A secret group of orcas has been discovered that could turn out to be an entirely new species.
They were first recorded in 1955 after 17 of these orcas beached on the coast of Paraparaumu, New Zealand.
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There were distinct differences from normal orcas, including different shaped heads, smaller white patches above their eyes and thinner, pointy dorsal fins.
At first, scientists thought these changes could be due a genetic abnormality. Then in 2005 researchers were shown images of orcas with the same distinct features - this time in the southern Indian Ocean, more than 9000 kilometres away.
This was evidence that the orcas were part of a widespread group - and possibly a new species. This January, an international team collected samples for genetic testing that will reveal the truth.
"We are very excited about the genetic analyses to come. Type D killer whales could be the largest undescribed animal left on the planet and a clear indication of how little we know about life in our oceans," said Bob Pitman, a researcher from NOAA Fisheries' Southwest Fisheries Science Center in La Jolla, California.
"These samples hold the key to determining whether this form of killer whale represents a distinct species."
The samples are expected to be analysed in the next few months.