50 Pence - Elizabeth II Hylaeosaurus, Silver Proof

Part of the Royal Mint's three-coin Dinosaur series, the Hylaeosaurus holds a specific distinction within paleontological history: it was one of the three genera — alongside Megalosaurus and Iguanodon — that Richard Owen used in 1842 to define the entirely new taxonomic grouping Dinosauria. Owen announced the concept at the British Association for the Advancement of Science meeting in Plymouth, drawing on specimens already held by the Natural History Museum. The animal itself was first described by Gideon Mantell in 1833 from fragmentary Sussex Wealden remains, most of which are still embedded in the original matrix block and have never been fully extracted.