It is far from unknown for various tropical species to come ashore on Far North beaches, but Kaitaia man Phil Cross cannot begin to understand how a coconut crab turned up on 90 Mile.
The crab's remains had been well pecked by seagulls by the time he found it, south of Waipapakauri Ramp, but were clearly identifiable.
The coconut crab is found throughout the Indian Ocean and Central Pacific.
The largest of the land crabs, which can live for 60 years, growing to more than a metre long and more than 4kg in weight, it cannot swim and will drown if immersed in water.
"That begs the question, how on earth did it get here?" Mr Cross said.
The eggs were laid at the water's edge, and larvae, which spent the first few weeks of their lives in the sea, would attach themselves to floating objects, although that did not seem to be a feasible explanation.
Mr Cross was able to identify the specimen as female, and is now wondering if the Far North had become home to a "secret colony."
He was certainly keen to hear from anyone else who had seen or found one.
The coconut crab is regarded throughout its range as a delicacy, and in some cultures as an aphrodisiac, and human predation has driven it to extinction in some places. It is endangered, and protected, in others.
It does eat coconuts, removing the husk and breaking into the shell with its large claws, a process that can take days, or carrying them into trees and dropping them (then jumping to the ground after them).
The species is omnivorous, however, also eating fruit, seeds, other crabs (including its own kind) and carrion.
One has been credited with killing and eating a rat, while there is a theory that they might have consumed aviatrix Amelia Earhart's remains, and hoarded her skeletal remains in their burrows.