Waxaa la sheegaa in xaaska Gideon Mantell, Mary Ann, ay soo ogaatay ilkaha ugu horeeya ee Iguanodon ee jilicsan ee Tilgate Forest ee Whitemans Green, Cuckfield, Sussex, England, 1822 halka ninkeedu uu booqanayay bukaan. Si kastaba ha ahaatee, ma jirto wax caddeyn ah in Mantell uu xaaskiisa la socday isaga oo daaweynaya bukaanka. Intaa waxaa dheer, wuxuu qirtay in 1851 in uu isaguba helay ilkaha, inkasta oo uu horey u sheegay in 1827 in Mrs. Mantell ay dhab ahaantii ka heshay ilkaha ugu horeeya ee loo yaqaan Iguanodon.
Xayawaanka loo yaqaan 'Iguanodon'