National Institute Of Water & Atmospheric Research (NIWA) to identify.
But much of the teeming NIWA sea urchin collection had gone unidentified since the 1960s.
Now, they've been pinpointed for the first time, thanks to the studious efforts of deep water fisheries scientist Owen Anderson.
"There are many different kinds of urchins, which I hadn't appreciated before I started researching kina (sea urchin), but now I'm hooked," he said.
"I love the symmetry and detail of the shell plating. They're very beautiful."
Mr Anderson had the privilege of naming the seven new species - Araeosoma bidentatum, Araeosoma migratum, Araeosoma anatirostrum, Araeosoma tertii, Araeosoma leppienae, Araeosoma bakeri and hapalosoma amynina.
He is now researching, identifying, and describing a further seven species.
The research resolves confusion around the Tam O'Shanter species Araeosoma coriaceum, supposedly recorded off northern New Zealand by the Challenger Expedition in 1874 and again recorded 100 years later in the Hauraki Gulf.
Examination of old specimens, new material, and original descriptions led to the conclusion that the Challenger specimen had been mis-labelled with its true locality unknown.
The Hauraki Gulf specimen, therefore, had been mis-identified, and is now known as Araeosoma bakeri.
The newly-identified group includes the giant Araeosoma alternatum - which grows up to 23cm in diameter.
It was known from a single specimen, found in the Indian Ocean near Somalia in 1899, and then stored in a Berlin museum where it was destroyed in World War Two.
"The good news is that this species was rediscovered alive and well, relatively rare but widespread around New Zealand," Mr Anderson said.
Around 50 species of Tam O'Shanter sea urchins are known globally, with nearly a third of them found in New Zealand waters.
Some of the newly-found species are now on display next to the giant squid at Te Papa museum in Wellington.
