The New Zealand Scincidae (Reptilia: Lacertilia); a taxonomic and zoogeographic study

This revision of the New Zealand Scincidae recognises 22 species, in the genera Leiolopisma Duméril & Bibron and Cyclodina Girard. The following species are redescribed: L.fallai McCann; L. suteri (Boulenger); L. smithi (Gray); L. homalonotum (Boulenger); L. moco (Duméril & Bibron); L. infra‐punctatum (Boulenger); L. striatum (Buller); L. zelandicum (Gray); L. nigriplantare (Peters); L. lineoocellatum (Duméril & Duméril); L. grande (Gray); L. otagense McCann; L.(?) fasciolare (Girard); C. ornata (Gray); C. aenea Girard; C. oliveri (McCann); C. alani (Robb); and C. macgregori (Robb).

L.(?) fasciolare is included in Leiolopisma only provisionally pending further examination; doubts regarding its inclusion in the New Zealand herpetofauna are raised. Leiolopisma gracilicorpus, L. chloronoton, L. acrinasum, and Cyclodina whitakeri are erected as new species. Only 2 subspecies are recognised, in L. nigriplantare. L. n. nigriplantare includes animals described earlier as L. dendyi (Boulenger) and L. turbotti McCann, and L. n. maccanni includes those animals referred to under the name L. zelandica by McCann (1955). Two forms of L. otagense are recognised, but are not accorded subspecific status. L. pachysomaticum Robb, 1975 is reduced to synonymy with Cyclodina oliveri. Hinulia variegata Buller is declared a nomen dubium.

Electrophoretic studies of lactate dehydrogenase (LDH) isozymes and haem compounds appear to confirm the species recognised on morphological characteristics. Analyses of LDH isozymes suggest close phylogenetic relationships within 3 groups of species: Leiolopisma striatum and L. zelandicum; Cyclodina ornata and C. aenea; and C. oliveri, C. alani, and C. whitakeri. Investigations into the relative evolutionary stability of haemoglobins and morphological characters indicate that rates of evolution may differ, both within and between species. Evidence is presented to show that the evolution of haemoglobins cannot necessarily be taken to have occurred at similar rates overall in the New Zealand skink species.

It is suggested that Cyclodina arose from a pre‐Leiolopisma stock before the development of the palpebral disc characteristic of Leiolopisma. The genus Leiolopisma is thought to have arisen in a region north of Australia, and to have given rise in that area to 2 early offshoots, the first represented today by L. spenceri and L. palfreymani and the second by L. telfairi and L. lichenigera. Subsequent dispersal of the genus is believed to have been via the New Caledonian region, where further divergence resulted in forms now present in Australia (L. coventryi and L. entrecasteauxi) and New Zealand (the entire Leiolopisma fauna). The New Zealand Leiolopisma species are all endemic at the specific level, and are likely to represent late Pliocene invasions. The Australian Leiolopisma species characterised by fused frontoparietals are considered to represent a second invasion of that continent from the New Caledonian region.

Cyclodina probably reached New Zealand via the New Caledonian region, at latest by the early Pleistocene. The genus has not been recorded from outside New Zealand (although revision of the generic placement of L. euryotis, from New Caledonia, is necessary owing to its strong affinities with Cyclodina).

Uncertainty as to the effects of early Pleistocene glaciations on the distribution and isolation of the New Zealand species inhibits discussion of their zoogeography. Nevertheless, 3 geographic groups of species are recognised in the New Zealand Leiolopisma fauna. The northernmost is believed to have arisen from invaders from the New Caledonian region; the central and southern groups from an easterly movement of invaders from Australia. L. suteri probably represents yet another invasion.

The present distribution of species indicates that the following refuges persisted in the South Island during the last Pleistocene glaciation: coastal Fiordland; Southland and Stewart Island; Otago and Banks Peninsulas; and the Nelson/Marlborough Sounds region. Isolation of populations in the vicinity of the Otago and Banks Peninsulas has probably been important in the divergence of 2 forms within L. otagense. Haem banding patterns suggest that relict populations of L. nigriplantare exist at Te Anau and on Stewart Island, and a post‐Pleistocene reinvasion of the central South Island by that species is indicated. Subspeciation of L. nigriplantare on the Chatham Islands is also thought to have occurred after the Pleistocene.

Notes

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