Unique Traits of Amphibians

During the Devonian time period, sarcopterygian fish, which had lungs and bony-limbed fins, evolved into the first amphibians. They flourished during the Carboniferous and Permian epochs, when they were at the height of their power, but were eventually overtaken by reptiles and other animals. There has been much debate over where modern amphibians, the Lissamphibia, first appeared (approximately 250 million years ago in the Early Triassic). New evidence suggests, however, that they descended from the Permian era's temnospondyls, the most diversified group of extinct amphibians. Anura (the frogs), Urodela (the salamanders), and Apoda (the caecilians) are the three living orders of amphibians. The Albanerpetontidae family, the fourth, went extinct about 2 million years ago. About 8,000 species of amphibians have been identified, with frogs making up nearly 90% of that total. The New Guinean frog (Paedophryne amauensis) is the tiniest amphibian (and vertebrate) in the world, measuring in at a mere 7.7 mm (0.30 in) in length. The South China giant salamander (Andrias sligoi) is the largest living amphibian at 1.8 m (5 ft 11 in) in length, although extinct temnospondyls like Mastodonsaurus, which could grow to be 6 m (20 ft) in length, were much larger. Herpetology encompasses both batrachology (the study of amphibians) and ichthyology (the study of reptiles and amphibians).