Campananeyen

Campananeyen had a very thin and fragile ilium (hip bone), so thin that scientists gave it the species name fragilissimus, meaning 'the most fragile'.1

Its bones were extremely pneumatized, meaning they were filled with air pockets, which made the skeleton lighter. The name Campananeyen comes from the Mapuche word for 'air'.1

The quadrate fossa, a large pit on the back of the skull's cheek bone, was 30 to 70 percent larger in Campananeyen than in any other known rebbachisaurid.1

Unlike most rebbachisaurids, Campananeyen had hyposphene-hypantrum joints between its vertebrae, which helped lock the backbone together. Its hyposphene was hollow and ovoid, like in Nigersaurus.1

The sacral ribs of Campananeyen had a unique 'dorsal alar arm' that helped support the leg muscles, especially the muscle that pulls the thigh forward.1

Campananeyen lived in the Kokorkom Desert, a huge sandy desert with some oases, alongside other dinosaurs like the giant predator Giganotosaurus and the long-necked Limaysaurus.1

The first fossils of Campananeyen were found in 2016 but were not named until 2024, when scientists realized they belonged to a new species.1