Hippos lived in Europe at the time of mammoths - sensational discovery

It was long believed that hippos disappeared from Europe about 115,000 years ago, when the warm climate of the last interglacial was replaced by the harsh cold of the Ice Age. However, a new study by German and Swiss scientists has disproved this belief.

DNA analysis of ancient remains showed that these giants lived in Central Europe much longer - up to 31 thousand years ago, that is, until the height of the ice age.

The work is published in the journal Current Biology and is based on radiocarbon analysis and ancient genetic material extracted from the remains of hippos found in the Upper Rhine region (Germany).

The researchers studied 19 fossilised hippopotamus remains from the rich palaeontological region of the Upper Rhine, where mammoth and woolly rhinoceros bones have also been found. One of the specimens preserved fragments of ancient DNA, allowing for the first time the genetic relationship of these animals to modern African hippos to be established.

Radiocarbon dating showed that the animals lived between 47,000 and 31,000 years ago - long after old estimates suggested that Europe's climate had become too cold for such heat-loving species.

"These findings completely change the view of the survival of large mammals in Europe during the last ice age," the study authors said.

The scientists suggest that hippos may have survived thanks to so-called interstadials - short-term warm phases between severe ice ages. During these times, some areas retained unfrozen bodies of water and enough vegetation to feed large herbivores.

However, genetic analyses showed low DNA diversity, indicating small isolated populations. Hippos probably did not live in Europe permanently, but returned periodically during favourable periods and left again when the climate became too cold.

Until now, all hippopotamus remains found in Central Europe were automatically attributed to the warm Aehemian interglacial, the period preceding the last glaciation. This was explained by the fact that hippos are traditionally considered "heat indicators" and, as scientists believed, could not exist in a glacial climate.

But new data from the Upper Rhine region has shown that the animals lived there during the Ice Age. Parallel dating of mammoth and woolly rhino bones from the same layers confirmed the accuracy of the measurements.

"Hippos turned out to be much more resilient than we thought. Their footprints in Europe are a reminder of how variable nature can be and how little we still know about the lives of ancient species," the authors say.