Gideon Algernon Mantell MRCS FRS (3 February 1790 – 10 November 1852) was an English obstetrician, geologist and palaeontologist.

He explored pits and quarries in the surrounding areas, discovering ammonites, shells of sea urchins, fish bones, coral, and worn-out remains of dead animals.

As a result, Gideon was educated at a dame school in St. Mary's Lane, and learned basic reading and writing from an old woman.

[5] He served as an apprentice to Moore in Lewes for a period of five years, in which he took care of Mantell's dining, lodging and medical issues.

[9] Four days later, he received a certificate from the Lying-in Charity for Married Women at Their Own Habitations that allowed him to act in midwifery duties.

In the wake of the cholera, typhoid and smallpox epidemics, Mantell found himself quite busy attending to more than 50 patients a day and delivering between 200 and 300 babies a year.

[12] Although mainly occupied with running his busy country medical practice, he spent his little free time pursuing his passion, geology, often working into the early hours of the morning, identifying fossil specimens he found at the marl pits in Hamsey.

Since she was not 21 and still technically a minor under English law, she had to obtain permission from her mother and a special licence to marry Mantell.

Then, in 1822, shortly before finishing his first book (The Fossils of South Downs), his wife found several large teeth (although some historians contend that they were in fact discovered by himself), the origin of which he could not ascertain.

It was an immediate success with two hundred subscribers including King George IV at Carlton House Palace, who wrote a letter stating, "His majesty is pleased to command that his name should be placed at the head of the subscription list for four copies.

Galvanised and encouraged, Mantell showed the teeth to other scientists but they were dismissed as belonging to a fish or mammal and from a more recent rock layer than the other Tilgate Forest fossils.

Although according to Charles Lyell, Cuvier made this statement after a late party and apparently had some doubts when reconsidering the matter when he awoke, fresh in the morning.

Mantell was still convinced that the teeth had come from the Mesozoic strata and finally recognised that they resembled those of the iguana, but were twenty times larger.

Years later, Mantell had acquired enough fossil evidence to show that the dinosaur's forelimbs were much shorter than its hind legs, therefore proving they were not built like a mammal as claimed by Sir Richard Owen.

Financially destitute, Mantell offered to sell the entire collection to the British Museum in 1838 for £5,000, accepting the counter-offer of £4,000.

[17] Despite being bent, crippled and in constant pain, he continued to work with fossilised reptiles and published a number of scientific books and papers until his death in November the 10th 1852.

He is buried at West Norwood Cemetery within a sarcophagus attributed to Amon Henry Wilds[18] that replicates the sanctuary of Natakamani's Temple of Amun.

Sixty-seven books and memoirs appear in Agassiz and Strickland's Bibliographia Zoologiæ, and forty-eight scientific papers in the Royal Society's Catalogue.