The Ouranosaurus nigeriensis was a herbivorous iguanodontid dinosaur found only in the Ténéré desert. It could reach a length of seven meters, a height of three and a weight of two tons. Its massive hind limbs were equipped with three toes, which became five in the front legs; among them, the flexible "pinky" was perhaps used for the collection of food, whereas the sharp "thumb" as a weapon or as mate attraction. Usually, it was keeping a quadrupedal gait, but was able to adopt an upright posture if necessary, to reach the highest parts of the vegetation or for self defense. Its mouth had a sort of beak to pull away plants and herbs, and small rear flat teeth to grind them. Along the back and part of the tail were present long neural spines that supported a rigid crest, likely used for thermoregulation (Giancarlo Ligabue Foundation Collection).