The superclass Tetrapoda (Ancient Greek τετραπόδηs tetrapodēs, "four-footed"), or the tetrapods /ˈtɛtrəpɒd/, comprises the first four-limbed vertebrates and their descendants, including the living and extinct amphibians, reptiles, mammals, birds, and some extinct fish. Tetrapods evolved from the lobe-finned fishes around 390 million years ago in the middle Devonian Period, with modern tetrapod groups having appeared by the late Devonian, 367.5 million years ago.