Fossils of an unknown 20-million-year-old dolphin species have been discovered in Switzerland
3D images of what dolphins looked like in ancient times - image from the NBC website
A previously unknown species of dolphin swam in the oceans 20 million years ago, including the waters that covered Switzerland, today a landlocked country in the heart of Europe, researchers said.
At that time, Switzerland was part of an island landscape, its lower parts covered by an ocean teeming with fish, sharks, dolphins, mussels and sea urchins lining the sea floor.
The university said in a statement that after examining about 300 fossils of whales and dolphins found in Switzerland dating back to this period, researchers from the Institute of Paleontology at the University of Zurich discovered two previously unknown species.
The researchers combed fragments of teeth, vertebrae and bones found in layers of marine sediments, known as upper marine molasses, looking for bones that are less common than the inner ear, because they allow species to be classified.
"We were able to identify two families of dolphins that were not previously known in Switzerland," paleontologist Gabriel Aguirre said in the statement.
Using computed tomography, a 3D imaging technique, researchers were able to reconstruct the softer organs around the hard bones of the ear, creating 3D models of the ears. “This helped us better analyze the hearing ability of dolphins,” Aguirre said.
In the study, published on the scientific publishing website PeerJ, researchers determined that the extinct animals are related to sperm whales and ocean dolphins living today.
In late April, paleontologists found the remains of fossils of giant marine reptiles that became extinct a long time ago, in an unexpected place. These fossils were found at high altitudes in the Swiss Alps, and among them was the largest tooth of a giant fish lizard.
These "fish lizards" first appeared in the ocean about 250 million years ago, and are somewhat similar to dolphins with long bodies and small heads. They appeared after the Permian mass extinction, which wiped out more than 95% of marine species. But 200 million years ago, the giant ichthyosaurs became extinct and only the smaller, more dolphin-like ones survived until 90 million years ago.
Source: websites