Is this the only existing photograph of renowned palaeontologist and geologist Mary Anning? Suzanne Pilaar Birch celebrates thewoman who helped make geology a science, 215 today and subject of a Google doodle.

Mary Anning, born in 1799, was the discoverer of the famous ichthyosaur and plesiosaur fossils on the Jurassic coast of Dorset. Following her death in 1847, Charles Dickens wrote of her contribution to geology: 'It was not a science when she began to discover, and so [she] helped to make it one.' The Natural History Museum in London has called her the 'greatest fossil hunter ever known'.

Simply titled The Geologists, the image above is known as a calotype or salt print. It is one of the earliest examples of photography, captured by the pioneer who developed the method, William Henry Fox Talbot, on the Dorset coast in 1843. Could it show Anning? The dress of the woman looks strikingly similar to that in Anning's portrait.

We know that Henry de la Beche, president of the British Geological Survey and a close friend of Anning, had corresponded with Talbot in February of that year, requesting him to take geological photographs. Talbot was initially reticent, but in March 1843 agreed to meet with de la Beche. We know from letters and other sources they became friends. Could the woman be Anning and the man de la Beche?

The date, location, clothing, and correspondence make tantalising evidence.