MAIN CHARACTERISTICS• They have got a spinal column or a internal esqueleton.• Their bodies are divided : head ,trunk and extremities.• Their nervous system and sense organs are very well developed .
FISH• Body covered with scales.• Breathe with gills• They use their fins to swim.
AMPHIBIANS• Young are aquatic animals with gills.• Have got smooth skin and lungs to breathe air when they become adults.• Also cutaneous respiration.• Oviparous animals.• Most are carnivores.• Main groups : Frogs and toads – salamanders and newts.
REPTILES• Have got hard scales and lungs to breathe air.• By crawling on four legs .• Snake are different because they haven´t got legs .
BIRDS• Birds have got feathers .Have got four extremities.Two wings and two wings.• All birds have got lungs.
MAMMALS• Have usually got some hair .• Have got lots of thick hair called fur.• Are oviparous• Are three groups..monotremes,marsupials and placental mammals.