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New fossils reveal ancient carnivorous mammals in Himalayan foothills

A group of researchers, including Harrisburg University of Science and Technology (HU) Professor Dr. Steven Jasinski, has published a study on fossil carnivoran mammals from the foothills of the Himalayan Mountains in northern India.

Dr. Jasinski, of HU's Department of Environmental Science & Sustainability, and researchers from the Paleo Research Society and Paleo Museum, the University of Sialkot, and the University of the Punjab, described new fossil specimens of carnivoran mammals that lived in northern India from about 10 million to 4 million years ago.

According to the new published in the Journal of Mammalian Evolution, these new fossil specimens add important new information to our collective knowledge of carnivorous mammals.

The Siwaliks, also called the Siwalik Group, is a mountainous region and part of the outer Himalayas. The Siwaliks stretch through Pakistan, India, Nepal, and Bhutan. The fossil animals of the Siwaliks lived in the shadow of the Himalayan Mountains from around 18 million years ago to about 1 million years ago.

These fossil deposits are known to have a diverse mammalian fauna, with many species of artiodactyls (bovids, suids, hippopotamuses, giraffoids), perissodactyls (rhinoceroses, horses, chalicotheres), proboscideans (elephants and their relatives), rodents, primates, and carnivorans.

Carnivorans, including carnivorous mammals like martens, wolverines, civets, and cats, were the focus of the new study. In particular, Dr. Jasinski and his co-authors focused on fossils collected from the Haritalyangar region in northern India.

The newly collected fossils include mustelids, viverrids, and felids (cats). Mustelids include animals like ferrets and weasels and are found on every continent today except Australia and Antarctica. Viverrids are small or medium-sized carnivorans, like civets and genets, that currently live in Africa, southern Asia, and southern Europe.

The fossil material identified includes a partial fossil skull, along with fossil jaws and teeth. Among these fossils, the researchers identified the first upper-jaw material of a rare mustelid named Martes lydekkeri and rare material of a small fossil feline, in addition to two new species of fossil mammals: a mustelid and a viverrid.

The new species of mustelid, Circamustela bhapralensis, is the first report of this fossil mustelid on the Indian subcontinent. It is also the youngest member of the genus, with older species known from Europe. It suggests its members migrated from Europe just over 5 million years ago, finding their way to the outer Himalayas while evolving smaller body sizes as they did. The new species would have been about the size of a ferret, weighing around 1 to 2 kg.

The new species of viverrid, Vishnuictis plectilodous, is a younger species with complex teeth. The teeth suggest a varied diet compared to the more carnivorous diet of its close relatives. Additionally, the new species is one of the largest, if not the largest, viverrids known. It could have grown to around the size of a leopard and weighed over 100 kg.

"These new fossils are really giving us a better idea of what the ecosystems at the base of the Himalayas would have been like around 5 million years ago," said Dr. Jasinski. "Our research is helping us not only understand the biodiversity of our world but also providing crucial information for how our world has changed.

"This is vital to our understanding of how our world will continue to change due to the shifting, potentially volatile, conditions we are currently dealing with. Our study of the past is essential to being able to make predictions about our world's future."

These fossils come from a time of pronounced changes for this region; global temperatures were generally cooling throughout this time, and mammalian carnivores were dealing with these changing conditions just as other animals and plants were.

"With the addition of fossil species previously known only from Europe and two new species of carnivorans, the mammals of the region and their taxonomy are more complex than we previously understood," added Dr. Sayyed Ghyour Abbas, of the University of Sialkot.

"This hints at the presence of direct connections, potentially through migration of smaller mammals, between Europe and Asia during the Late Miocene (around 10 to 5 million years ago). These ancient food webs and ecosystems are also more complex than we realized … the study of these interactions will provide new insights that will help us understand … how changes, including climate change, may have affected them, thereby helping inform ongoing conservation efforts."

The research team hopes more collecting, more fossils, and more research will provide an even clearer picture of this key time in the past. The fossil record, as the basis for understanding life on Earth from the first 4.5 billion years of its history, is key to predictions moving forward. "If we can use what we know about the past to predict aspects of our future," says Dr. Jasinski, "we can work to counteract some of those potential aspects of our future, and maybe even use that data to help protect our ecosystems for future generations."

Jasinski has been a member of other teams researching fossils and evolution—including another paper on fossil carnivores from southern Asia—and has contributed to the naming of several new species of dinosaurs and turtles. These include the ceratopsid dinosaur Menefeeceratops sealeyi, the ceratopsid dinosaur Sierraceratops turneri, the ceratopsid dinosaur Bisticeratops froeseorum, the tyrannosaurid dinosaur Tyrannosaurus mcraeensis, the fossil softshell turtle Hutchemys walkerorum, and the fossil pond turtle Chrysemys corniculata.