Describer

Norman 2010

Time

Cretaceous Early Valanginian

Classification

Ornithischia Ornithopoda Iguanodontia

Diet

Herbivore

Fossilsite

Hastings Beds, St Leonards-on-Sea, East Sussex, England

Info

Barilium dawsoni (Norman 2010) > Iguanodon dawsoni (Lydekker, 1888) >> Torilion dawsoni (Carpenter 2010) (Ishida 2010)

Barilium dawsoni (Norman 2010) > Sellacoxa pauli (Carpenter & Ishida 2010)

Lectotype

NHMUK R 798 and R802, a dorsal vertebra and a left ilium

Abstract

This short review discusses current understanding of the history, anatomy and taxonomy of the lower Wealden Group-aged (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 19th 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. Barilium is a genus of iguanodontian dinosaur which was first described as a species of Iguanodon (Iguanodon dawsoni) by Richard Lydekker in 1888, the specific name honouring the discoverer Charles Dawson.

In 2010 it was reclassified as a separate genus by David Norman. The generic name Barilium is derived from Greek barys, \\\"heavy\\\", and Latin ilium.Later in 2010, Kenneth Carpenter and Yusuke Ishida independently assigned it to the new genus Torilion, which is thus a junior subjective synonym of Barilium. It is known from two partial skeletons found near St Leonards-on-Sea in East Sussex, England,from the middle Valanginian-age Lower Cretaceous Wadhurst Clay. Lydekker based the species on the syntype series BMNH R798, 798a, 803-805, 806, 798b, 802, 802a and 799-801. Norman chose NHMUK R 798 and R802, a dorsal vertebra and a left ilium, as the lectotype. A contemporary of Hypselospinus (also once thought to be a species of Iguanodon),

Barilium was a robust iguanodontian estimated at 8 metres long (26.2 ft). Barilium is separated from Hypselospinus on the basis of vertebral and pelvic characters, size, and build.For example, Barilium was more robust than Hypselospinus, with large Camptosaurus-like vertebrae featuring short neural spines, whereas Hypselospinus is known for its \\\"long, narrow, and steeply inclined neural spines\\\"