Sun, sea and dwarf hippos: the Mediterranean is a surprising palaeontological paradise

It's a popular holiday destination for many, but few know that the region's ancient history extends well beyond churches and ruins

With the sparkle of the holiday season now a distant memory, the fifty shades of January have many of us longing for the sun-soaked days of summer. The Mediterranean islands, rich in history and culture, fringed by sandy beaches and surrounded by deep blue waters, are a popular holiday destination. But few know that the earth below that picturesque tavern or idyllic beach holds exciting palaeontological discoveries.

The Mediterranean Sea arose from a western branch of the Tethys Ocean that separated the two supercontinents Laurasia and Gondwana during much of the Mesozoic. When Gondwana broke up in several continents (a protracted process that started over ~170 million years ago), the African plate moved northwards and collided with the Eurasian plate, eventually closing off this part of the Tethys on what is now the eastern border of the Mediterranean. During the Miocene, around 6 million years ago, the connection between the Mediterranean basin and the Atlantic Ocean closed by the uplift of mountainous ridges between western Africa and the Iberian Peninsula. Without the influx of water from the Atlantic, evaporation greatly exceeded precipitation and river influx, and the Mediterranean nearly dried up. This event is known as the Messinian salinity crisis, as salinity in the remaining waters greatly increased. At around 5.3 million years ago, the western border breached (forming the Strait of Gibraltar) and water gushed in. Although scientists disagree about the speed with which the water flooded in, some estimates suggest it may have taken less than two years to refill the entire Mediterranean (Garcia-Castellanos et al., 2009).