Scientists at New Zealand have found a first-of-its-kind dolphin fossil. The specimen called Papahu taitapu may have been a close relative of the ancestor of modern-day dolphins and whales.
The specimen could help researchers re-construct the evolutionary history of dolphins, especially of species living in the Southern Hemisphere.
Researchers at University of Otago found a jaw, a skull and some other parts of the mammal in the Cape Farewell region of northern South Island, New Zealand. The fossil's name comes from 'Papahu'- the Maori name for dolphin.
According to the researchers, Papahu lived around 19-22 million years ago and were about two meters or 6 feet, about the size of modern dolphins.
Papahu had simple conical teeth and a wide head, according to fossil analysis conducted by Dr Gabriel Aguirre and Professor Ewan Fordyce, from the University's Department of Geology.
"Our study of structures of the skull and earbone suggest that Papahu could make and use high frequency sound to navigate and detect prey in murky water. They probably also used sound to communicate with each other," said Dr Aguirre in a news release.
The order cetacea includes whales, dolphins and porpoises. Currently, there are about 80 species of living whales.
The specimen can also be used to understand the relationship between dolphins and whales. Papahu skull is quite different from all other fossils found earlier, showing that dolphins were once quite varied.
"When we compared Papahu with both modern and fossil dolphins we found that it belongs in a diverse and structurally variable group of ancient dolphins that evolved and spread world-wide 19-35 million years ago. All of those ancient dolphins including Papahu and others, such as shark-toothed dolphins, are now extinct," said Professor Fordyce.
The study is published in the Journal of Vertebrate Paleontology.