The researchers discovered that the two groups, which they have creatively dubbed "Type 1" and "Type 2" have different wear on their teeth, suggesting different diets and thus different ecological niches. Then, genetic analysis confirmed that the two types of killer whale belong to different populations.
The scientists compared the findings to how Darwin's finches adapted to fill unique ecological roles.
So what does this mean for the future of the North Atlantic killer whales? If Type 1 and Type 2 become separate species, they would require separate conservation monitoring efforts.
And if that happens, hopefully the powers that be will think of some catchier names for them.