A new species discovered in Germany

The dispersal of Vishnouonyx otters from the Indian subcontinent to Africa and Europe around 13 million years ago. The star (HAM 4) indicates the position of the Hammerschmiede fossil site. Credit: Nikos Kargopoulos

An Indian otter found in Hammerschmiede: NeptuneVishnu’s otter arrived 11.4 million years ago from Southeast Asia.

Researchers at the universities of Tübingen and Zaragoza have discovered a previously unknown species of otter in strata 11.4 million years old at the Hammerschmiede fossil site.

The excavation site in the Allgäu region of Germany became world famous in 2019 for the findings of the bipedal monkey Danuvius guggenmosi. The new species, published today in the Journal of Vertebrate Paleontology, had been named Vishnuonyx neptuni, which means Neptune’s otter Vishnu. The genus of otter Vishnu was previously known only in Asia and Africa.

The research team is carrying out excavations in Hammerschmiede under the direction of Professor Madelaine Böhme of the Senckenberg Center for Human Evolution and Palaeoenvironment at the University of Tübingen. He has already recovered more than 130 different species of extinct vertebrates from river deposits attributed to ancient Guenz. Many of these species are adapted to life in and around water. However, the detection of a Vishnu otter in Bavaria was unexpected, since representatives of this genus were previously known only in regions outside of Europe.

Scattering of Vishnu’s otters

One in six species of predatory mammals today lives in aquatic environments, either in the oceans, such as seals, or in freshwater, such as otters. The evolutionary history of the 13 species of otters that exist today is still relatively unexplored. Vishnu’s otters (Vishnuonyx) are medium-sized predators weighing between 10 and 15 kilograms that were first discovered in the sediments of the Himalayan foothills. They lived 14 to 12.5 million years ago in the major rivers of South Asia.

Vishnuonyx neptuni Lower jaw

The lower jaw of the new species of otter, Vishnuonyx neptuni, with a detailed view of its teeth in a 3D model taken with a micro-scanner. Credit: Nikos Kargopoulos

Recent discoveries have shown that Vishnu’s otters reached East Africa around 12 million years ago. The discovery in the 11.4-million-year-old Hammerschmiede strata is the first evidence that they also occurred in Europe – possibly spreading from India throughout the Old World. Like all otters, Vishnu’s otter depends on water; it cannot travel long distances by land. Its enormous dispersion of more than 6,000 kilometers across three continents was made possible by the geographical location 12 million years ago: newly formed mountain ranges from the Alps in the west to the Iranian Elbrus mountains in the east separated a large ocean basin of the Tethys Ocean. , the precursor of the Mediterranean and the Indian Ocean.

This created the Paratethys, a vast body of Eurasian water that stretched from Vienna to beyond what is now the Aral Sea in Kazakhstan. Twelve million years ago, it only had a close connection with the Indian Ocean, the so-called Araks Strait in the region of modern Armenia. Researchers speculate that Neptune’s otter Vishnu followed this westward connection and reached southern Germany, ancient Guenz, and the Hammerschmiede via the emerging delta of the ancient Danube west of this which is now the city of Vienna.

Predatory fish teeth

At the recently founded Center for Visualization, Digitization and Replication of the Department of Geosciences at the University of Tübingen, researchers used computed tomography methods to visualize the smallest details of the tooth structure of fossils. This technique allowed the precise observation of very small structures in the otter’s dentition. The sharp cusps, sharp blades, and restricted grinding areas suggest a predominantly fish-based diet. Ecologically, the Vishnu otter of Neptune therefore resembles the Eurasian otter more than the Pacific sea otter or clawless otters from Africa and Asia – both groups prefer crustaceans or shellfish with fish in their diet.

Reference: “New species from the Upper Miocene Vishnuonyx (Carnivora, Lutrinae) from the hominid locality of Hammerschmiede, Bavaria, Germany “by Nikolaos Kargopoulos, Alberto Valenciano, Panagiotis Kampouridis, Thomas Lechner and Madelaine Böhme, September 16, 2021, Journal of Vertebrate Paleontology.
DOI: 10.1080 / 02724634.2021.1948858

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