The kagu long posed a puzzle to those who sought to classify it. For a long time, it was believed to be a member of the Gruiformes, or crane-like birds. More recent studies have placed the kagu within its own class, Eurypygiformes, with the Central and South American sunbittern (second image). The kagu is also believed to be closely related to the now-extinct New Zealand adzebills (lowest image). This means that these birds likely came from a lineage that was dispersed with the splitting of the super-continent Gondwana.