They were doing field work in the waters near Kauai when they spotted a pod of melon-headed whales and rough-toothed dolphins swimming alongside each other.
The male "wholphin", which is believed to be close to adult age, was spotted swimming with dolphins near the island of Kauai past year, according to Dr Robin Baird, the marine biologist who headed the expedition.
The researchers told CBS News that the animal's father was a rough-toothed dolphin and the mother a melon-headed whale.
Before you go tie your head in knots wondering how a whale managed to successfully reproduce with a dolphin - it didn't.
While some news organization have described the melon-headed whale and rough-toothed dolphin hybrid as a new species, in order for that to happen other things need to occur, including more widespread hybridization, Baird said.More news: Polar bear killed after attack on Arctic cruise ship guard
Both pigmentation and morphological characteristics suggested it may be a hybrid resulting from a melon-headed whale and a rough-toothed dolphin mating, scientists explained in the new report.
They were able to take a sample for a biopsy, which confirmed their suspicions.
A good example of hybridisation leading to a new species is the finches of Galapagos, where scientists recently observed finches becoming a new species in just two generations.
However, he's not he first dolphin hybrid from the wild, with researchers noting he was the third known case of the Delphinidae family partnering up outside their species. Soon after, they were able to get DNA, which led them to the definitive conclusion that it was indeed a hybrid of the two species.
Although many reports have called the wholphin a brand new species, in reality, this isn't the first time a whale/dolphin hybrid has been found. Rough-toothed dolphins, on the other hand, prefer to stay in ones or twos. "And to know she has cousins out there in the ocean is an fantastic thing to know". "I wouldn't be surprised if there are more hybrids between the two species ― they do associate quite regularly".More news: Mainz confirm Newcastle move for Muto
A mule, for instance, is a hybrid between a male donkey and a female horse.
"It increases their ability to understand not only how species are using the range, but what effects Navy sonar may have on them", Baird says.
A likely scenario for how the hybrid came to be a melon-headed whale getting separated from its group and ending up travelling with rough-toothed dolphins.
It's unknown whether this new animal - which the researchers named Steno bredanensis - could produce viable offspring, but in any case, one hybrid animal does not make a new species. Wholphins have also been conceived in captivity with the last one at Sea Life Park in Hawaii.
This latest hybrid animal is not the first to be branded with the "wholfin" name.More news: California wildfires: Six killed as hundreds of homes destroyed