Begin at the Beginning

Or at least at that point in deep time, some 60 to 80 million years ago (MYA), when what we now know as New Zealand broke away from Australia.

The science of plate tectonics suggests that the supercontinent of Gondwana formed around 170 million years ago and began splitting apart about 130 MYA as shown in the stylized map below. It was the southeastern region of Gondwana (diagonal lines) that acted as the platform for the evolution of life that would populate Australia & New Zealand.

Between 80 and 60 MYA, what would eventually become New Zealand began to drift away from that part of eastern Gondwana comprising Antarctica and Australia. The last piece to separate from New Zealand was New Caledonia which explains why the two have a number of species in common although evolution continued to take its divergent paths after separation.

from Gibbs, The Ghosts of Gondwana, 2006.

Isolated from the rest of the world’s land masses, life in New Zealand took its own distinctive path, leading scientists such as Jared Diamond to assert that “New Zealand is as close as we will get to the opportunity to study life on another planet” and Tim Flannery to call it “a completely different experiment in evolution from the rest of the world”.

Was this Moa’s Ark – a hermetically-sealed time capsule of life from Gondwana plus evolution over 60 million years – or was it also the result of later dispersals before man introduced new species?