Landlocked Switzerland was home to previously unknown species of dolphins 20 million years ago, new research has found.

During this period, part of Switzerland, known as the Upper Marine Molasse, was covered by an ocean teeming with prehistoric fish, sharks, dolphins, mussels and sea urchins. Among them were two species of dolphins that scientists have recently been able to identify.

Paleontologists at the University of Zurich made the discovery by examining 300 fossils of whales and dolphins that swam around Switzerland at this time.

Amid assorted vertebrae and teeth were found bones from the inner ear, which are extremely rare but allow individual species to be classified.

“We managed to identify two families of dolphins previously unknown in Switzerland,” paleontologist Gabriel Aguirre said in a statementExternal link.

The extinct creatures are related to today’s sperm whale and oceanic dolphins.

Using micro-computed tomography, the team was able to reconstruct softer organs, re-model the ears of the dolphins and even analyse their hearing ability.

The research material of the discovery has been published on the PeerJ scientific publishing websiteExternal link.

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