Amphibians are vertebrates that spend their lives in both water and land. They’re ectothermic and have complex nervous and circulatory systems. Amphibians reproduce sexually, and they lay their eggs in the water. Eggs hatch into larvae with long tails that allow them to swim in the water. Amphibians are divided into three orders: frogs and toads, salamanders and newts, and caecilians. All amphibians are descendants of the lobe-finned fish.
Amphibian: Vertebrate that lives in both land and water.
Keratin: A tough protein in the skin, feathers, nails, and other parts of tetrapod vertebrates.
Tetrapod: Vertebrate with 4 limbs.
Ectothermy: Body temperature is controlled from the outside through behavioral changes such as basking in the sun.
Cloaca: Body cavity that stores waste/gametes and has an opening that allows them to leave the body.
3 orders of amphibians: