The term "dinosaur" originated in 1842 when British anatomist Richard Owen (later Superintendent of the British Museum's Natural History Department) collectively named three giant reptiles discovered up to that time (Megalosaurus, Iguanodon, and Hylaeosaurus) as "terrible (wonderful) lizards (Dinosauria)".
As the second coin commemorating the discovery of dinosaurs, this coin featuring Iguanodon was issued.

Iguanodon was discovered by Gideon Mantell, a country doctor, and first scientifically described in 1825. The coin is engraved with "MANTELL 1825" at the bottom to indicate this.