The Siwaliks: Fossil Heaven On Earth

We drive through the dusty road that promises to take us to my much-awaited destination ensconced in the Siwalik Hills in Himachal Pradesh. The hills grow bigger as we get closer, and soon we are in Suketi village, driving past the exposed rocks on the side of a hill made up of alluvium layers.

I think to myself what it would be like to find a bone of a prehistoric animal sticking out of those white rocks which I know to be rich in vertebrate fossils. I fancy myself as this century’s Mary Anning, a pioneering fossil collector and palaeontologist from 19^th century England, a pick axe in hand digging for fossils…

Fiberglass life-size models of Megalochelys atlas, an extinct giant turtle, which once lived in the Siwalik Hill ranges. © vjdchauhan/Wikimedia commons

The extinct sabre-toothed tigers as big as the modern tigers, flaunting their long, sharp upper canine teeth are unmissable. These giant cats must have been formidable predators of the grassy plains and low hills of the Siwaliks over 2.5 million years ago.

honk-honk…when a loud honk of the car snaps me out of my reverie!

We are close and I am giddy with excitement as my long-time wish of visiting the Siwalik Fossil Park is finally materialising. The physical tiredness from spending the last 24+ hours in the train travelling from Mumbai to Chandigarh slowly withers away, much like the sediments that wear off exposing a fossil ripe for discovery. The fossils that have survived for millions of years are going nowhere, but I am in a rush.

A blue-green museum building, property of the Geological Survey of India (GSI), slowly comes into view, its austerity belying the rich geological and palaeontological collection that it houses. The museum is located inside the Siwalik Fossil Park, a geological heritage site situated in the Himalayan region of India. Top half of the giant, prehistoric and extinct elephant species Stegodon ganesa flaunting its magnificently long (4-5 metres) pair of tusks is clearly visible across the museum’s boundary wall. As we enter through museum gates, some more life-sized fiberglass models of bygone animals which thrived in the Siwalik region about 1-2.5 million years ago until the advent of the Ice Age, greet us.

A fiberglass model of the extinct elephant species Stegodon ganesa visible in the premises of the Siwalik museum building. ©Purva Variyar

There are the extinct ancestors of the modern giraffe called the four-horned giraffes (Sivatherium giganteum) which stood two meters high at the shoulders, with their massive horns and comparatively stockier necks. The extinct sabre-toothed tigers as big as the modern tigers, flaunting their long, sharp upper canine teeth are unmissable. These giant cats must have been formidable predators of the grassy plains and low hills of the Siwaliks over 2.5 million years ago. I think of how different the Siwaliks must have looked all that while ago teeming with a mesmerising diversity of giant mammals.

In that fleeting moment you feel a grand connection to the Earth’s rich past, and all the creatures that came before you.

The extinct ancestors of the modern giraffe called the four-horned giraffes (Sivatherium giganteum) which stood two meters high at the shoulders. ©Purva Variyar

Many of the fossils of the aforementioned prehistoric mammals and other vertebrates have been recovered from right here, within the Siwalik Fossil Park. I am standing at the site of so many incredible fossil discoveries and scientific breakthroughs. The Siwalik Group of rocks in Sirmur District is literally bursting at its seams with fossils of mega mammals of the past. A tooth of the extinct hippopotamus (Hexaprotodon sivalensis) here, a hip bone of a long-lost rhino or an elephant there…. Locals often stumble upon fossilised tusks of prehistoric elephants along the river beds and banks of the Markanda river that flows through Sirmur!

A Menagerie of Fossils Big, Bigger, and Small

We step inside the museum, where a large room with rows of precious vertebrate fossils are meticulously laid out in their protective glass chambers beckoning me. At first glance, the fossils don’t make much sense to me quite that easily. In that moment I wished I had been trained in palaeontological sciences. Your eyes have to adjust, and you have to soak in the information on the labels to comprehend what you’re looking at. But once the realisation dawns on you, suddenly the fossils are drenched in beauty, meaning, and significance! As our museum guide, a local resident of a nearby town, begins to describe the various specimens one by one, his fluency of the subject and Hindi language has us hanging on to his every word.

That’s the thing about fossils. They stoke your imagination unlike anything else. A fossil is simply a rock until the cloud of ignorance is lifted and details become clearer, and then suddenly the amorphous rock is a fascinating remnant of an extinct prehistoric creature. In that fleeting moment you feel a grand connection to the Earth’s rich past, and all the creatures that came before you.

The fossils of various extinct elephant species from the Siwalik region on display at the Siwalik museum (top); and a partial skull with the molar teeth structure of elephant species Stegodon insignis (bottom) clearly visible. ©Purva Variyar

The guide leads us to a table on which fossils of extinct elephants are purposefully arranged alongside intriguing installations depicting the fascinating evolution of elephants! Partial fossilised jaw skulls, about 1.5 to 3.3 million years old, with rows of large grinding molar teeth, belonging to the extinct elephant Stegodon insignis, which along with the other elephants of the Stegodon genus that evolved here in the Siwaliks, are particularly interesting. Each one of those large molar teeth in an adult elephant would have weighed up to four kilogrammes, the guide tells me, and worked like a conveyor belt with old worn off teeth making way for the unused teeth waiting at the back of the jaw.

He goes on to show us some more marvellous fossil specimens, such as the near complete, patched skull with formidable mandibles of the extinct hippo Hexaprotodon sivalensis which once roamed the Siwaliks with other megaherbivores. Then there are the fossils of carnivores such as the giant, prehistoric otter Enhydriodon sivalensis possibly the largest mustelid at the time in the Siwalik Hills; and a canine tooth that belonged to an extinct cat species; among others.

Fossilised skull and mandible (left) and teeth and jaw fragments (right) of the extinct species of hippopotamus Hexaprotodon sivalensis from 2.5 to 3.3. million years ago. ©Purva Variyar

“Up until a few years ago, visitors to the Siwalik Fossil Park would be taken on a tour of the park to the very spots where many of these fossils were recovered from. The fiberglass models were installed at those very locations across the park. But, as the funds dwindled, we had to scale down the park displays and activities,” the guide explains. I can’t help feeling dejected at hearing this. But I am not surprised. I think about the complete lack of visitors at the museum at that moment, except for my friends and I. There is sadly, very little interest in fossils and rocks in India. Especially with respect to India’s own fossil wealth.

“In India, anything geological is rather niche in terms of value, awareness and protection protocol. The Geological Survey of India is however trying its level best to declare such fossil treasure troves as geoheritage sites and include them in the UNESCO Geopark list,” states Dr. Sunayana Sarkar, Geologist and Professor of Earth Sciences. “So there is hope ahead. The powers that be ought to invest in the Indian geodiversity and come up with meticulously preserved and curated natural history museums with dedicated fossil and mineral sections. In India, we have enough paleontological treasure to construct one in every town perhaps!”

A life-sized fiberglass model of a extinct gharial species (Gavialis sp.) displayed at the Siwalik museum. ©Purva Variyar

Mammalian fossils aren’t the only stars at the Siwalik museum. Fascinating fossils of prehistoric reptiles and fish too make their presence felt here! Fossil carapaces of turtles, vertebrae and scales of ancient fish, skulls and teeth of crocodilians, and so much more adorn the collection. One very interesting crocodilian fossil is the highlight of the reptilian fossil menagerie. It is that of an extinct species of a type of crocodilian called gharial. The guide points at a rock and asks me to look at it closely. Slowly the characteristic shape of the gharial’s snout and rest of its skull become discernible. It is a fossil of an extinct gharial that belonged to the genus Gavialis. Its close living relative is the critically endangered gharial Gavialis gangeticus which is on the brink of extinction. The significance of it is not lost on me.

Palaeontological Significance of the Fossil-rich Siwalik Hills

The history of palaeontological explorations in the Siwaliks in the Himalayan foothills can be traced back to the 19^th century when British officers of the East India Company unearthed a wealth of fossils. Many of these important fossils, from the Plio-Pleistocene epoch (5.3 million to 11,700 years ago) excavated from the Siwalik Hills found their way to British and Indian museums and private collections. Major fossils continue to be discovered and described from the region even today. In recent times, fossils of elephant species, reptiles, and even apes have been discovered from the Siwalik Hills.

Approximately one metre long fossil tusk of a giant extinct elephant relative Anancus sivalensis from the Siwalik region on display at the museum. In the background you can see a picture of the stamp depicting Stegodon ganesa that was issued by the Geological Survey of India in 1951. ©Purva Variyar

“The Himalayas and its orogeny (process involving folding of Earth’s crust to form mountains) are fascinating to say the least. Add to it the fantastic journey of the landmasses because of plate tectonic movements and the evolutionary tangents that the species have achieved thereby. The Shivalik fossils represent both the contiguity of evolutionary trends as well as fragmentations, before, during, and after the Gondwana assembly. They serve as the glue to the unconsolidated parts of geological history that once existed as a whole before the Himalayas were formed and are therefore irreplaceable and precious to the global Earth Science research cohort. They must be protected at all costs,” says Dr. Sarkar.

The Siwalik fossils give us a glimpse into the evolutionary history of mammals and so many other vertebrates, including humans, helping to fill the important gaps in their evolutionary stories. These fossils are shining jewels in the rich repository of India’s fossil and geological wealth. A fossil paradise.

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About the author:

Purva Variyar is a wildlife conservationist, science writer and editor, and heads WCT’s Communications vertical. She has previously worked with the Sanctuary Nature Foundation, and The Gerry Martin Project.

Disclaimer: The author is associated with Wildlife Conservation Trust. The views and opinions expressed in the article are her own and do not necessarily reflect the views and opinions of Wildlife Conservation Trust.

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