Class Mammalia (mamma, mammil = teat, nipple) is the mammals. But the phylum Chordata also has other two subphyla, called the Urochordata and Cephalaochordata. Mammals have a diaphragm to aid in respiration. Vertebrates are further differentiated from chordates by their vertebral column, which forms when their notochord develops into the column of bony vertebrae separated by discs. In some chordates, the notochord acts as the primary axial support of the body throughout the animal’s lifetime. As chordates, vertebrates have the same common features: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail. These are invertebrate animals but show some distinguishing attributes of Chordates, like the presence of notochord. There are several classes of chordates, including, fish, birds, reptiles, mammals … Epidermis has numer­ous unicellular gland cells which secrete … Note: not all chordates have these features, but it is believed that their absence in some chordates is secondary. Let’s take a tour of the five main vertebrate groups alive today: the fishes, amphibians, reptiles, birds, and mammals. There are many different animal classes and every animal in the world belongs to one of them. The vertebrate has a distinct head, with a differentiated brain and three pairs of sense organs (nasal, optic, and otic [hearing]). Most mammals bear live young. The five most well known classes of vertebrates (animals with backbones) are … 1. Protochordata: In Branchiostoma the skin is simple without keratin. The notochord acts as support during movement by stiffening the body and lies ventral to the central nervous system and dorsal to the gut. In vertebrates, the notochord is present during embryonic development, at which time it induces the development of the neural tube and serves as a support for the developing embryonic body. They are endothermic. The epidermis is single layered made of tall or columnar cells. Several groups of vertebrates inhabit planet Earth. The body is divided into trunk and tail regions. Key characteristics of mammals are the presence of fur/hair and mammary glands, derived from modified sweat glands, which produce milk for the young. Scientists have grouped animals into classes to make it easier to study them. The notochord, however, is not found in the postnatal stage of vertebrates; at … Chordates are organisms that, at some time during their development, possess a rod called a notochord extending the length of their bodies at full development. Most chordates have a complete digestive tract, and a body cavity. ADVERTISEMENTS: The fundamental structure of skin in all the vertebrates is the same but there are certain variations in different classes. And hence, we can say that all vertebrates are chordates, but not all chordates are vertebrates. These are ciliated in Balanoglossus. This is a great study tool for anyone learning the 7 levels and the 5 chordata Mnemonic device for remembering the following: 7 LEVELS OF CLASSIFICATION KINGDOM PHYLUM CLASS ORDER FAMILY GENUS SPECIES 5 CLASSES OF CHORDATA AGNATHA AVES MAMMALS CHODRICHTHYES OSTIEICHTYES AMPHIBIAN REPTILE