The recent announcement of a private company's de-extinction of the ‘Dire wolf’ created excitement and controversy in the scientific world. In a world increasingly dominated by human activity, the news of species disappearing and being brought back often overshadows the incredible stories of life that persist, sometimes against all odds. One of the more encouraging news stories recently is the remarkable rediscovery of a creature so elusive that it was considered extinct for over a century. Typhloperipatus williamsoni, a unique species of velvet worm, has resurfaced from the Eastern Himalayas more than a century after it was last seen.
Velvet worms, scientifically known as Onychophora, are a bizarre mix of a worm, a caterpillar, and a slug, covered in velvety skin. These creatures are often called ‘living fossils’ because their body plan has remained essentially unchanged for hundreds of millions of years, predating even the dinosaurs. They are ancient lineages that offer a glimpse into the history of life on Earth.
Typhloperipatus williamsoni is a member of this group, first described way back in 1913 from specimens collected during a British expedition in the then remote and unexplored Siang Valley in Arunachal Pradesh. For over a century, this species remained only as a few preserved specimens in museum drawers and mentions in old scientific papers on the biodiversity of the Himalayas. No one had observed another Typhloperipatus williamsoni in the wild since its initial discovery, and its place in the evolutionary tree of velvet worms remained a mystery.
Between 2021 and 2023, a team of scientists from Ashoka Trust for Research in Ecology and the Environment (ATREE) ventured back into Siang Valley, following century-old clues in a dense, mountainous landscape, to find the long-lost Typhloperipatus williamsoni. Their persistence paid off when they found not one, but two individuals of this incredibly rare species. One was found near the original location described over a hundred years ago, and the other in a nearby, previously unexplored area.
To understand this rediscovered species, the scientists used a combination of observations and genetic analyses. First, they carefully examined the worms' physical characteristics, comparing them to the original description from 1913 to confirm their identity. They also collected tissue samples to map the worm's genetic code. They focused on mitochondrial DNA, a specific part of the genetic material passed down through the maternal line, which acts like a molecular time capsule for tracing evolutionary relationships.
By sequencing specific genes from this DNA, they were able to place Typhloperipatus williamsoni on the velvet worm family tree, a process called phylogenetic analysis. This method allowed researchers to use DNA sequences to see how Typhloperipatus is related to other velvet worm species. Their analysis revealed that Typhloperipatus williamsoni is most closely related to velvet worms found in Southeast Asia, specifically a group called Eoperipatus.
The discovery finally solves the century-old mystery of where this unique Indian species fits in the velvet worm evolutionary tree. Previously, Typhloperipatus was the only major group of velvet worms for which genetic data were missing, leaving a significant gap in our understanding of their evolutionary history. This new research plugs that gap, painting a more complete picture of how these ancient creatures diversified across the globe.
While this rediscovery and genetic analysis are groundbreaking, the researchers acknowledge some limitations. Their study is based on mitochondrial DNA, which provides valuable insights but represents only a fraction of the total genetic information. Future studies using a broader range of genetic data, including nuclear DNA, could further refine our understanding of Typhloperipatus's evolutionary journey and its precise relationships with other velvet worm groups.
The rediscovery of Typhloperipatus williamsoni is a potent reminder of the hidden biodiversity that still awaits discovery, especially in biodiversity hotspots like the Himalayas. It underscores the importance of continued exploration and biodiversity surveys, particularly in regions facing increasing environmental pressures. Sadly, the researchers also noted that the habitat of Typhloperipatus is under threat from deforestation, agriculture, and unsustainable farming practices. This rediscovery is therefore not just a scientific triumph, but also a call to action. It highlights the urgent need for conservation efforts to protect this unique and ancient lineage, ensuring that this species doesn't vanish again.