Most of the interior of the northern half of the island is taken up by a large granite batholith that was created by substantial volcanic activity around 60 million years ago in the Paleogene period .
Most of the interior of the northern half of the island is taken up by a large granite batholith that was created by substantial volcanic activity around 60 million years ago in the Tertiary period .
Mantell 's work on the structure and life of `` Iguanodon '' began the scientific study of dinosaurs . In 1822 he was responsible for the discovery ( and the eventual identification ) of the first fossil teeth , and later much of the skeleton , of `` Iguanodon '' .