Lungfishes are sarcopterygianfish that can breathe air (and in some species are obligate air_breathers), and have limb_like appendages instead of fins. There are six living species known; four in Africa, and one each in South America and Australia.
They all have an elongate body, four limbs, and a single rear fin.
Taxonomy
Taxonomy of lungfishes presents some difficulty because of their resemblances to both fish and land-dwelling vertebrates, and have been classified in a variety of ways, ranging from classDipnoi, to infraclassDipnomorpha, to orderDipteriformes. However, there is general agreement that there are two main subcategories, here given as orders:
Ceratodontiformes: characterized by having broad flipper_like fins and an unpaired lung.