11 - A review of Vectisaurus valdensis, with comments on the family Iguanodontidae

Summary

Abstract

Vectisaurus valdensis is considered to be the imperfectly preserved remains of juvenile Iguanodon. Based on juvenile material of Iguanodon recovered from Nehden (Federal Republic of Germany), Vectisaurus is most probably referrable to I. atherfieldensis.

Ornithopod relationships have been evaluated by reference to the detailed recent systematic reviews of the Ornithischia. Results from this study suggest that the family Iguanodontidae is valid, if more restricted than previously argued; that Tenontosaurus tilletti is more closely related to hypsilophodontians than iguanodontians; and, that Probactrosaurus gobiensis is the sister-taxon of the Hadrosauridae. A revised cladogram of advanced ornithopod dinosaurs is proposed.

Introduction

In 1879, John Wittaker Hulke described the partial, associated skeleton of a small ornithopod that had been recovered from the Wealden Marls near Brixton (Brighstone) Chine (Isle of Wight, southern England). In the description of this material (Figs. 11.1, 11.2, 11.3), which included five dorsal vertebrae, an anterior caudal centrum, and a partial ilium, Hulke recognised several characters that merited the erection of a new genus and species distinct from the then known ornithopods from the Isle of Wight (Hypsilophodon foxii and Iguanodon mantelli). The principal characters by which Hulke distinguished this new taxon were: opisthocoelous dorsal centra with a nearly flat anterior articular surface, a heart-shaped posterior articular surface, a blunt ventral keel on the centra, and the quadrangular appearance of the anterior caudal centrum. Based on the preacetabular process of the ilium, Hulke referred this species to the family Iguanodontidae.