Chordates

Chordata

Animals that have a stiff rod or cord running down back which changes to a backbone called spinal columns or vertebrae overtime

Classes Under Chordata

• Fishes

• Mammals

• Reptiles

• Birds

• Amphibians

Chordate Structures

• Backbone

• Endoskeleton

• Large brain

• Advanced nervous system

• Complex heart and circulatory system

• One or two pairs of appendages

• Special kind of outer covering

Fish Class

• Lampreys

• Shark, ray, and skate

• Bony/true fishes

Fish Characteristics

• Skeleton of bones covered with scales

• Fins

• Gills

• Two-chambered hearts

• Coldblooded

Lampreys

• Parasitic

• Circular mouth with teeth on tongues

• Destroys human food

Sharks, Skates, and Rays

• Sharks are not true fishes

• No scales or bones in skeleton

• Skeleton made of cartilage

• No flap of skin covering gills

• 5-7 rows of slits

• Cannot rest

Cartilage

• A tough tissue that bends easily

• Skeleton of sharks

True/Bony Fishes

• Fins stabilize movement and changes direction

• Swim bladder

• Obtain oxygen by gulping water and passing them over gills

• Oxygen passed into blood vessels through osmosis

• Cold Blooded

Swim Bladder

A gas filled bag that allows fishes to go to deeper water

Amphibian Characteristics

• Gills in tadpole

• Lungs in adult

• Three-chambered hearts (adults)

• Cold blooded

• Smooth, thin skin

• Two legs in tadpole

• Four legs in adults

• Frogs, toads, salamanders

Amphibian Growth

Tadpoles undergoes metamorphosis to become adults

Reptile Characteristics

• Lungs

• Scaly, dry skin

• Internal fertilization

• 3-4 chambered heart

• Cold blooded

• Limbs (except for snakes)

• Alligators, snakes, lizards

Reptile Facts

• First kind of animal to live whole life on land

• Internal fertilization and protected eggs

• A leathery shell produced by female covers fertilized eggs

Bird Characteristics

• Wings

• Hollow bones

• External eggs

• Feathers

• Four-chambered hearts

• Warmblooded

• Two legs

• Beak

Bird Facts

• Large powerful breast muscles for flight

• 2 layers of feathers

• Muscles to produce heat

• No teeth

• Beak shows type of food bird eats

• Eggs must be kept warm of at least 34c

2 Layers of Feathers in Birds

1. Down Feathers: small feathers under outer layer

2. Feathers we see

Mammal Characteristics

• Mammary Glands

• Young born alive

• Four-chambered hearts

• Warmblooded

• Intelligent brain

• Covered by hair/fur

• Humans, monkeys, cows

Mammal Facts

• 2 major groups: with/without placenta

• Placental Mammals: highest form of life

• Placental Mammals provide great amount of parental care

Gestation Period

Baby’s development period in placenta

Placenta

• A bag inside mother where baby grows and develops

• Advantageous since the baby is born more fully developed