- See also: Triassic Divergence
Topography and position in the oceans give the islands of New Zealand an unusual biome found in few other places on Earth: a temperate rainforest.
The flora of New Zealand, much like the fauna, is not quite like that found anywhere else on Earth. Its isolation and unique climate lead to conditions allowing hundreds of endemic species.
New Zealand's sphenodonts are, with the exception of the aotearosaurids, the largest terrestrial animals on the islands. There are a few herbivorous species – and at least one genus of mid-sized carnivore – but most sphenodonts in New Zealand are insectivores as they are in the rest of the world.
Australosphenodon is a common genus of lizard-like sphenodont found in Australia, New Caledonia, and New Zealand. Its diet consists primarily of insects, small to large.
Aotearoasphenodon is the largest genus of endemic sphenodont in New Zealand. It is carnivorous, feeding on smaller sphenodonts, pterosaurs, and the occasional small aotearosaur.
Herbosphenodon is the genus containing all herbivorous species of sphenodont on New Zealand, as well as a few basal insectivorous species.
The Aotearoasauridae are the dominant terrestrial animals of New Zealand, and they, as a group, are found nowhere else on Earth. The semi-aquatic nothosaurs were among the first animals to return to the coastline of New Zealand after its extinctions, and they returned to a terrestrial mode of life before an impressive radiation into a number of niches. The taxonomy of New Zealand's nothosaurs seems to line up well with dietary and environmental habit, though the relationhips among the individual groups are uncertain. The majority of these organisms are rather clumsy on land, but the lack of other terrestrial predators meant there was little necessity for speed.
These nothosaurs exist as semi-aquatic (to varying degrees) piscivores in and around New Zealand's rivers and lakes. Today, they are represented by two genera with a few species each.
Waitorekeus is the genus comprising small nothosaurs that live in a semi-aquatic fashon in New Zealand's rivers, lakes, and streams.
Piscatorosaurus is the genus comprising species of amphibosaurs that mostly live on land but use their long necks and fully-developed front claws to catch fish, usually in fresh bodies of water.
The Herbosaurinae are small to large herbivores in the forests of New Zealand. They tend to use their elongated necks to browse either high in the trees or in a large area along the ground.
Bratosaurus are generally the tree-browsing aotearosaurs and the largest terrestral animals in New Zealand.
Rubosaurus is the genus of smaller herbosaurs that generally feed on low bushes and herbaceous plants.
Granosaurus is a genus of derived seed-cracking herbosaurs with specialized claws for digging in the soil.
Aotearosaurinae contains one genus of carnivorous aotearosaurs.
Aotearosaurus is the only genus of midsize terrestrial carnivore present in New Zealand. These animals are not large enough to feed on the largest herbosaurids, but they can certainly capture smaller aotearosaurs and large sphenodonts.
Though represented by common groups, the pterosaurs of New Zealand have adapted to many unusual roles. There are no truly terrestrial pterosaurs on the islands (due to their clumsy terrestrial motion), but many have used the ability to stay on the ground for long periods of time to develop unique lifestyles.
The "perching pterosaurs" are by far the most common on New Zealand. They are typically very small, but the isolation of New Zealand has led to a greater diversity of diets than is usually found in the rest of the world.
Aotearopasser is the largest genus of the perching pterosaurs found in New Zealand. They have a variety of dietary habits, but most feed on seeds.
Granopterosaurus is the short-snouted genus of New Zealand pterosaurs specialized for cracking large seeds.
Cutolaceratus is an unusual genus of endemic pterosaur specialized in tearing bark off of trees to search for insects and softer plant matter.
While most of the carnivorous pterosaurs are limited to eating only what they can carry away, those on New Zealand do not suffer from this limitation because of the lack of large terrestrial predators. This ability means that pterosaurs have become the only predators of the largest herbivores on the islands.
Aotearoraptor is the largest genus containing the largest pterosaurs found in New Zealand. They are the only predators of the largest aotearosaurs, but they almost always feed on the ground after killing their prey with divebombing attacks.
The oceanic pterosaurs of New Zealand are not markedly different from those of the larger landmasses, as a continual migration of animals to and from the rest of the world is present. A few endemic species are present, however, especially in areas with bodies of fresh water.
Fluvopterosaurus is the genus containing the freshwater ichthyopterosaurs of New Zealand. There are only a few species, but they are very common around the larger bodies of water on the island chain.