Carnivorous creature with ‘hook’-like teeth discovered as new species in Vietnam
On a rainy night in northern Vietnam, a carnivorous creature with “hook”-like teeth emerged from hiding and moved “slowly” along the bank of a mountain stream. Something about it caught the attention of nearby scientists — and for good reason.
It turned out to be a “secretive” new species.
A team of researchers visited the mountains of neighboring Nghe An Province and Thanh Hoa Province in 2019 and 2023, respectively, as part of a project to survey amphibian diversity, according to a study published Oct. 29 in the peer-reviewed journal Vertebrate Zoology.
During the first visit, researchers found a dead snake-like amphibian, known as a caecilian, the study said. They didn’t recognize it right away then, a few years later during their second visit, they found another similar-looking caecilian.
Intrigued by the unfamiliar-looking animals, researchers examined their anatomy and analyzed their DNA. The results showed that they’d discovered a new species: Ichthyophis griseivermis, or the Grey Worm caecilian.
Grey Worm caecilians have limbless, “worm-like” bodies reaching about 9.5 inches in length, the study said. Their heads have “blunt” snouts, “dark-blue” eyes and a “triangular” tongue. Their teeth are “notably recurved” and “almost hook-shaped.”
A photo shows the “uniformly grey-brown” new species. Its sides and stomach have “a slight pinkish-purple tint,” researchers said.
Researchers said they named the new species after the Latin words for “grey” and “worm” because of its coloring and after the character Grey Worm from the TV show “Game of Thrones” and book “A Song of Ice and Fire” by George R. R. Martin.
Generally, caecilians are “secretive” and “elusive” burrowing animals, living most of their lives underground, the study said.
One Grey Worm caecilian was found “slowly crawling among the stones on the banks of a small mountain stream” at an elevation of about 2,600 feet, researchers said. The other caecilian was found “as a dead, desiccated specimen on a sandy bank of a river.”
Like other caecilians, the Grey Worm caecilian is “carnivorous,” but “specific information about its diet” is unknown, the study said.
So far, the new species has only been found at two sites in northern Vietnam near the border with Laos but likely lives in other nearby areas. “Further field survey efforts are needed,” the study said.
The new species was identified by its DNA, coloring, body proportions, skeleton, snout shape, teeth, tail shape and other subtle physical features, the study said.
The research team included Nikolay Poyarkov, Dana Skorinova, Andrey Bragin, Veniamin Kolchanov, Vladislav Gorin, Alexey Trofimets, Alexander Yuzefovich, Dac Xuan Le, Tan Van Nguyen and Pavel Skutschas.
This story was originally published October 29, 2025 at 11:55 AM with the headline "Carnivorous creature with ‘hook’-like teeth discovered as new species in Vietnam."
