Scientists have identified a new fossil dolphin species with tusk-like teeth, different from anything seen in today's dolphins or whales.
The specimen, named Nihohae matakoi, was excavated in 1998 in North Otago and has been in storage ever since. It was only recently studied.
"This is a dolphin that has very special teeth, we don't see anything like it in any other dolphin or whale or any other animal living today," University of Otago faculty of dentistry senior lecturer Dr Carolina Loch said.
What makes this Nihohae matakoi so special is the condition it is in.
"The skull was preserved beautifully, the quality is amazing and pretty remarkable for something that's 25 million years old," said Dr Loch.
The strange horizontal teeth prompted researchers to question what they were used for.
"Maybe it was sifting through sand or algae or whatever it might be to try and flush out fish and the sort before eating them," lead author Dr Amber Coste said.
Or more violent reasons.
"Slashing its head wildly side to side, injuring stunning or killing some prey, which it could then swallow up much more easily," Dr Coste said.
A move that played a part in naming the new fossil species.
"Nihohae matakoi essentially means long face slashy teeth," Dr Coste said.
The extraordinary teeth and feeding technique have not survived evolution.
"It's something we don't see any other modern species doing and probably wasn't very effective because it didn't persist," she said.
But the Nihohae matakoi has added a piece to the puzzle about past life on the planet.
"[It] shows the relevance and importance of this place in the world to understand the history of the planet 25 million years ago," Dr Loch said.
Providing a bite-sized portion of the history of ancient New Zealand.
