Return to Vertebrata (thing)
Members of Subphylum Vertebrata make up most of [Chordata|Phylum Chordata]. They share all of the characteristics of that [phylum] (including a [notochord], [dorsal hollow nerve cord], [pharyngeal slits], and a [postanal tail]), but have their own distinct characteristics that seperate them from the other two subphyla, [Cephalochordata] and [Urochordata]. They have a [neural crest] that forms during [embryonic development], near the [neural tube]--this is also associated with pronounced [cephalization] (the concentration of sensory and neural equipment in the head). Vertebrata receive their name from the [vertebral column] they all share--a [spinal cord] made up of seperate bones or pieces of [cartilage]. It is also important that Vertebrates have a [closed circulatory system].
Vertebrates are divided into two superclasses. [Agnatha|Superclass Agnatha] contains all [jawless vertebrates]--it is divided into [Myxini|Class Myxini] (hagfishes) and [Cephalaspidomorphi|Class Cephalaspidomorphi] (lampreys). [Gnathostomata|Superclass Gnathostomata] contains most animals normally associated with vertebrates--all of them have [hinged jaws]. It itself is divided into [Chondrichthyes|Class Chondrichthyes] (cartilaginous fishes, e.g. sharks and rays), [Osteichthyes|Class Osteichthyes] (bony fishes, e.g. bass and tuna), [Amphibia|Class Amphibia] (amphibians, e.g. salamanders and frogs), [Reptilia|Class Reptilia] (reptiles, e.g. snakes and lizards), [Aves|Class Aves] (birds, e.g. owls and eagles), and [Mammalia|Class Mammalia] (mammals, e.g. koalas, platypuses, bats, and [humans]).