A large, diverse, worldwide order of shore and aquatic birds found from dry plains to the open ocean, and from the tropics to the high latitudes. Charadriiformes may be closely related to the pigeons (Columbiformes) on the one side and to the cranes, rails, and their allies (Gruiformes) on the other. The sandgrouse, here included in the Columbiformes, are sometimes placed in the Charadriiformes. Some workers place the flamingos (Phoenicopteriformes) and the ibises (Threskionithidae; Ciconiiformes) in this order, but these decisions are highly controversial.