A ratite is any of a diverse group of large, flightless birds of Gondwanan origin, most of them now extinct. There is still some controversy regarding the systematics involved. Some sources state that Ratites are synonymous with *Struthioiniformes*, while other sources state that Ratites are the same group, only that the order *Struthioniformes* contains only the Ostrich and possibly the Elephant Bird. Unlike other flightless birds, the ratites have no keel on their sternum - hence the name from the Latin ratis (for raft). Without this to anchor their wing muscles, they could not fly even if they were to develop suitable wings.