The amphibians were the first tetrapod vertebrate animals to exist. They have limbs for walking on land (a vast improvement over the fish), as well as lungs for taking in oxygen from the air (another improvement). However, later animals of this class evolved very smooth skin, so they had to enter the water for short periods of time. Having been descended from lobe-finned fish in the Devonian, the amphibians started improving quicker than most animals at the time, and just became ferocious predators a million years after they came into the scene. As time would pass, the amphibians would evolve into yet another group of animals: the reptiles.
Amphibians Throughout Time (note that those are not all the ones that exist)Edit