The high mountain ranges of Asia remain among the least biologically explored regions of the continent. Now, an international team of researchers has shown that one of their most elusive venomous snakes, long treated a single species, is in fact a complex of five distinct species, three of which are new to science.

Published in the open-access journal ZooKeys, the study revises the Himalayan pit viper group using a combination of fresh and historical DNA, morphology, skeletal anatomy, and ecological observations. The data reveals that what scientists had long treated as a single widespread species, the Himalayan pit viper first described in 1864, actually consists of multiple deeply distinct evolutionary lineages.

The analyses identified five clearly distinct species-level lineages, i.e. the Himalayan pit viper in the strict sense, Gloydius chambensis described in 2022, and three previously unrecognised species from different parts of Pakistan and Nepal. Alongside genetic divergence, these lineages exhibit distinct morphological and skeletal variations.

“These mountain systems still harbour overlooked vertebrate diversity and hold important clues to the biogeography of Asia,” says Daniel Jablonski of Comenius University Bratislava, who has been conducting extensive research in Pakistan and Afghanistan for many years. “By combining modern field sampling with data from historical museum specimens, we uncovered evolutionary lineages that had remained hidden for more than a century after the original description of the Himalayan pit viper.”

A key element of the discovery was the integration of newly collected material with a powerful source of evidence: DNA extracted from museum specimens collected in the 19th and early 20th centuries. This included the original type specimen of the Himalayan pit viper, allowing the researchers to clarify the identity of the species in its strict scientific sense.

The study underscores the enduring scientific value of natural history collections. Indeed, specimens gathered by earlier generations of explorers and preserved in museums are still helping scientists solve modern biological puzzles, especially in regions where fieldwork remains difficult.

In fact, part of the discovery had been waiting in plain sight. “Museum specimens are not just records of the past. They are active research tools and essential infrastructure for future science,” says Sylvia Hofmann from the Museum Koenig as part of the Leibniz Institute for the Analysis of Biodiversity Change, who has comprehensively worked in the Himalaya and Tibetan Plateau during the past 20 years.

“Some of the key evidence had been sitting in museum collections for more than a hundred years. We just didn’t have the tools to recognize it. As analytical methods continue to improve, the scientific value of these collections will only grow and revealing biodiversity we didn’t even know was there.”

Representatives of the herpetofauna play an important role in the ecosystem, particularly as ecological indicators, within the food chain, and as predators in pest control. A group of top predators in the region consist of pit vipers adapted to mountainous environments, which have so far been studied only very inadequately in the Himalayan region.

“Our work aims to close these gaps in knowledge and to lay the groundwork and provide inspiration for further, in-depth studies on this ecologically and medically relevant group,” says Frank Tillack of the Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Research, who maintains close ties with Nepalese colleagues and has been collaborating with them for 35 years on projects concerning the biodiversity of herpetofauna in the Himalaya.

The study also emphasises how much remains to be discovered in regions that have long been difficult to access for scientific research. “Pakistan’s high mountains are still full of biological surprises,” says Rafaqat Masroor of the Pakistan Museum of Natural History, the country’s leading herpetologists. “This finding highlights how little we still know about a region long shaped by socio-political instability.”

Beyond taxonomy, the findings also carry an important conservation message. “Each of the newly recognised species seems to occupy a relatively restricted range in fragile mountain environments, highlighting new ecological and evolutionary questions,” concludes Daniel Jablonski. Without recognising such diversity, it would be impossible to assess it accurately or protect it effectively.

Jablonski D, Tillack F, Mahlow-Tillack K, Petzold A, Wilzo M, Das A, Idrees M, Baniya CB, Masroor R, Hofmann S (2026) Integrative taxonomy reveals previously undescribed diversity within the Gloydius himalayanus complex (Squamata, Viperidae, Crotalinae) from the Himalaya and Hindu Kush. ZooKeys 1280: 83-153. https://doi.org/10.3897/zookeys.1280.182768