Dolphins swam the oceans six MILLION years earlier than originally thought, ancient skull reveals

• Studies of a skull fragment have revealed it to be from an ancient dolphin
• Research was led by Mizuki Murakami of the Waseda University in Japan
  
• The fossil was first found in 1970 but its origin has only just been revealed
• It belonged to a species of dolphin that existed up to 13 million years ago
• The finding makes dolphins 6 million years older than previously thought
  
• Names Eodelphis kabatensis the species is an important evolutionary link

 
Dolphins may have been swimming the Earth’s oceans for six million years longer than previously thought, suggests a new study.
They are the most diverse family of living marine mammals and include species such as the Bottlenose dolphin and the killer whale.
However, their early evolution and fossil record has been steeped in mystery due to lack of good specimens.
Now a new study, published in the Journal of Vertebrate Paleontology, has re-described the oldest species of dolphin with a new name: Eodelphis kabatensis.
Although the partial skull was previously described in the 1970s, researchers behind the new paper say the scientific community largely overlooked it.
And the new re-description has important implications for the evolutionary history of dolphins.