Muttaburrasaurus was a genus of herbivorous iguanodontian ornithopod dinosaur, which lived in what is now northeastern Australia sometime between 112 and 103 million years ago during the early Cretaceous period. It has been recovered in some analyses as a member of the iguanodontian clade Rhabdodontomorpha. After Kunbarrasaurus, it is Australia's most completely known dinosaur from skeletal remains. It was named after Muttaburra, the site in Queensland, Australia, where it was found. Description Muttaburrasaurus was about and weighed around . The femur of the holotype has a length of . Whether Muttaburrasaurus is capable of quadrupedal movement has been debated; it was originally thought to be an "iguanodontid"; thought recent studies indicate a rhabdodont position. Ornithopods this basal were incapable of quadrupedal movement. Originally reconstructing Muttaburrasaurus with a thumb spike, Molnar later doubted such a structure was present. The foot was long and broad, with four toes. The skull of Muttaburrasaurus was rather flat, with a triangular cross-section when seen from above; the back of the head is broad but the snout pointed. The snout includes a strongly enlarged, hollow, upward-bulging nasal muzzle that might have been used to produce distinctive calls or for display purposes. However, as no fossilised nasal tissue has been found, this remains conjectural. This so-called bulla nasalis was shorter in the older Muttaburrasaurus sp., as is shown by the Dunluce Skull. The top section of the bulla of the holotype has not been preserved, but at least the second skull has a rounded profile. Discovery and species The species was initially described from a partial skeleton found by grazier Doug Langdon in 1963 at Rosebery Downs Station beside Thomson River near Muttaburra, in the Australian state of Queensland, which also provides the creature's generic name. The remains were collected by paleontologist Dr Alan Bartholomai and entomologist Edward Dahms. After a lengthy preparation of the fossils, it was named in 1981 by Bartholomai and Ralph Molnar, who honoured its discoverer with its specific name langdoni. The holotype, specimen QM F6140, was found in the Mackunda Formation dating to the Albian-Cenomanian. It consists of a partial skeleton with skull and lower jaws. The underside of the skull and the back of the mandibula, numerous vertebrae, parts of the pelvis, and parts of the front and hind limbs have been preserved. Some teeth have been discovered further north, near Hughenden, and south at Lightning Ridge, in northwestern New South