 Unlike other purported herding dinosaurs ( especially hadrosaurs and ceratopsids ) , there is no evidence that Iguanodon was sexually dimorphic , with one sex appreciably different from the other . At one time , it was suggested that the Bernissart I. " mantelli " , or I. atherfieldensis ( Dollodon and Mantellisaurus , respectively ) represented a sex , possibly female , of the larger and more robust , possibly male , I. bernissartensis . However , this is not supported today . 
