by servants.