Palaeognathae is a clade of birds that includes species such as ostriches, emus, and kiwis. These birds are characterized by their unique skeletal structure, particularly their palate, which is different from that of most other birds. Palaeognathae are primarily flightless and are found in various regions around the world. Members of Palaeognathae are generally large and have strong legs adapted for running. They often have a more primitive anatomy compared to other birds, which is why they are sometimes referred to as "ratite" birds. This group plays an important role in understanding the evolution of birds.