Illustration of 'Strata of Tilgate Forest in Surrey' showing Gideon Mantell (seated) while two workmen excavate a partly exposed fossil spine of Iguanodon. The strata are labelled as: 1 Loam, 2 Sand and soft Sandstone, 3 Calciferous sandstone (fossil bearing), 4 Blue Clay or Marl. Drawn by F. Pollard, lithographed by P. Gauci, printed by Graf & Soret. From 'The Geology of the South East of England' by Gideon Mantell, 1833, published by Longman, Rees, Orme and Brown of Paternoster Row. Gideon Mantell made some of the world's first dinosaur discoveries here, including Iguanodon (1822) and Hylaeosaurus (1833). Quarry men would often keep specimens they found in the course of their work for his later inspection. Many of Mantell's Tilgate specimens were vital in Richard Owen's recognition and naming of the group Dinosauria.