Small, isolated groups of the Common hippopotamus (Hippopotamus amphibius) were present in the upper reaches of the Rhine River in southwestern Germany during the Middle Ages. New research indicates their presence during the Weichselian period, which spanned from approximately 47,000 to 31,000 years ago.
Radiocarbon dating indicates that the common hippopotamus was present in the middle Weichselian (Hippopotamus amphibius) in the upper reaches of the Rhine River, Germany. Image credit: Gemini AI.
Hippos likely made their way into Europe from Africa through multiple waves, involving various species within the Hippopotamus genus, including the common hippo, which currently inhabits only sub-Saharan Africa.
At their peak distribution in Europe, hippos were found from the British Isles in the northwest to the Iberian and Italian peninsulas in the south.
Their fossil record generally suggests they thrived in temperate climates, characterized by denser vegetation and abundant freshwater bodies.
Nevertheless, their origins and relation to today’s African hippos, as well as the precise timing of their extinction in central Europe, remain ambiguous.
“Previously, it was thought that the common hippopotamus extirpated from central Europe around 115,000 years ago with the conclusion of the last interglacial period,” stated co-senior author Professor Wilfried Rosendahl, general director of the Ries-Engelhorn Mannheim Museum.
“Our findings reveal that hippos inhabited the Upper Rhine Valley in southwestern Germany from about 47,000 to 31,000 years ago.”
For this study, Professor Rosendahl and his team analyzed 19 hippo specimens collected from a fossil site located in the rift valley upstream of the Rhine River.
“The Upper Rhine Rift Valley serves as a significant continental climate archive,” noted study co-author Dr. Ronnie Friedrich, a researcher at the Kurt Engelhorn Zentrum Archaeological Institute.
“Animal bones preserved for millennia in gravel and sand deposits provide invaluable data for scientific inquiry.”
“It’s astonishing how well-preserved the bones are,” he added.
“In many human remains, we’ve successfully obtained samples suitable for analysis, but such conditions are not to be expected after such extended periods.”
By analyzing ancient DNA, researchers discovered that Ice Age hippos in Europe share a close relationship with modern African hippos, being part of the same species.
Radiocarbon dating confirmed their existence during the mid-Weichselian temperate climatic phase.
Furthermore, extensive genome-wide analyses indicated very low genetic diversity, suggesting a small, isolated population in the upper Rhine region.
These results, in conjunction with additional fossil evidence, imply that the heat-loving hippos coexisted with cold-adapted species such as mammoths and woolly rhinos.
“This finding indicates that hippos did not vanish from central Europe at the end of the last interglacial period, as was previously thought,” stated study lead author Dr. Patrick Arnold, a researcher at the University of Potsdam.
“Thus, there’s a necessity to reevaluate other continental European hippo fossils typically considered to belong to the last interglacial period.”
“This study provides significant new insights that compellingly demonstrate that the Ice Age was not uniform everywhere but rather that regional specificities contributed to a complex picture,” remarked Professor Rosendahl.
“It would be intriguing and valuable to further examine other heat-loving animal species that have so far been linked to the last interglacial.”
This result was published in the journal on October 8, 2025, in Current Biology.
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Patrick Arnold et al. Ancient DNA and dating evidence show hippos dispersed into central Europe during the last ice age. Current Biology published online October 8, 2025. doi: 10.1016/j.cub.2025.09.035
Source: www.sci.news
