Phylum Chordata The chordates
Five Chordate Hallmarks Notochord – flexible rodlike structure; extending length of body
Five Chordate Hallmarks Dorsal tubular nerve cord
Five Chordate Hallmarks Pharyngeal pouches and gill slits
Five Chordate Hallmarks Endostyle or thyroid gland – secretes mucous that traps food particles in pharyngeal cavity
Five Chordate Hallmarks Postanal tail – tail extends beyond anus
Sixth Chordate Feature Ventral Heart – heart located ventrally
Higher Classification of Chordata Phylum Chordata Subphylum Urochordata – tunicates, sea squirts Subphylum Urochordata – tunicates, sea squirts SubphylumCephalachordata – lancelets SubphylumCephalachordata – lancelets Subphlum Vertebrata- vertebrates Subphlum Vertebrata- vertebrates
Subphylum Urochordata Sea Squirts or Tunicates
Urochordate Characteristics Have a non-living tunic Most chordate features found in the free living acidian larva Adults sessile filter feeders
Acidean Larva and Metamorphosis
Adult Urochordate
Subphylum Cephalochordata Lancelets
Cephalochordate Characteristics Notochord and nerve cord found along entire length of body, persists throughout life Fish-like in form Includes the lancelets (amphioxus)
Amphioxus
Subphylum Vertebrata The Vertebrates
Vertebrate Characteristics Bony or cartilaginous vertebrae surrounding spinal cord Notochord only in embryonic stages, persisting in some fishes Two superclasses according to presence of jaws
Vertebrate Higher Classification Superclass Agnatha - without jaws Class Myxini – hagfishes Class Myxini – hagfishes Class Cephalaspidomorphi – lampreys Class Cephalaspidomorphi – lampreys Superclass Gnathostomata – with jaws Class Chondrichthyes – sharks, rays, chimaeras Class Chondrichthyes – sharks, rays, chimaeras Class Actinopterygii – ray-finned fishes Class Actinopterygii – ray-finned fishes Class Sarcopterygii – lobe-fin fishes Class Sarcopterygii – lobe-fin fishes Class Amphibia – frogs, salamanders Class Amphibia – frogs, salamanders Class Reptilia – snakes, lizards, crocodiles Class Reptilia – snakes, lizards, crocodiles Class Aves - birds Class Aves - birds Class Mammalia - mammals Class Mammalia - mammals