Lizards of the Genus Emoia (Scincidae) with Observations on their Evolution and Biogeography

The 72 recognized species of the lizard genus Emoia (Scincidae) are described; 13 of these are new: E. coggeri, E. cyclops, E. digul, E. irianensis, E. jamur, E. paniai, E. brongersmai, E. montana, E. pseudopallidiceps, E. erronan, E. isolata, E. pseudocyanura, and E. rennellensis. Three new subspecies – E. arnoensis nauru, E. atrocostata australis, and E. physicae pupari – are also described. A new status is recognized for eight species or subspecies: E. atrocostata freycineti. E. bogerti, E. maxima, E. obscura, E. oribata, E. pallidiceps mehelyi, E. popei, and E. veracunda.

Eight species groups are recognized on morphological grounds. Three (baudini, cyanogaster, and physicae) are known only from New Guinea and adjacent islands. Two groups (ponapea and adspersa) have limited ranges in Micronesia and Samoa. The samoensis Group occurs in the Samoa, Tonga, Fiji, Vanuatu, and Solomon islands. The cyanura Group has two areas of endemism: the Solomon Islands and islands to the west of New Guinea. The atrocostata Group also exhibits two areas of endemism: a primary one in Micronesia and isolated endemics in southeast Asia and on Christmas Island. Only two relatively wide-ranging species have reached Australia, in the northeastern Cape York area. Four species (or superspecies), one in the atrocostata Group, one in the baudini Group, and two in the cyanura Group have extensive ranges – these distributions are interpreted as the result of more opportunistic dispersal, at times probably with the aid of man.

The distribution patterns of the groups and the evidence of radiation within the currently occupied areas correlate with recent hypotheses concerning the plate tectonics of the southwest and western Pacific regions.