In 1965 Philippe Taquet discovered the remains of an ornithopod in rock layers of the Elrhaz Formation, in the Tenere desert of Niger, it consists of a partial skeleton with a fragmentary skull belonging to single individual which was given the catalogue number GDF 1700, the remains sat undescribed until 1988 when paleontologist Souad Chabli coined the name "Gravisaurus tenerensis" in her unpublished dissertation on the animal, however since the name was never published it is invalid, the remains were later briefly described and formally given the name Lurdusaurus arenatus by Taquet and Dale Russellin 1999, a name with similar etymology to "Gravisaurus tenerensis".
Description
Based on the known specimen, Lurdusaurus arenatus had an unusually heavy build compared to other iguanodonts. Their forelimbs were proportionally short and powerfully constructed as were their hands which bore an enlarged thumb claw, their hindlimbs as well were massive and proportionally short, specially the lower leg, the foot was unusually constructed in that the foot bones lacked solid contact with each other suggesting the presence of a fleshy pad that supported most of the weight. Their necks were relatively longer than in their relatives due to their neck vertebra being both more numerous and comparatively elongated. The type specimen would have been about tall at the hips and it was estimated to have approached in length while weighing based on the circumference of its limb bones, lower weight and length estimates have been estimated, however. Due to their unusual body plan, the describers Taquet and Russell suggested that they would have looked superficially like an ankylosaur.
Paleobiology
Lifestyle
Paleontologist Tom Holtz has speculated that, based on its bodily proportions and spreading hands, Lurdusaurus arenatus may have led an aquatic or semiaquatic lifestyle, similar to a hippopotamus.
Habitat
The fossils of Lurdusaurus arenatus were found in the Elrhaz Formation, dating from the late Aptian to the early Albian of the Early Cretaceous period, approximately 112 million years ago. The stratigraphy of the formation and its aquatic fauna suggest that it was an inland fluvial environment, entirely freshwater in nature with a humid tropical climate. The named dinosaur fauna of the regionapart from Lurdusaurus consisted of Ouranosaurus, the sauropod Nigersaurus, the spinosaurid Suchomimus, the carcharodontosaurid Eocarcharia and the abelisaurid Kryptops. The waters moreover were inhabited by the semionotid fish Pliodetes as well as the giant crocodile relative, Sarcosuchus.
