Researchers have identified a new humpback dolphin species off northern Australia, using genetic mapping to single out an animal not previously known to science. A global team led by the US-based Wildlife Conservation Society made the discovery after examining almost 200 dead dolphins and tissue specimens from live animals across the four Atlantic, Indian and Indo-Pacific ocean areas where humpbacks are known to live. A study of the beak length and number of teeth in 180 skulls from beached and museum specimens, as well as live DNA samples from 235 dolphins, identified a new species in the humpback, or sousa genus, which frequents waters off northern Australia. \"Based on our combined genetic and morphological analyses, there is convincing evidence for at least four species within the genus,\" lead author Martin Mendez wrote in the paper, published in the latest edition of the journal Molecular Ecology, adding that this included \"a new as-yet-unnamed species off northern Australia\". The Wildlife Conservation Society said it was a significant finding -- identifying a new mammal species is rare -- and that it hoped it would boost conservation efforts. Two of the three already-identified sousa species are in decline and considered at risk from habitat loss and fishing, with S. chinensis, found in the eastern Indian and West Pacific Oceans, listed as near-threatened by the International Union for Conservation of Nature. S. teuszii, which lives in the Atlantic off West Africa, is rated vulnerable. \"This discovery helps our understanding of the evolutionary history of this group and informs conservation policies to help safeguard each of the species,\" said Mendez. The team\'s findings will be used to formally apply for a new species to be named by the International Commission on Zoological Nomenclature.   Humpback dolphins are so named due to a distinctive hump just below their dorsal fin, which is also uniquely elongated.