Chordata
Chordates are animals possessing a notochord, or the start of what may become a spine, a hollow dorsal nerve cord, which may contribute to a spine, pharyngeal slits, and a post-anal tail for at least some period of their life cycles. The phylum includes mammals(mammalia), bony fish (Osteichthes), and birds (aves). Humans are from this Phylum as well as the world's largest animal (the blue whale) and fastest animal (peregrine falcon) making this the most diverse phylum.
Aves
Birds lack teeth and the jaws are covered by a horn-like beak. Bird bones are hollow and filled with extensions of the body's air sacs. These air sacs allow for more oxygen to be used for flight. The hollow bones are thin-walled, but resistant to stress from bending that is involved in flight.
Osteichthes
Bony fish have a relatively normal pattern of bones in their skeleton. The head and pectoral girdles("shoulder" of the fish) are covered with large dermal bones. The Spine, skull, jaw, and ribs make up a bony fish's skeleton.
Mammalia
The basic plan of the skeleton for mammals is fairly universal. It consists of a head at one end of a spine, which ribs extend from to support the working organs and four limbs for movement. The spine usually ends in a tail. The huge range of lifestyles and habitats mammals live in means there is a great deal of variety that exists between different groups. Some species lack a tail, such as humans, others lack apparent hind limbs, such as the blue whale, and the skull can be different.