Although the evidence is rare, fossils reveal that there were Mesozoic reptiles, including dinosaurs in New Zealand. Possibly because it lacks the right conditions for fossilization, only fragmentary dinosaur remains have been found there. These fossils are often only a single bone or a piece of a bone, and thus the dinosaurs' species cannot be identified. By comparing the fossils with other, more complete remains from other areas it can be inferenced which family or order a given fossil belonged to. Marine fossils are more common than fossils of land animals in New Zealand because dead animals and plants are easily preserved in sand and mud. Therefore, some fossils of marine reptiles are complete enough to be assigned to a specific genus or species.
So far, there have been fossils found in New Zealand that have been identified as coming from:
See also: List of Australian and Antarctic dinosaurs.
| Name | Time | Formation | Location | Notes | |
|---|---|---|---|---|---|
| Maastrichtian (Haumurian) | Tahora Formation | Probably a nodosaurid similar to Kunbarrasaurus[1] | |||
| Compsognathid? | Tithonian (Puaroan or Ohauan) | Huriwai Measures Formation | Waikato River, Waikato | Known from phalanges. Associated with possible coprolites. It can’t be identified for certain, but the bones superficially resemble Compsognatids[2] | |
| Ornithopod[3] | Maastrichtian (Haumurian) | Tahora Formation | Possibly an elasmarian | ||
| Joan Wiffen's theropod | Maastrichtian (Haumurian) | Tahora Formation | Refer to the linked article for sources | ||
| Maastrichtian (Haumurian) | Tahora Formation | Known from a rib [4] |
Dinosaurs that lived in the Ross Dependency, a part of Antarctica within the Realm of New Zealand, include the tetanuran Cryolophosaurus. The Ross Dependency, unlike the Chatham Islands, is not actually part of New Zealand, and this is why it is excluded from the list above until sufficient evidence shows that it entered what was the sector of Gondwana that is now New Zealand. Newer fossils from a Cretaceous-Paleogene boundary fossil formation known as the Takataka Grit in the Chatham Islands include six or seven (possibly more) bones from dinosaurs, as well as numerous bones from early birds, but more information is needed about these to add them to the list.
Fossils of other reptiles from the Mesozoic Era have also been found in New Zealand. These creatures include:
| Name | Period | Formation | Area | Notes |
|---|---|---|---|---|
| Eidolosaurus | A mosasauroid outside of the mosasaurid family | |||
| "Hector's ichthyosaur" | Mount Potts | The first ichthyosaur reported from New Zealand. Known from ribs, a partial humerus, a possible tooth and vertebral centra, the largest of which measured 45 cm (18 in) in diameter. With centra almost twice the diameter of those belonging to the largest ichthyosaur with preserved vertebrae, Shastasaurus sikanniensis, it may have been among the largest vertebrates to ever exist.[5] These specimens can no longer be located, and may have been lost.[6] A Canterbury Museum presentation mentioned unprepared giant ichthyosaur bones from Mount Potts.[7] | ||
| Kaiwhekea | Late Cretaceous | Katiki Formation | An aristonectine plesiosaur[8] | |
| Liodon | A dubious genus, the maximum length of this species is . | |||
| Mauisaurus | Late Cretaceous | A dubious genus; largest plesiosaur in New Zealand[9] | ||
| Moanasaurus | Late Cretaceous | Largest mosasaur in New Zealand[10] | ||
| Prognathodon | A large mosasaur[11] | |||
| Discovered 1987.[12] Possibly an azhdarchid. | ||||
| Taniwhasaurus | Late Cretaceous | Conway Formation | A mosasaur[13] | |
| Tuarangisaurus | Late Cretaceous | Tahora Formation | An elasmosaurid[14] | |