British botanist and historian of science (1885-1962).
Hugh Hamshaw "Ham" Thomas FRS (29 May 1885 – 30 June 1962), was a British paleobotanist. One of his major contributions was to combine thinking about plant fossil anatomy with ecology, and consideration of how these related to non-extinct plants. He also led a change in attitude to fossils, from museum-based to a more exploratory, field-work based subject.