Rare 4.5-million-year-old freshwater fish fossils found in Dehradun’s Shivalik foothills, a region previously known only for land animals

In a significant scientific breakthrough, researchers have discovered the first-ever fossils of aquatic life in the Shivalik foothills near Mohand on the outskirts of Dehradun — a region long known only for terrestrial animal remains, according to a report by Times of India.

This unexpected find is expected to reshape scientists’ understanding of the prehistoric environment of the area during the Pliocene epoch, which spanned from 5 to 2.5 million years ago.

The discovery was made by a team led by scientists from the Dehradun-based Wadia Institute of Himalayan Geology (WIHG), along with researchers from multiple institutions including Doon University, Panjab University, and international collaborators from Taiwan.

Key findings from the fossils

The fossils consist of tiny ear bones, known as otoliths, belonging to three distinct freshwater fish species — snakehead (Channa sp.), goby (Gobiidae indet.), and gourami (Trichogaster fasciata).

Senior scientist Ningthoujam Premjit Singh of WIHG told TOI that the discovery of the gourami fish fossil marks its first recorded appearance in India and only the second in the world, after a previous find in Sumatra, Indonesia.

According to Singh, these fossils are estimated to be around 4.5 million years old.

What the discovery reveals

The presence of these fish species indicates that during the Pliocene epoch, the Shivalik region had calm, stable freshwater bodies surrounded by dense vegetation. The gourami, which prefers quiet waters for spawning, and the ambush-hunting snakehead fish suggest a peaceful aquatic ecosystem quite different from the terrestrial-dominated picture scientists previously had of the area.

The peer-reviewed research study, published by Springer-Nature in its Palaeobiodiversity and Paleoenvironments journal on March 31, noted that this otolith assemblage represents the first Pliocene otolith record from the region and provides a valuable window into the past freshwater ichthyofauna of northern India.

"This tells us a lot about similar climatic and ecological conditions of the landscapes," Singh told TOI.

How the fossils were collected

Researchers collected approximately 500 kg of bulk sediments from fossil localities during the 2024 field season. These samples were carefully processed in the WIHG laboratory to extract the delicate otoliths.

The multi-institutional study concluded that these newly discovered Pliocene otoliths offer direct evidence of freshwater fishes in the ecosystems of northern India, giving scientists a more comprehensive view of the region’s ancient biodiversity. The team has called for further fossil discoveries and expanded sampling to better understand the ancient freshwater ecosystems.

(With TOI inputs)