Aotearoa / New Zealand: a unique beginning
By breaking away from the super-continent Gondwana, Zealandia became an isolated environment in which unique species of flora and fauna evolved and thrived.
The origins of our unique ecology
Eighty million years ago tectonic activity started to break up the super-continent Gondwana. Through this process a smaller continent, known as Zealandia, was created that would eventually form the land of Aotearoa / New Zealand.
The world’s biota (or living things) was very different when Zealandia broke away from Gondwana. The ancestors of many of our present-day plants and animals travelled with the continent, and then continued to evolve here in isolation. The kauri and podocarps such as rimu and tōtara, the southern beeches, wētāpunga and tuatara are all endemic taxa (only found here) that have ancient lineages back to this time.
A changing landmass
Zealandia’s landmass continued to change following its split from Gondwana. Large at the time of separation, Zealandia became progressively smaller and more subdued during the Oligocene period (33-23 million years ago). At that time, apart from a chain of islands, much of it lay below sea level.
Following the Oligocene period, new land was lifted out of the sea by tectonic movements or formed through volcanic activity.
Evolution in isolation
As more land appeared, new species of plants and animals capable of dispersing across the widening Tasman Sea arrived.
Now separated from a world increasingly dominated by mammals, unique species evolved in a land isolated from mammalian predation and browsing.
Numerous species of flightless and ground-dwelling birds evolved, including nine species of moa ranging in size from the turkey-sized small bush moa up to the 250 kg giant moa.
The largest known raptor, the Haast eagle, preyed on moa and other large ground birds.
The forest floor was home to many ground-foraging species. These included bats, which scuttled around on all fours, and giant wētā, filling the niche that small rodents hold in other parts of the world. There were also many species of lizards and several species of primitive frogs.
The coast and marine environment supported large populations of seabirds, seals and whales.
A diverse flora with a high proportion of endemic plants evolved to occupy Aotearoa’s wide range of environments, from the sea coast and wetlands through to subtropical, temperate, and alpine habitats.
