Describer

Kobayashi & Azuma, 2003

Time

Cretaceous Early

Classification

Ornithischia Ornithopoda Iguanodontia Iguanodontidae

Diet

Herbivore

Fossilsite

Kitadani Formation, Tetori Group of Fukui Prefecture, Japan

Info

Genus - Typespecies - Skull

Kobayashi and Azuma, 2003. A new iguanodontian (Dinosauria; Ornithopoda), form the lower Cretaceous Kitadani Formation of Fukui Prefecture, Japan. Journal of Vertebrate Paleontology: Vol. 23, No. 1, pp. 166-175.

Abstract

The skull material of the new iguanodontian dinosaur, Fukuisaurus tetoriensis gen. et sp. nov., was discovered from the fluvial deposits of the Lower Cretaceous Kitadani Formation, Tetori Group, Fukui Prefecture, Japan.

Some features of Fukuisaurus show affinities with Iguanodon, Ouranosaurus and Altirhinus, referred to as Iguanodontidae by some. A phylogenetic analysis using mainly cranial characters shows that Fukuisaurus is a definitive derived non-hadrosaurid iguanodontian and implies that Fukuisaurus is more derived than the clade of Iguanodon + Ouranosaurus and more basal to the clade of Altirhinus, Probactosaurus, Eolambia, Protohadros, Bactrosaurus, Telmatosaurus, and hadrosaurids .

It also supports that Iguanodontidae is paraphyletic by the exclusion of Altirhinus as suggested previously. The presence of Fukuisaurus indicates a wider geographical distribution of the group in eastern Asia. The occurrences of derived non-hadrosaurid iguanodontians from the Kitadani Formation and other formations in Japan support a dispersal of this group into eastern Asia by the Early Cretaceous and its temporal range extension in Japan.

Fukuisaurus possesses a strong maxilla-vomer articulation, indicative of the independent acquisition of a non-pleurokinetic skull (not present in Hypsilophodon, Iguanodon, and hadrosaurids).

Carpenter & Ishida (2010) Early and “Middle” Cretaceous Iguanodonts in Time and Space Journal of Iberian Geology 36 (2) 145-164

Fukuisaurus tetoriensis Kobayashi and Azuma 1993

Locality

near Katsuyama City, Fukui Prefecture, Japan.

Horizon

Okurodani Formation (formerly Kitadani Formation - Matsukawa et al.,2003)

Age

Hauterivian (Fuijita, 2003).

Comments

This taxon is represented by considerably more material than when first described. The ilium also has not been described previously. Superficially, it resembles the ilium of Equijubus and “Iguanodon mantelli”, but differs in a long, overhanging (laterally projecting) lateral iliac crest, and small, triangular expansion onto the postacetabular process.