Amphibians, Reptiles & Birds

Amphibia (frogs, salamanders, newts)

• The First vertebrates to colonize land

• Evolved from the Lobe-Finned Fish

• Have lungs that allow them to breathe air instead of water

• Limited to damp environments

Adaptations to Land• Fins became

strengthened to allow terrestrial locomotion

• Appearance of lungs, allowing them to breathe air

• Skin permeable to water, allowing some gas exchange underwater. They can also breathe through it.

• Have a three - chambered heart

Metamorphosis• Characterized by metamorphosis,

where the animal change its shape during its different life stages.– Stage 1: Larvae (Aquatic: A-D)– Stage 2: Adult (Semi-Aquatic: E-F)

Reproduction

•Reproduce via external fertilization and egg gestation, both requiring water.

Reptilia• Evolved from Amphibians• Includes extinct Dinosaurs,

and living lizards, snakes, turtles and crocodiles.

• Adapted to terrestrial land by having dry scales on their skin, and highly-developed lungs

Reptile Circulation• Reptiles have an advanced 4-chambered

heart• Mostly ectothermic, meaning their body

temperature is determined by their external environment.

Reptile Reproduction• Reproduce by

internal fertilization

• Oviparous– lay eggs with soft

water-resistant shells that do not require external water for development

– embryo protected by the amniotic membrane

Aves (Birds – or ARE they?.....)

• Believed to have evolved from the Dinosaurs

• Adapted for flight

• Bird feather may be a type of adapted reptile scale

Flight Adaptations• Feathers attached to

their skin • Bones are very light and

honey-combed in structure

Other Adaptations• Endothermic (control their own internal

temperature)• Have a 4-chambered heart (like reptiles &

mammals)• Have a Beak instead of teeth• Reproduce by internal fertilization and are

oviparous (eggs have hard, water-resistant shell)