It’s not every day a new species of butterfly is discovered—and it’s even less common for that species to have been hiding in plain sight all along. One lepidopterist’s sharp eye has revealed an entirely new species of Alaskan butterfly, something that hasn’t been discovered in 28 years.

The lepidopterist in question is Andrew Warren, the senior collections manager at the Florida Museum of Natural History’s McGuire Center for Lepidoptera and Biodiversity. Warren, who dubs himself “AndyBugGuy” on Twitter, has also been called “Lord of the Butterflies” for his dominion over the gigantic 10-million specimen collection at the McGuire Center.

What Warren and his colleagues didn’t realize was that an entirely new type of butterfly was hiding in plain sight at the Center. One day, Warren was working with his collections when he noticed something off about a butterfly that had been categorized as O. chryxus, a rare Arctic butterfly most commonly spotted in the Rockies. This butterfly, which had been in the same collection for 60 years, didn’t look the same at all—it was bigger and darker, and had been collected near Tok in southeastern Alaska.

Warren sprung into action, working with colleagues to review the appearance of the butterfly and corroborate his find in Alaska. The team found a large number of additional specimens in private collections and at the University of Alaska’s Kenelm Philip collection, too.

It makes sense that the species was categorized as O. chryxus—it looks a lot like that butterfly. But it is also similar to O. bore, the white-veined Arctic, and there could be an intriguing reason: Warren and his team think that the butterfly is a hybrid of both species. In the past, both species could have mated and produced the new species.

Yet over time, O. chryxus and O. bore moved further and further apart. As the last age cooled down Beringia—a strip of land between Alaska and Asia that never became glaciated—the butterfly-friendly area became less hospitable. It appears that O. chryxus moved south to the Rockies and O. bore stayed in Beringia alongside the new species.

Looks aren’t the only thing that matters—the new species also shares mitochondrial DNA with O. bore. Next, Warren and his team want to sequence the new butterfly’s genome to figure out if it is indeed a hybrid and figure out why it was able to survive in the much harsher Arctic.

For now, they’ve named the new butterfly Oeneis tanana—the Tanana Arctic butterfly and published the results of their work in the Journal of Research on the Lepidoptera. With wings the color of a penny, large white specks on its underwings and a “frosty” look appropriate for the Arctic, the Tanana Arctic could be the only butterfly endemic to the Alaska’s Last Frontier.

Warren will head out to the Yukon-Tanana basin next year to look for the species in the wild. Who knows what else he might notice that others have missed?