but Paul could not resolve the matter any further until more complete remains are discovered. In 2009, American paleontologist Peter Galton placed Lurdusaurus at the base of Styracosterna and closely allied it with the Chinese Equijubus. He classified more derived iguanodonts into the new clade Iguanodontea. In 2012, Taquet agreed with Paul that it falls outside Iguanodontidae, but was also unsure how exactly Lurdusaurus relates with other iguanodonts. Phylogeny of Iguanodontia according to Galton, 2009 (left) and You and colleagues, 2005 (right) Paleoecology In 2007, paleontologist Thomas R. Holtz Jr. speculated that "Lurdusaurus may have been the dinosaur equivalent to a hippo" as they both share a heavy, stocky body plan. He suggested Lurdusaurus, like the hippo, was a generally slow-moving animal on both land and water, but could reach high speeds when necessary. Generally, iguanodonts are thought to have been predominantly bipedal or facultatively bipedal, and Lurdusaurus, judging by the marked robustness of the limbs, was likely capable of quadrupedal locomotion for an extended period of time. Overall, with its unusual and massive body plan including a small skull, circular chest, powerful and clawed forearms, and flattened femora, Lurdusaurus may have been reminiscent of a ground sloth. In squatting position, it may have resembled an ankylosaur. Taquet and Russell compared the fortified hand with its massive thumb spike to a ball-and-chain flail, and believed it was primarily used for defense. Lurdusaurus was recovered from the Elrhaz Formation, and lived alongside the iguanodonts Ouranosaurus and Elrhazosaurus, the sauropod Nigersaurus, an undescribed titanosaurid, the spinosaurid Suchomimus, the carcharodontosaurid Eocarcharia, the abelisaurid Kryptops, and an undescribed noasaurid. The Gadoufaoua site has also yielded an ornithocheirid pterosaur, and the crocodylomorphs Anatosuchus, Araripesuchus, Stolokrosuchus, and the giant Sarcosuchus. It dates to roughly 112 million years ago during the Early Cretaceous at the Aptian–Albian boundary. Geologically, it is composed of almost entirely cross-bedded fluvial sandstone (the sediments were deposited by rivers), intermittently interrupted by migrating sand dunes. The presence of Nigersaurus suggests widespread forests with soft understory vegetation, such as immature ferns or horsetails. See also Koreaceratops Liaoningosaurus Spinosaurus References Iguanodonts Early Cretaceous dinosaurs of Africa Aptian life Cretaceous Niger Fossils of Niger Fossil taxa described in 1999 Taxa named by Philippe Taquet Taxa named by Dale Russell Ornithischian genera