Phylum ChordataPhylum Chordata

Characteristics of Characteristics of ChordatesChordates

►NotochordNotochord►Dorsal nerve cordDorsal nerve cord► Pharyngeal pouches or gill slitsPharyngeal pouches or gill slits► Postanal tailPostanal tail

► Subphylum Subphylum CephalocharodatCephalocharodata- a- This subphylum This subphylum is composed of is composed of about 2 dozen about 2 dozen blade-shaped blade-shaped animals known as animals known as lancelets. They lancelets. They retain all retain all characteristic characteristic throughout life.throughout life.

► Subphylum Subphylum Urochordata- Urochordata- This This subphylum is subphylum is commonly known as commonly known as tunicates ( sea tunicates ( sea squirts). Larva squirts). Larva posses all chordate posses all chordate characteristics while characteristics while adults exhibit only adults exhibit only Pharyngeal pouches.Pharyngeal pouches.

Subphylum VertebrataSubphylum Vertebrata

►All characteristics All characteristics of chordatesof chordates

►Distinguishing Distinguishing characteristicscharacteristics Vertebral column Vertebral column

or spineor spine Cranium or skull Cranium or skull

that protects the that protects the brainbrain

Endoskeleton Endoskeleton composed of bone composed of bone or cartilageor cartilage

Major groups of Major groups of VertebratesVertebrates

Lampreys and HagfishesLampreys and Hagfishes

► Long, eel-like bodiesLong, eel-like bodies► Lack jawsLack jaws► Paired finsPaired fins► bonesbones

Sharks, Skates and RaysSharks, Skates and Rays

►Class Class ChondrichthyChondrichthyeses JawsJaws Paired finsPaired fins Skeleton of Skeleton of

cartilagecartilage

Boney FishesBoney Fishes

►Class Class OsteichthyesOsteichthyes JawsJaws Most have a Most have a

skeleton skeleton composed of composed of bonebone

AmphibiansAmphibians►Class AmphibiaClass Amphibia

Included frogs, Included frogs, toads and toads and salamanderssalamanders

Skin is moist and Skin is moist and permeable to gases permeable to gases and waterand water

Most lay eggs in Most lay eggs in waterwater

Most have an Most have an aquatic larval stageaquatic larval stage

ReptilesReptiles

►Class ReptiliaClass Reptilia Turtles, Turtles,

crocodiles, crocodiles, alligators, alligators, lizards and lizards and snakessnakes

Skin is dry and Skin is dry and scalyscaly

Eggs that can Eggs that can be laid on landbe laid on land

BirdsBirds

►Class AvesClass Aves Adapted for Adapted for

flightflight►FeathersFeathers►Hollow bonesHollow bones►Unique Unique respiratory respiratory systemsystem

MammalsMammals►CharacteristicsCharacteristics

EndothermyEndothermy HairHair Completely divided four chamber Completely divided four chamber

heartheart Milk produced from mammary glandMilk produced from mammary gland Single jawboneSingle jawbone Specialized teethSpecialized teeth

Order MonotremataOrder Monotremata

►Egg-laying mammalsEgg-laying mammals►Most primitive of mammalsMost primitive of mammals►Only three speciesOnly three species

Two anteaters and one platypusTwo anteaters and one platypus

Order MarsupialiaOrder Marsupialia

►250 species250 species►The U.S. has only one species – the The U.S. has only one species – the

Virginia opossumVirginia opossum►Young develop in a pouchYoung develop in a pouch

Placental MammalsPlacental Mammals

►Diverse group composed of at least 18 Diverse group composed of at least 18 ordersorders

►95% of mammals are placental95% of mammals are placental►They live on land, in water and the airThey live on land, in water and the air