Courtesy of Mizuki Murakami
A dolphin first described from a fossil skull discovered in the 1970s has gotten a new name but still retains the title of oldest true dolphin species identified to date. Now called Eodelphis kabatensis, the creature swam the seas 8.5 million to 13 million years ago, a few million years before ancestors of spinner dolphins and others in the Stenella genus evolved.
As a result, the older creature should not have been a part of the Stenella genus and needed a new name, researchers report May 6 in the Journal of Vertebrate Paleontology. Giving E. kabatensis a new name can also reconcile the gap between molecular studies showing that true dolphins started to diversify 9 million to 12 million years ago and other fossil evidence dating the emergence of the animals to only 6 million years ago, the scientists say.