A taxonomy of iguanodontians (Dinosauria: Ornithopoda) from the lower Wealden Group (Cretaceous: Valanginian) of southern England

This short review discusses current understanding of the history, anatomy and taxonomy of the lower Wealden Groupaged (Valanginian ~141–137Ma) iguanodontian dinosaurs from southern England. English Wealden iguanodontian taxonomy has been the subject of comment and scrutiny since the latter half of the 19 th century. As proposed over two decades ago, iguanodontians recovered from quarries across this geographic region can be subdivided into anatomically and chronologically distinct assemblages. A review of the lower Wealden Group (Valanginian) assemblage (formerly understood to comprise the relatively poorly known and understood taxa Iguanodon dawsoni, Iguanodon fittoni and Iguanodon hollingtoniensis) establishes the presence of two diagnosable taxa: Barilium dawsoni (Lydekker, 1888) comb. nov. and Hypselospinus fittoni (Lydekker, 1889) comb. nov. The upper Wealden Group (Hauterivian–Lower Aptian) assemblage comprises Iguanodon bernissartensis and Mantellisaurus atherfieldensis. Recent suggestions concerning the creation of additional new Wealden Group taxa reflect systemic misunderstandings of the actual skeletal material. A detailed taxonomic review of all Wealden Group iguanodontians is in preparation.