A new species of pit viper has been discovered in southern Tibet, according to a study published September 12 in the journal Animals. The discovery was made by a team of researchers conducting fieldwork in the Himalayan foothills as part of an effort to document reptiles and amphibians in the region.
The Himalayas are known as a “global biodiversity hotspot,” but many areas remain under-surveyed due to their remote location, rugged terrain, and frequent geological instability, according to the study. During their June expedition, scientists encountered several unfamiliar snakes near riverbanks surrounded by dense vegetation. They collected three specimens for closer examination.
Analysis revealed that these snakes belonged to a previously unidentified species, now named Trimeresurus pretiosus, or the Yadong green pit viper. The researchers described the new species as “relatively small,” with individuals reaching about 25 inches in length. The snakes have triangular heads and relatively long tails.
Photos from the study highlight the snake’s “bright grass‑green” coloration, which allows it to blend into its surroundings. Male vipers have reddish-brown eyes and a red and white stripe along their sides, while females display orange-yellow eyes and only a white stripe.
The Yadong green pit viper inhabits forests at elevations around 6,000 feet. The animals were found either within grassy vegetation or near rocks close to riverbanks. Two photos included in the study show how well these snakes camouflage themselves among lush vegetation.
One female specimen regurgitated a partially digested mouse after being captured, suggesting that the species may primarily feed on small mammals such as rodents. Pit vipers are generally venomous and can be medically significant; however, detailed information on the toxicity of this new species is not yet available.
The name Trimeresurus pretiosus comes from Latin for “precious” or “valuable.” According to researchers: “striking and vivid colouration… makes it resemble a hidden green gem within the pristine forest.” The common name refers to Yadong County, where all identified specimens were found so far. This area is located in southern Tibet—a territory controlled by China that borders India and Bhutan.
Although herpetologists have surveyed Yadong County since the 1970s, this marks the first recorded discovery of a pit viper there, indicating that Trimeresurus pretiosus is extremely rare in the wild. Researchers noted: “It is plausible that the new species also occurs in suitable habitats” nearby, but further fieldwork will be needed to confirm this possibility.
Because of its rarity and limited distribution—and ongoing human pressures—researchers suggest that the Yadong green pit viper should be considered vulnerable until more data can be gathered. Identification was based on physical characteristics such as size, body proportions, eye color, scale patterns, genitalia structure and confirmed through DNA analysis showing at least five percent genetic divergence from related species.
The research team included Yuhao Xu, Tan Van Nguyen, Zhenqi Wang, Tierui Zhang, Nikolay Poyarkov, Cong Wei, Gernot Vogel, Jianchuan Li, Jundong Deng, Fanyue Sun, Lifang Peng and Shiyang Weng.
