ECHINODERMATA, Hemichordata, Chordata.Arthropoda is the largest phylum of Animalia.Arthropoda INCLUDES insects.Explanation-One of the distinguishing features of arthropods is the presence of a tough, chitinous exoskeleton.Chitinous exoskeleton called cuticle which covers the entire body surface.The cuticle is a PRODUCT of the secretion of the underlying epidermis.The cuticle is made up of CHITIN, protein, and lipid.The cuticle is generally thick and rigid.The chitinous exoskeleton is shed periodically to permit the growth of the body.Therefore chitinous exoskeleton occurs in insects.BirdsAll types of BIRDS are included in this class.Birds are warm-blooded.The characteristic of birds is the presence of feathers all over the body.Birds are also known as ''feathered bipeds''.FishesThe Devonian period is called the Golden period of fishes.They are cold-blooded.They are aquatic, may be freshwater or marine.Baby fishes are called Fry or Hatchling.MammaliaCoenozoic era is golden era of animals.Mammals are warm-blooded.The body is divided into head, neck, trunk, and tail.Mammals are unisexual animals.