Scientists have officially revealed the Australian humpback dolphin as a new species, according to the Wildlife Conservation Society and Clymene Enterprises.
The unveiling follows 17 years of systematic examination of all available historical records, physical descriptions and genetic data of humpback dolphins - a widespread group of coastal cetaceans ranging from the coast of West Africa to the northern coast of Australia.
The Australian humpback dolphin (Sousa sahulensis) is now the fourth recognized humpback dolphin species.
"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," co-author Dr. Thomas Jefferson said in a statement.
"The formal recognition and naming of a new species brings with it a need to formulate or update plans for protection of these dolphins," added Dr. Howard Rosenbaum of the Wildlife Conservation Society.
These marine animals are threatened with fisheries interactions, collisions with vessels and loss of habitat due to coastal developments.
These humpback dolphins in particular have vexed taxonomists for decades until researchers from the Wildlife Conservation Society and a number of other institutions provided the most definitive results in late 2013.
In recent years, scientists have debated whether all humpback dolphins should be considered the same species, or if they should consider the nine kinds of known dolphins as separate subspecies.
The new study contains detailed reviews and descriptions of the currently recognized four humpback dolphin species, using external and skeletal measurements, coloration, molecular genetics and geographic distribution. It builds upon previous research that first discovered the Australian humpback dolphin, found in waters off northern Australia and the island of New Guinea.
Other species closely related to it are the Atlantic humpback dolphin (Sousa teuszii), the Indo-Pacific humpback dolphin (Sousa chinensis) and the Indian Ocean humpback dolphin (Sousa plumbea).
A description of this new species was published in the journal Marine Mammal Science.