Fukuisaurus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of herbivorous dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

 from the Early Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

. It was an ornithopod

Ornithopod

Ornithopods or members of the clade Ornithopoda are a group of ornithischian dinosaurs that started out as small, bipedal running grazers, and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, and dominated the North American...

 which lived in what is now Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

.

Remains of Fukuisaurus (フクイサウルス) were discovered in 1989, in the Kitadani quarry in Katsuyama, Fukui

Katsuyama, Fukui

is a city located in Fukui, Japan.As of October 1, 2005, the city has an estimated population of 26,961 and the density of 106.28 persons per km²...

 Prefecture, in rocks from the Kitadani Formation

Kitadani Formation

The Kitadani Formation is a geological formation in Fukui, Japan whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Vertebrate paleofauna:...

, dating to the Barremian

Barremian

The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...

. The type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

, Fukuisaurus tetoriensis, was described in 2003

2003 in paleontology

-New taxa:-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-New taxa:-Non-mammalian:-newly named:-Conifers:-Angiosperms:...

 by Yoshitsugu Kobayashi and Yoichi Azuma. The genus name refers to Fukui; the specific name to the geological Tetori Group. The type specimens or cotypes are FPDM-V-40-1, a right maxilla, and FPDM-V-40-2, a right jugal. Further elements of a skull and a right sternal plate had been recovered. Since 2003 much more extensive finds have been made and much of the skeleton is now known.

Fukuisaurus is a relatively small species. In 2010 Gregory S. Paul

Gregory S. Paul

Gregory Scott Paul is a freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dinosaurs and his detailed illustrations, both live and skeletal...

 estimated the length at 4.5 metres, the weight at four hundred kilograms. Being a bipedal, optionally quadrupedal, animal, it was similar in general build to Iguanodon

Iguanodon

Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs...

, Ouranosaurus

Ouranosaurus

Ouranosaurus is an unusual genus of herbivorous iguanodont dinosaur that lived during the early Cretaceous about 110 million years ago in what is now Africa. Ouranosaurus measured about seven to eight meters long...

and Altirhinus

Altirhinus

Altirhinus is a genus of iguanodontian ornithopod dinosaur from the Early Cretaceous Period of Mongolia.-Description:Altirhinus was herbivorous and bipedal when walking or running, but probably became quadrupedal when feeding from the ground. According to the original description, the entire body...

. According to the describers Fukuisaurus was exceptional in that its skull was not kinetic: the tooth-bearing maxilla

Maxilla

The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...

 would be so strongly fused to the vomer

Vomer

The vomer is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones.-Biology:...

 that a sideways chewing motion would have been impossible.

A cladistic analysis showed that Fukuisaurus was a basal member of the Hadrosauroidea

Hadrosauroidea

Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and their close relatives. Many primitive hadrosauroids, such as the sail-backed Ouranosaurus, have traditionally been included in a paraphyletic "Iguanodontidae"...

, less derived than Altirhinus.

External links

• Fukuisaurus from DinoData.org (Contains abstract of original paper describing the genus)
• Iguanodontia