Scientists hoping to clear up the confusion in a taxonomically challenged collection of marine mammals say they've settled on a name for a species that's new to science; welcome, Sousa sahulensis.

Or if Latin is not your strong point, say hello to the Australian humpback dolphin.

It is now the fourth recognized species of humpback dolphin after researchers concluded a 17-year-long effort to examine historical records, recorded physical descriptions and genetic data on the group.

"We've finally managed to settle many long-standing questions about humpback dolphins -- particularly how many species actually exist -- using a huge body of data collected over two centuries and analyzed with the latest scientific tools," says Thomas A. Jefferson of Clymene Enterprises, who conducted the analysis with Howard C. Rosenbaum of the Wildlife Conservation Soceity.

A report of their work has been published in the journal Marine Mammal Science.

The naming of any new species demands a thorough and systematic examination of all the species that are most closely linked to the creature in question.

Humpback dolphins especially puzzled taxonomists and researchers for decades, with scientists in heated debates about how many distinct species might exist.

Some have postulated that all humpback dolphins are of one single species, while others have held that the number of distinct, different species could be as high as nine.

In the new study, exterior and skeletal dimensions, colors, genetic factors and geographic distribution allowed Jefferson and Rosenbaum to confirm the existence of the distinct humpback dolphin variety living in waters off northern Australia and around the island of New Guinea.

The new species joins three others; the Atlantic humpback dolphin, the Indo-Pacific humpback dolphin and the Indian Ocean humpback dolphin.

There are differences in appearance, the researchers report; the dorsal fin of the Australian species is lower with a wider base than those of the Atlantic and Indian Ocean dolphins, and its dark gray coloration sets it apart from the clearly distinctly white (sometimes with a tinge of pink) coloration of the closest geographic neighbor, the Pacific humpback dolphin.

While there is as of yet no way to make an estimate of the population of the Australian humpback dolphin, sighting data suggests it's unlikely there are more than just a few thousand of species living, the researchers say.

"Humpback dolphins throughout their range are threatened with fisheries interactions, vessel impacts, and development in their coastal habitats," says Rosenbaum. "Efforts to protect humpback dolphins and other coastal dolphins, and their most important habitats, are essential for the survival of these species."

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