Scientists Just Dissected the World’s Rarest Whale in New Zealand. Here’s What They Found

When a 16-foot, 3,000-pound mystery whale washed ashore on the South Island of New Zealand in July, even the world’s foremost cetacean experts were taken aback.

Anton van Helden, a senior marine science adviser for New Zealand’s Department of Conservation, first saw a picture of the whale come across his phone while he was sitting on his couch, recovering from surgery. He had no doubt about what it was.

“I immediately went, ‘Oh my goodness, it’s a spade-toothed whale!’” van Helden tells CNN’s Lex Harvey. “A lot of people didn’t believe me.”

Van Helden’s assessment turned out to be correct. The “stocky, powerful-looking little animal”—as he describes the creature to CNN—was indeed a spade-toothed whale. The carcass was in remarkably good condition and appeared in a region of New Zealand that allowed researchers to perform the first-ever dissection of the species.

But any initial disbelief from scientists was warranted: The spade-toothed species, part of the beaked whale family, is considered the rarest whale on Earth. Before now, it had only been spotted by humans six times—never alive and never in the correct conditions for dissection. A 2012 study suggested the whales are “exceptionally deep divers” that dwell far below the surface of the South Pacific Ocean.

“It’s very hard to do research on marine mammals if you don’t see them at sea,” Hannah Hendriks, a marine technical adviser for the Department of Conservation, told Charlotte Graham-McLay of the Associated Press (AP) after the initial discovery in July. “It’s a bit of a needle in a haystack. You don’t know where to look.”

Much of the existing knowledge of the species was based on lower jaw and tooth samples collected on Pitt Island, 500 miles west of mainland New Zealand, in 1874, as well as partial remains found decades later. When specimens washed up in 2010 and 2017 on the North Islands, scientists could only undertake minimally invasive sampling—and no dissection—before the whales were buried.

This time, however, the research and dissection process, which began last week, was under the guidance of both scientists and members of local Māori tribes on the South Island. It aimed at elucidating both biological and cultural knowledge of the whale, known as a taonga, or sacred treasure, to the Māori people.

Rarest whale in the world undergoes dissection.

Mana whenua and scientists are examining the rarest whale in the world for the first time ever.

Find out more: https://t.co/Ssn0oTOFiG pic.twitter.com/E2gKP1mrPz

— Department of Conservation (@docgovtnz) December 3, 2024

As van Helden tells Eva Corlett of the Guardian, “We’re working around a dead animal, but it’s telling us about how it [lived], and also that’s unpacking all of the life stories of the people involved around it.”

“Not only was this tohorā (whale) the first of its kind to be dissected by science, but it was also the first time our hapū (subtribe) worked with scientists to pull together Indigenous and Western knowledge systems so we can all gain a better understanding of the whale and its behaviors,” Rachel Wesley, a representative in the regional tribal government, says in a statement from the Department of Conservation.

Initial findings from the extensive dissection offer the researchers new clues in understanding how spade-toothed whales live—as well as how this specific one died.

One point of interest was the discovery of small vestigial teeth in the whale’s upper jaw. In a study of other beaked whale species, researchers determined that vestigial teeth receded as evolution favored “suction feeding, primarily on squid.”

“These little teeth embedded in the gum tells us something about their evolutionary history,” van Helden says in the Department of Conservation statement. “It’s just another thing that we had no idea about.”

So too was the discovery of nine stomach chambers in the spade-toothed whale, some of which contained “squid beaks and some lenses from the eyes of squid, a few parasitic worms and maybe some other parts of organisms that we are not quite sure of,” van Helden says in the statement, confirming the importance of squid in the whale’s diet.

As research on the whale continues—from new measurements to a CT scan of its head—more details will come into sharper focus.

“We also found interesting structures associated with both feeding and sound production. Weights and measurements and descriptions were made of various muscles and organs, to help us describe this species and make comparisons with related species,” van Helden adds in the statement. “These all add to the body of knowledge we are building.”

As for this specific individual, researchers believe that bruising around the head and a broken jaw indicate head trauma was the cause of death.

Even as the dissection ends, the whale will have many scientific and cultural afterlives. Following the dissection, the local iwi, or tribes, will retain the jaw and teeth of the spade-toothed whale, which are sacred in Māori culture, according to the AP. The rest of the skeleton, featuring 3D-printed replacements for those parts, will wind up in the Tūhura Otago Museum in Dunedin, where the public can revel in the presence of one of the world’s rarest mammals.

“It’s a week I’ll never forget in my life,” van Helden says in the statement, describing the dissection. “It’s certainly a highlight, and it’s the start of the storytelling around this beautiful animal.”

Eli Wizevich | | READ MORE

Eli Wizevich is a history correspondent for Smithsonian. He studied history at the University of Chicago and previously wrote for the El Paso Times.