[D] Owenodon hoggi [sG] [T]
Cretaceous Early Valanginian Hauterivian Barremian
Ornithischia Ornithopoda [Styracosterna]
Upper Purbeck Beds, Dorset, England
Owenodon hoggi (Galton 2009) > Iguanodon hoggi (Owen, 1874) >> Camptosaurus hoggi (Norman & Barrett, 2002)
Iguanodon hoggii Owen, 1874 is based on an almost complete right dentary (NHM R2998), with most of the teeth preserved in situ, from the Purbeck Limestone Formation (=Durlston Formation, Upper Purbeck, mid-Berriasian, Allen & Wimbledon, 1991) of Durlston Bay, Swanage, Dorset. The dentary was originally partly exposed in medial view, on a block of limestone, but much of the bone surface was damaged by mechanical preparation. It was prepared free of matrix using acetic acid in 1975 to reveal the almost complete but transversely crushed dentary with 14 preserved alveoli, most with teeth, plus a rudimentary alveolus 15 medial to the coronoid process, so the adult tooth count was at least 15.
Given that NHM R2998 is definitely not referable to the Iguanodontoidea sensu Norman (2002, 2004), the differences from the dentary of Camptosaurus dispar, and the definable nature of the teeth, Iguanodon hoggii Owen, 1874 is made the type species of the new genus Owenodon. Compared to the dentary of Camptosaurus, that of the holotype (NHM R2998) of Owenodon hoggii (Owen, 1874) is deeper with the dental margin and tooth row arched and a longer symphysis ; the lingual surface of crowns equally subdivided by a simple, well-defined, primary ridge and a parallel and equal-sized secondary ridge, tertiary ridges essentially absent, no abbreviated cingulum formed by inrolling of the denticulate distal edge of the lower distal corner of the crown. Given the more derived form of the teeth, Owenodon could be tentatively referred to the next clade, the Styracosterna Sereno 1986 sensu Norman (2004, p. 434 ; for Lurdusaurus, Equijubus). (Galton 2009)
>> Iguanodon hoggi (Owen, 1874)