Scientists just found a new walking shark in a tiny corner of Papua New Guinea, and the meter-long species may be vulnerable because its range is so restricted

Dr. Christine Dudgeon from the University of the Sunshine Coast was conducting a night survey off the coast of Papua New Guinea (PNG) when she caught a small, nocturnal shark by hand and guided it back to the research vessel. Her PhD student, Jess Blakeway, saw the creature in the boat's lights and instantly knew something was wrong. The color pattern was completely new: dashes of white on a brown body, not at all the leopard-spotted species they were expecting to meet. “New species of sharks don’t come along that often, and it's most definitely the first one named after me,” Dudgeon said.

In a peer-reviewed paper in the Journal of the Ocean Science Foundation, Blakeway, Dudgeon and colleagues, including Professor Kathy Townsend, Dr Mark Erdmann of Re: wild and the California Academy of Sciences, and Dr Gerald Allen of the Western Australian Museum, reported that what they’d caught was a species entirely unknown to science. It’s now officially called Hemiscyllium dudgeonae, Dudgeon’s Walking Shark in honor of the researcher who has studied the genus for over 20 years.

Yes, this shark really walks
"Walking shark" sounds scary, but it isn't, really. These small bottom-dwelling sharks, also known as epaulette sharks, use all four fins like limbs to crawl across shallow reef flats at low tide. They are nocturnal, grow to about a meter in length, feed on invertebrates from the seafloor and are not dangerous to humans.

What makes them really interesting to scientists is how recently this ability evolved. According to Dudgeon et al.' s 2020 study in Marine & Freshwater Research, these sharks likely developed the ability to walk only about 9 million years ago, an incredibly fast rate of evolution. According to the same study, for context, hammerhead sharks evolved some 45 million years ago. Experts say the ability to walk is an evolutionary advantage for these sharks, allowing them to hunt in tidal pools that other predators simply cannot reach.

How the discovery unfolded
The research team was in Milne Bay and nearby shallow waters to study the distribution of endangered epaulette sharks already known to science, according to the Journal of the Ocean Science Foundation paper. More than 70 dedicated surveys were conducted at 35 sites across 15 localities, using diving, snorkeling and reef walking to catch sharks by hand.

After placing the unusual specimen in a tub of fresh seawater to take measurements, blood samples and tissue samples, the team spent the next two nights locating 11 more individuals with the exact same patterning. It was only after genetic analysis back in Australia that scientists could formally confirm it as a new species, the first described in the Hemiscyllium genus since 2013. The research also updated the known geographic ranges of two other epaulette shark species off the island of New Guinea, casting doubt on a long-held belief that each walking shark species occupied completely separate, non-overlapping ranges separated by rivers or deep water, according to the same research.

In the Milne Bay region, the new species goes by the local name of kadedekedewa, which roughly means “dog shark” or “lazy shark,” a reference to its slow, four-limbed shuffle across the reef.

Why this discovery is also a warning sign
The study, published in the Journal of the Ocean Science Foundation, says H. dudgeonae occurs in an extremely limited area, a small pocket of shallow coastal waters off southeastern PNG, making it immediately vulnerable to habitat degradation, local fishing activity, and climate change. Five species in the walking shark genus are already listed as threatened with extinction on the IUCN Red List under criteria specifically related to restricted geographic range, which apply to only 3% of all sharks worldwide. The research team plans to return in October to gather sufficient data for a formal IUCN assessment to determine whether H. dudgeonae should be listed as Vulnerable or Endangered.

This makes the overall outlook for sharks even more urgent. According to Sherman et al.' s 2023 study in Nature Communications, nearly 59% of the 134 coral reef-associated shark and ray species are now threatened with extinction. The same study concluded that overfishing is the main culprit, aggravated by climate change and habitat destruction; the same trio of threats now threatens the newly discovered walking shark.

We're still discovering what we're losing
There is something quietly sobering in all this. Scientists have just discovered a species that probably lived for millions of years in a tiny corner of the Pacific, and already they fear it may vanish. For most Americans, sharks conjure up images of great whites or tiger sharks cruising the open ocean. But it’s the small, unnoticed ones like H. dudgeonae quietly waddling across a reef flat in Papua New Guinea at 2 am that may be most at risk, and most in need of attention.