'World's rarest whale' washes up on beach and it's only the sixth sighting in history

A whale suspected of being the 'world's rarest' species has washed ashore on a New Zealand beach.

On 4 July, New Zealand's Department of Conservation (DOC) were called to a beach in Otago located near Taiari Mouth after it received reports of a whale having been washed up onto the shore.

And when members of the department arrived at the scene, they quickly realised this might not just be any sort of a whale, but a 'whale so rare only six specimens have ever been known to science'.

Marine-mammal experts from the DOC and Te Papa attended the beach, a media release from the department of Conservation Te Papa Atawhai reports.

The whale measures five-meters long and was quickly identified as being male, with its color patterns and the shape of its teeth, skull and beak leading experts to believe it could belong to the spade-toothed whale species (Mesoplodon traversii) - the rarest species of beaked whale.

"A species so rare next to nothing is known about them," the report emphasises.

The species was first discovered and named after a partial jaw was located on Pitt Island, New Zealand in the early 1870s.

The whale was found ashore a beach in Otago, New Zealand (DOC)

A part of a skull believed to belong to another spade-toothed whale was found in the 1950s on White Island, New Zealand and another in 1993 on Robinson Crusoe Island, Chile.

The first complete specimens of the species were discovered in 2010 when a mom and calf were found stranded on Opape Beach in Bay of Plenty, New Zealand.

And according to DOC Coastal Otago Operations Manager Gabe Davies there have only been 'six samples' ever 'documented worldwide' since the 1800s.

"Two more recent findings, in Bay of Plenty and north of Gisborne, helped describe the colour pattern of the species for the first time," DOC added.

A female spade-toothed whale was found washed ashore in 2010 (Kirsten Thompson et al / Current Biology)

Davies said: "Spade-toothed whales are one of the most poorly known large mammalian species of modern times. [...] From a scientific and conservation point of view, this is huge."

Genetic samples from the whale have been taken by the DOC and Te Rūnanga ō Ōtākou and sent to the University of Auckland for DNA analysis to confirm the whale is indeed a spade-toothed whale.

The whale was removed from the beach and has been placed in cold storage for preservation purposes.

Te Rūnanga ō Ōtakou chair Nadia Wesley-Smith stated: "It is important to ensure appropriate respect for this taoka is shown through the shared journey of learning, applying mātauraka Māori as we discover more about this rare species."