Chordata Aubrey Irwin

Agnatha Oldest Class of Vertebrates* Jaw-less animals Cylinder, eel-shaped body The notochord persists in the adult The skeleton is composed of cartilage Example: Lampreys

Chondrichthyes Cartilaginous fish Skeletons made of cartilage Internal jaws are present Paired appendages Three semicircular canals Example: Sharks

Osteichthyes Bony fish Skeletons made of bone Operculum (a flap on each side of the head that covers the gills). The movements of these flaps allow the fish to breathe without moving. Most bony fish are carnivorous, few are herbivores that feed on algae and aquatic plants, and some are filter feeders Example: Ray-finned fish

Amphibia 1st vertebrates adapted to live both on land and water Reproduce in water or moist land Glandular skin that lacks the keratinized scales Most have complex life cycles Surrounded by several gelatinous layers Example: Salamanders

Reptilia Able to retain moisture Live on land Produce eggs that do not have to develop in water Improved Skelenton Shelled eggs Scaly skin Examples: Turtles

Aves Birds Presence of feathers Appendages modified as wings High metabolic rate Bones that are lightened by numerous air spaces

Mammalia Have hair/fur Mammary glands Three middle ear bones Warm Blooded Lungs are present Example: Tigers

Three Groups Vertebrates Tunicates Lancelets

Overview/Characteristics All have tails, hollow nerve cord, notochord, and pharyngeal slits at some point of life or development.

Vertebrates Large Active Well developed brains in hard skull Segmented backbone Example: Humans

Tunicates Urochordates Free swimming/sessile Example: Sea squirts

Lancelets Cephalochordates Small Eel-like Found in shallow tropical oceans Example:Lancelet