Now, scientists have confirmed that the animal represents a previously unknown species — and that several specimens, including a skeleton that hangs in the gymnasium of an Alaskan high school, share similar DNA.
The whale also matches the DNA of three animals found beached in Japan in 2013. Those results had made researchers suspect a new species, but they felt more evidence was needed before the find was made official. Tissues taken from the Unalaska High School specimen (which was found dead in 2004) and research collections in the area show that these black whales have much more in common with one another genetically than any of them do with previously known species of beaked whale.
These could be the remains of a small, rarely seen black whale known as karasu, or raven, among Japanese sailors. But experts have never gotten to examine one of these creatures in life, and they've never been considered a unique species. Those who did see the small whales usually lumped them in with the similar-looking Baird's whales, assuming they were young or dwarfed individuals with unusual coloring.
It seems likely that these karasu are indeed members of the newly discovered species. But until scientists can observe them closely enough to note their characteristics and sample their DNA, the new kind of whale is known only by bones and a few bloated corpses.
"We don't know how many there are, where they're typically found, anything," Phillip Morin, a molecular geneticist at the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center and lead author of a study on the new species published on Tuesday, told National Geographic. "But we're going to start looking."
There are only 22 other known species of beaked whales in the world, and just two of them swim in the Pacific. Like those two whales, the new, as-yet-unnamed creature has been placed in the genus Berardius. But it doesn't look much like even its closest cousins. An adult specimen of the new species is just two-thirds the size of an adult Baird's beaked whale, and its fin and beak are shaped strangely. Then there is its distinctive dark color and the myriad genetic differences that set it apart as separate species.
The Japanese researchers who presented the first evidence on the new species back in 2013 are reportedly working on a formal description so that the animal can be added to the scientific literature.
"They're going to try and get pictures of it. It spawns a lot of new research. That's exciting," Morin told CBC news.
Morin and his colleagues hope that the species can be properly identified and protected. Beaked whales are private creatures, diving deep to feed and rarely spending much time where humans might see them. But until scientists determine exactly where the beaked whales reside and how numerous they are, they can't be sure that the newly discovered species is safe from extinction.
"It boggles my mind to think that a large, very different-looking whale has gone unnoticed by the scientific community for so long," Robert Pitman of the Society for Marine Mammalogy, who wasn't involved in the study, told National Geographic. "It sends a clear message about how little we know about what is in the ocean around us."