Researchers in Australia have discovered that dolphin colonies living around Melbourne are a species unlike any other in the world, they revealed on Thursday.

Researchers in Australia have discovered that dolphin colonies living around Melbourne are a species unlike any other in the world, they revealed on Thursday

The dolphins that frolic in Port Phillip Bay and the Gippsland Lakes, numbering around 150, were originally thought to be one of the two recognised bottlenose species.

But Monash University PhD researcher Kate Charlton-Robb found they were different by comparing skulls, DNA and physical traits with specimens dating back to the early 1900s.

She has named them Tursiops australis, although they will commonly be known as the Burrunan dolphin, an Aboriginal name meaning large sea fish of the porpoise kind.

"This is an incredibly fascinating discovery as there have only been three new dolphin species formally described and recognised since the late 1800s," Charlton-Robb said of her research, published in the PLoS One journal.

"What makes this even more exciting is this dolphin species has been living right under our noses, with only two known resident populations living in Port Phillip Bay and the Gippsland Lakes in Victoria state."

The research relied in part on the analysis of dolphin skulls collected and maintained by museums over the last century, particularly holdings at Museum Victoria.