The Rhine is five million years older than first thought: Age of the river corrected based on fossils

The accompanying study is published May 16 in the journal PLoS ONE.

The Rhine is not an unknown entity in Europe -- on its journey to the North Sea it flows through Switzerland, Austria, Germany and the Netherlands. In addition, the catchment area of the river, which is around 1,233 kilometres long, also encompasses almost all of Luxembourg as well as small parts of Belgium, France, Liechtenstein and Italy. Yet as famous as the river may be, its original age is still disputed.

"Up to now it has been assumed that the Proto-Rhine is around ten million years old," explains Prof. Madelaine Böhme, leading author of the study and head of the HEP working group "Terrestrial Palaeoclimatology," and continues: "But based on our examination of fossils from a site near Sprendlingen we now believe that the river is at least five million years older."

The mammalian fossils in the Sprendlingen and Eppelsheim areas have been considered for 200 years by vertebrate palaeontologists to be the yardstick for the Neogene -- the time span between 23 million and around 2.5 million years ago. The sites became famous around the world for the first ever discovery of a fossil ape (1822) and the first scientific descriptions of 19 large mammal species in the early 19^th century.

The allocation of a time period to the Deinotherium sands that were found there -- which contain numerous other fossils along with the teeth and bones that provided the name of the proboscidean -- has often been the subject of scientific debate.

"For this reason we examined a new sample with over 300 mammalian fossils, leaves and fossilized wood. In the process we found the teeth and bones of different deer species that lived in Central Europe at the beginning of the Middle Miocene -- in other words, in the period between 14 and 16 million years ago, " explains Böhme. "The results of the examinations of fossil plant residues that were found above and below the mammalian sites reinforce our conclusions."

The results have immediate consequences for the understanding of the development of the Main Basin and the Upper Rhine dig in geological history. Because the findings were made in the oldest known deposits of the Rhine, it must also be at least five million years older.

The conclusions of the Senckenberg scientists have an impact upon the entire chronological categorization of the flora and fauna of the Middle to Late Miocene -- this, despite the fact that until now the sites near Sprendlingen had been a timing determinant for palaeontologists only.