Systematics, phylogeny, and zoogeography of the lizard genus Diplodactylus Gray (Gekkonidae)

Abstract

Each of the 14 genera now referred to the subfamily Diplodactylinae (Naultinus, Hoplodactylus, Heteropholis, Bavayia, Rhacodactylus, Eurydactylodes, Pseudothecadactylus, Carphodactylus, Phyllurus, Nephrurus, Oedura, Diplodactylus, Rhynchoedura, and Crenadactylus) is characterized on the basis of its internal and external morphology. The type species, referred species, and distribution are given for each genus. The Diplodactylinae are divided into two tribes primarily on the basis of differences in the arrangement and number of preanal pores and the size and shape of the nasal process of the premaxilla. The Carphodactylini includes Naultinus, Hoplodactylus, Heteropholis, Bavayia, Rhacodactylus, Eurydactylodes, Carphodactylus, Pseudothecadactylus, Phyllurus, and Nephrurus. The Diplodactylini includes Diplodactylus, Oedura, Rhynchoedura, and Crenadactylus. The Carphodactylini appear to be more primitive than the Diplodactylini. Carphodactylus may be close to the ancestral stock of the subfamily. Phyllurus and Nephrurus seem to be closely related to Carphodactylus. Pseudothecadactylus is considered to be closely related to the New Caledonia-Loyalty Islands radiation, which consists of Eurydactylodes and Rhacodactylus, and probably Bavayia. The New Zealand genera Hoplodactylus, Heteropholis, and Naultinus seem to form a natural group which is related to the New Caledonian genera. Crenadactylus is probably only distantly related to the other genera of the Diplodactylini. Rhynchoedura seems to be related to the stenodactylus group of Diplodactylus, while Oedura shows an affinity to the strophurus group of that genus. Geographically, the Diplodactylinae is restricted to the Australian Region (Australia, New Caledonia, Loyalty Islands, and New Zealand). The ancestral stock of the subfamily probably originated in south-east Asia and dispersed toward Australia by way of the Indo-Australian Archipelago during the upper Cretaceous. It is postulated that the subfamily reached Australia (and continental New Guinea) by Palaeocene- Eocene time.