(CNN)In 2019, American and Vietnamese scientists were researching biodiversity in the jungles and mountains of Vietnam when they stumbled upon a strange-looking snake.
It was dark and iridescent, its scales shifting through blues and greens in the light. The scales were small, ridged, and oddly patterned. The seasoned scientists had no idea what it was -- and soon realized they were looking at an undiscovered species.
"That was a really exciting moment," said Aryeh Miller, one of the researchers and a fellow at the Smithsonian's National Museum of Natural History, on the Smithsonian's blog. "The specimen looks very different. So different, in fact, that we didn't know immediately what it was."
The researchers, from the Smithsonian and the Vietnam Academy of Science and Technology, published their findings in the journal Copeia on Monday.
They spotted the snake in Vietnam's northern Ha Giang province, which borders China. There were a few physical clues in the mystery snake's appearance: notably, it didn't have bright-light photoreceptors in its eyes, suggesting it burrows underground or beneath leaves. These types of snakes are particularly hard to find due to their life beneath the surface.
They also soon realized it was a species belonging to the rare genus Achalinus, also known as "odd-scale