A rare species of velvet worm, Typhloperipatus williamsoni, has been rediscovered in Arunachal Pradesh’s Siang Valley after remaining unseen for over 110 years. The species was last documented during the Abor Expedition in 1913.

Indian researchers confirmed its presence between 2021 and 2023 in the forest areas of Kallek and Yingku. The identification was established through morphological analysis and DNA comparison with century-old museum specimens.

Endemic to the Siang Valley, the rediscovery of T. williamsoni highlights the region’s rich and ancient biodiversity. Velvet worms, often referred to as “living fossils,” date back hundreds of millions of years and provide significant insights into early animal evolution.

This rediscovery marks a major step in understanding Arunachal Pradesh’s unique and largely unexplored biological heritage.