Hippos are now seen only in sub-Saharan Africa, but new research reveals that these giant, water-loving animals lived in central Europe much more recently than scientists once believed.
A team of international researchers has found that hippos survived in what is now southwestern Germany well into the last ice age—tens of thousands of years later than previously assumed.
The study, published in Current Biology, was led by researchers from the University of Potsdam and the Reiss-Engelhorn-Museen Mannheim, in collaboration with ETH Zurich and other international partners.
It shows that common hippos (Hippopotamus amphibius) inhabited the Upper Rhine Graben between about 47,000 and 31,000 years ago—a period that was part of the last ice age.
Until now, scientists thought these animals had disappeared from Europe around 115,000 years ago, at the end of the last warm period known as the interglacial.
The discovery was made by analyzing exceptionally well-preserved bones found in gravel and sand deposits in the Upper Rhine Graben, a region known as an important record of Europe’s past climates.
“It’s amazing how well the bones have been preserved,” said Dr. Ronny Friedrich, an expert in dating ancient materials at the Curt-Engelhorn-Zentrum Archäometrie in Mannheim.
“At many skeletal remains, it was possible to take samples suitable for analysis—that is not a given after such a long time.”
The research team used a combination of ancient DNA sequencing and radiocarbon dating to determine the age and origin of the fossils.
Genetic analysis revealed that these Ice Age hippos were closely related to modern African hippos and belonged to the same species.
Radiocarbon dating confirmed that they lived during a relatively mild phase of the last ice age, when the climate in central Europe was temporarily warmer.
However, genome-wide analysis also revealed something intriguing: these European hippos had very low genetic diversity, suggesting that their population was small and isolated.
Despite being heat-loving animals, they coexisted with cold-adapted species such as mammoths and woolly rhinos, painting a picture of a surprisingly diverse Ice Age ecosystem.
“The results show that hippos did not disappear from central Europe at the end of the last interglacial, as we previously thought,” said Dr. Patrick Arnold, the study’s lead author.
“We now need to re-examine other European hippo fossils that may have been wrongly dated.”
Professor Wilfried Rosendahl, general director of the Reiss-Engelhorn-Museen Mannheim, added that the findings challenge long-held assumptions about Ice Age environments.
“The Ice Age was not the same everywhere,” he said. “These results remind us that local conditions created a complex and fascinating picture of life during that time.”
The discovery opens the door to fresh questions about how climate shifts shaped animal survival—and how Europe once hosted creatures we now associate only with Africa.
