They’ve feathers, their entrance limbs are formed like wings. It has no flake construction. They’re warm-blooded. There isn’t a gland of their pores and skin. Solely within the root of the tail are sebaceous glands. The mouth is on the tip of the keratin beak. It has no enamel. The skeleton is totally ossified. The bones are stuffed with air. Ribs are fairly small. The center has 4 chambers. Purple blood cells comprise nuclei. Respiratory takes place with the lungs. The within of the bones is hole and skinny. There are very mild hairs.
Lack of many pores and skin and glands. Lack of enamel and a heavy jaw. Lack of the tail vertebrae and a few joints. Particularly the formation of wider bones within the chest, hipbone and backbone as a result of fusion of the bones. Air sacs between the interior organs. The ovary is atrophied. They’ve quick digestion. The discharge residues are within the type of uric acid.