Amphibian facts for kids: 4 amphibians to research

Amphibians were the first vertebrates to live on land, around 370 million years ago, and the more than 8,000 living species — frogs and toads, salamanders and newts, and the legless caecilians — still lead a double life. Most hatch in water as gilled larvae, tadpoles in the case of frogs, then change body shape to breathe air and live on land; the axolotl is the exception that keeps its gills for life. Their thin, moist skin takes in water and oxygen, which is why they stay close to damp places and why they are so sensitive to pollution and disease. Poison dart frogs turn that skin into a warning, storing toxins from the ants and mites they eat under bright colours. Salamanders can regrow lost legs and tails, and the Chinese giant salamander reaches 1.8 metres. Amphibians are the most threatened class of vertebrates: around 40% of species are at risk, and the chytrid fungus has driven dozens of frog species to extinction.