SBI 3U

Phylum Chordata (Part 2)

Invertebrates: urochordata and lancelets only notochord and nerve cord

Vertebrates: largest group of chordates. Notochord backbone. Nerve cord spinal cord

Subphyla: Vertebrates vs. Invertebrates

AgnathaChondrichthyesOsteichthyesAmphibiaReptiliaAves

Superclasses of Invertebrates

Lampreys & hagfishSlimy skin & lack paired finsSkeleton made up of cartilageLampreys external parasitesHagfish scavengers

Superclass: AgnathaJawless Fishes

Sharks, skates and raysCartilaginous skeletonBiting jaws & paired finsShark successful animal. Streamlined body

and fins enhance stability

Superclass: ChondrichthyesCartilaginous Fish

Most numerous vertebratesMany kinds: trout, salmon, cod, perch, sole,

eel, halibut & tunaAll have gills Body covered with flat, flexible scalesBlood pumped through a 2-chambered heart

Superclass: OsteichthyesBony Fish

Two lives – not literally!Spend early part of life in water and rest on

moist habitat

Superclass: AmphibiansFrogs, Toads & Salamanders

Crocodiles, alligators, turtles, tortoises, lizards and snakes

Thrive in terrestrial environment and some moved into arid regions

Developed a tough skin that restricts water loss and kidneys that can excrete highly concentrated urine to conserve water

Superclass: Reptilia

Scales on legs, large-yolked eggs Generate their own body heat and maintain a

high, relatively constant body temperatureFeathersHollow bones

Superclass AvesBirds

Body covering of hairFour chambered heartSpecialized teethMammary glands

Superclass: Mammalia