Triunfosaurus (meaning "Triunfo Basin reptile") is a genus of somphospondylan sauropod dinosaur from the Early Cretaceous of Brazil. It contains a single species, T. leonardii, described by Carvalho et al. in 2017. As a genus, Triunfosaurus can be distinguished from all other titanosaurs by the unique proportions of its ischium. It was initially described as a basal titanosaur, making it the earliest basal titanosaur known; however, subsequent research questioned the identification of the taxon as a titanosaur, instead reassigning it to the Somphospondyli. Description Triunfosaurus can be distinguished from other titanosaurs by two autapomorphies, or unique traits that distinguish it from other titanosaurs. Namely, the part of the ischium touching the pubis is half the height of the entire ischium, and the shaft of the ischium makes an angle of less than 70° with the acetabular portion, which contributes to the hip socket. It also presents a unique combination of vertebral characters not seen otherwise among titanosaurs, which are described below. The vertebrae from near the front of the tail have short and robust processes, or prezygapophyses, on their front edges; these processes are also slightly angled upwards from the horizontal. At the top of the vertebrae, the neural spines are small and bear processes along their midlines that are expanded near the top. On the side of the vertebrae, the transverse processes are placed near the back of the bones, and are also slightly angled upward. The back half of the sides of the centra are strongly concave, while the depressions on the sides of the vertebrae known as pleurocoels are rather small. The internal textures of the centra are not sponge-like, or camellate. In the haemal arches from the bottoms of vertebrae near the front of the tail, the holes that they form with the centra - the haemal canals - are narrow, and the arches themselves are relatively straight. The bottom ends of the arches are rounded and expanded, and the arches connect to the centra with simple facet joints at the tops of the bones. Near the middle of the tail, the haemal canals are smaller in height but proportionally wider, and the haemal arches overall become very flattened, including the bottom ends. The arches also are slightly concave, and the joints with the centra are situated closer to the back end. At the base of the arch on the back side, two small crests form