The researchers were able to get good quality DNA from tissue samples from only one specimen. For the others, they drilled the bones of the whales in order to analyse short fragments of 'ancient DNA' relying on techniques commonly used with old sub-fossil material from extinct species.
The researchers also studied all other known beaked whale species to confirm the distinctiveness of Deraniyagala's whale, including six specimens of the closely related, gingko-toothed beaked whale.
"A number of species in this group are known from only a handful of animals, and we are still finding new ones, so the situation with Deraniyagala's whale is not that unusual," Dr Dalebout says.
"For example, the ginkgo-toothed beaked whale, first described in 1963, is only known from about 30 strandings and has never been seen alive at sea with any certainty. It's always incredible to me to realise how little we really do know about life in the oceans. There's so much out there to discover. "
Over the last 10 years or so, two other new beaked whales have come to light; both through research in which Dr Dalebout was involved. In 2002, Mesoplodon perrini or Perrin's beaked whale, was described from the eastern North Pacific, and in 2003, Mesoplodon traversii, the spade-toothed whale, was described from the Southern Ocean. Both species are known from only about five animals each.
With the re-discovery of Mesoplodon hotaula, there are now 22 recognised species of beaked whales.
|Contact: Deborah Smith|
University of New South Wales