A Review of the Fossil Record of New Zealand Lizards

Abstract

The fossil record of squamates in New Zealand is scant, and this chapter represents the first systematic review of the available information for this reptile group in New Zealand. The oldest fossil squamates are found in the Early Miocene (19–16 mya) St Bathans Fauna. The material represents skinks referred to Eugongylinae similar to extant species of Oligosoma and geckos referred to Diplodactylidae, which differ little from extant New Zealand geckos. No other squamates are represented in the St Bathans Fauna. The Early Miocene St Bathans skinks and geckos formed part of a fauna that was similar to the recent prehuman New Zealand fauna as it was dominated by birds and included sphenodontids and leiopelmatid frogs, but differed markedly by the additional presence of a crocodilian, terrestrial turtles and greater mammalian diversity. A squamate fossil record is then unknown until the last 50,000 years of the late Quaternary. This late Pleistocene to Holocene fauna, however, documents the natural, undisrupted biota that was encountered and decimated by humans and the species they introduced. Fossil squamates are relatively common, but little studied. Notably, they document the former widespread presence of a suite of large forms. Among skinks, these include two extinct taxa in the Northland region of North Island, including Oligosoma northlandi, the largest skink known from New Zealand. In Northland and elsewhere on the North Island, fossils attest to the more widespread presence of Oligosoma alani, O. whitakeri, O. macgregori and O. oliveri. In both North and South Islands, Hoplodactylus duvaucelii was widespread. The available information for the kawekaweau (Hoplodactylus delcourti) is reviewed, and the lack of fossil evidence for it is discussed.