Paleontologists have recently made an extraordinary discovery in landlocked Switzerland: two new species of dolphin dating back to 20 million years ago.

Ancient dolphin species 

Located in the heart of Europe, Switzerland is entirely landlocked. Millions of years ago, however, the area used to be part of an island landscape with the surrounding water brimming with marine life, such as sharks, whales, and dolphins.

As part of the study, paleontologists from Zurich University analyzed around 300 fossils of whales and dolphins that were found in Switzerland from that period. They eventually discovered two entirely new dolphin species from prehistoric times.

Using rare ear bones to classify species

Among the examined fossils were fragments of teeth, vertebrae, and bones found in layers of marine sediment, known as the Upper Marine Molasse. However, the main focus of the study was bones from the inner ear, as these are often unique enough to classify individual species. The challenge though is that these types of bones are hard to find in fossils.

The researchers still succeeded in finding an interesting discovery. “We managed to identify two families of dolphins previously unknown in Switzerland,” paleontologist said paleontologist Gabriel Aguirre.

Thanks to micro-computed tomography — a 3D imaging technique — the scientists were able to reconstruct the softer organs around the hard ear bones to create 3D models of the ears. “This helped us better analyze the dolphins’ hearing ability,” Aguirre said. The findings indicated that the two new species of dolphins were closely related to the sperm whales and ocean dolphins of today.

Source study: PeerJ — First records of extinct kentriodontid and squalodelphinid dolphins from the Upper Marine Molasse (Burdigalian age) of Switzerland