Super squid surfaces in Antarctic
"Now we know that it is moving right through the water column, right up to the very surface and it grows to a spectacular size."
Mesonychoteuthis hamiltoni was first identified in 1925 after two arms were recovered from a sperm whale's stomach.
There have only ever been six specimens of this squid recovered: five have come from the stomachs of sperm whales and the sixth was caught in a trawl net at a depth of 2,000 to 2,200 metres.
"Now we can say that it attains a size larger than the giant squid. Giant squid is no longer the largest squid that's out there. We've got something that's even larger, and not just larger but an order of magnitude meaner."
This squid has one of the largest beaks known of any squid and also has unique swivelling hooks on the clubs at the ends of its tentacles.
This combination allows it to attack fish as large as the Patagonian toothfish and probably to also attempt to maul sperm whales.
The specimen, which was caught in the past few weeks in the Ross Sea, has a mantle length of 2.5 metres. That is a larger mantle than any giant squid that Dr O'Shea has seen and this specimen is still immature, the NZ scientist believes.
"It's only half to two-thirds grown, so it grows up to four metres in mantle length." By comparison, the mantle of the giant squid, Architeuthis dux, is not known to attain more than 2.25 metres.
The squid researchers are calling Mesonychoteuthis hamiltoni the "colossal squid".
"We feel that colossal conveys both the size and the aggressiveness of the animal.
"This animal, armed as it is with the hooks and the beak that it has, not only is colossal in size but is going to be a phenomenal predator and something you are not going to want to meet in the water."