Born in the coastal southern English village of Lyme Regis in Dorset, Mary Anning was (it is said) marked out for an unusual life at the age of 15 months. In 1800 a lightning strike in the village caught four women in the open, killing three; the survivor was young Mary.
Mary's father Richard was a cabinetmaker who supplemented his income by mining the coastal cliff-side fossil beds near Lyme Regis, then selling his finds to tourists. When he died of tuberculosis in 1810, the Anning family was left without support, and Mary (along with her brother Joseph) began collecting full-time in an effort to gain some income.
Fossil collecting was in vogue in the late 18th Century and early 19th Century, at first as a pastime akin to stamp collecting but gradually transforming into a science as the importance of fossils to geology and biology became understood. Anning catered to the commercial aspects of the field, selling her finds, but soon plugged into the scientific community as a major source of that income.
The first cause of this connection was one of Anning's discoveries a few months after her father's death, the skeleton of an ichthyosaur. Her brother had discovered the skull of what appeared to be a large crocodile a year earlier. The rest of the skeleton was not to be found at first, but Mary came up with it after a storm scoured away a portion of the cliff containing it. This was the first complete skeleton of an ichthyosaur ever discovered, though not the first ichthyosaur fossil ever, as is sometimes reported (the genus had been described in 1699 from fragments discovered in Wales). Nevertheless, it was an important find, and was soon described in the Transactions of the Royal Society. Anning was no more than twelve years old at the time of her discovery.
As her reputation grew, Anning came to the attention of Thomas Birch, a wealthy fossil collector. Disturbed by the poverty of Mary and her family he arranged for the sale of his own fossil collection, the proceeds of which (some £400) were given to the Annings. Put on a sure (if somewhat spartan) financial footing for the first time in a decade, Mary carried on with her fossil collecting even after her brother gained employment as an upholsterer.
Her next major discovery was a real first, the first-ever skeleton of a plesiosaur in 1821. The fossil she found was of a Plesiosaurus dolichodeirus and is still considered the type fossil of the species. In 1828 she discovered an important fossil of a pterodactyl, a Pterodactylus macronyx, the first found outside of Germany.
Those were the three finds that made her mark on history, but she continued collecting for the remainder of her life, making numerous other contributions to early paleontology. In her late thirties she was granted an annuity by the British Association for the Advancement of Science in return for her efforts. Anning died at the age of 47, of breast cancer; a few months beforehand she had been made an honorary member of the Geological Society of London despite being ineligible for regular membership due to the sexist mores of the time.
Taken all together, Mary Anning's discoveries were one of the key pieces of evidence for extinction. Until her time it was widely believed that animals did not become extinct; any oddities found were explained away as still living somewhere in an unexplored region of the earth. The bizarre nature of the fossil skeletons found by Anning struck a heavy blow against this argument, and set the stage for real understanding of life in earlier geologic ages. For a time after her death Mary dropped into obscurity, but in recent decades she has been rediscovered and lauded as one of the most important and picturesque figures in early paleontology.
Links "Duria antiquior", an illustration of ancient Dorset designed to highlight Mary Anning's discoveries