Chordate Animals

Phylum Chordata

Phylum Chordata Notochord Gill slits Dorsal hollow nerve cord Post anal tail

Fish Gills Extract oxygen from water Fins for swimming

Lobed-Fins (Muscles)

Evolution of Amphibians

Transitional Tetrapods Skull, teeth, limbs similar to lobe-finned fish Acanthostega Ichthyostega

Amphibians Moist skin Must return to water to reproduce

Class Reptilia Scales Amniotic egg

Reptiles Peg like teeth

Reptiles First animals to live away from water

Amniotic Egg

Evolution of Placenta from Amniotic Egg Reptile Chorion Oxygen from air Amnion Provides private pond Yolk Sac Food for embryo Allantois Store urinary waste Mammal Chorion Form placenta to get oxygen & food from mothers blood Amnion Provides private pond Yolk sac Temporarily make RBCs Allantois Form umbilical cord

Birds Feathers No teeth Scales on legs Bones with air spaces

Adaptations for Flight Honey combed bones Air cavities Less weight

Light Weight Skeleton Frigate bird 7 foot wing span 4 ounce skeleton

Adaptations for Flight Enlarged sternum Flight muscle attachment Long neck balance

Migration Sissor-tailed flycatchar Migates to Central and South America in October Returns in April

Migration Arctic tern Migrates 25,000 miles!

Benefits of Birds to Man Eat insects, rodents and weeds Spread seeds for flowers and trees Food Sport Pets

Fastest Animal Peregrine falcon Strikes prey at 180 mph

Elephant Bird Eleven feet tall 1100 pounds Largest egg ever Extinct in late 1600’s

Caudipteryx Feathered dinosaur Flightless Transitional fossil Dinosaur arms Dinosaur teeth Only front of upper jaw Bird feathers

Archaeopteryx 147 MYA Transitional fossil Jurassic Period Characteristics of reptiles Characteristics of birds

Archeopteryx Reptile characteristics Bird characteristics Teeth Boney tail Fingers with claws Bird characteristics feathers

Class Mammalia Hair Mammary glands Sweat glands Specialized teeth

Reptile Ancestor Reptiles from Pennsylvanian and Permian 300-245 MYA Body close to ground Legs away from body Canine like teeth Dimetron

Early Mammals Triassic 220 MYA Small

Basic Mammal

Monotremes Lay eggs Incubate 12 days Lick milk from mothers fur Transitional species

Marsupials Pouched mammals Birth to tiny embryo Embryo attaches to mother’s nipple to complete development

Placental Mammals Placenta nourishes embryo Long gestation period 22 months for elephant Most successful group of mammals

Placental Mammals Competitive advantage over monotremes and marsupials Better nutrition from placenta Less vulnerable to predators More advanced at birth

The End