Revision of the giant geckos of New Caledonia (Reptilia: Diplodactylidae:
Rhacodactylus)
Mniarogekko gen. nov.,
Paniegekko gen. nov.,
Correlophus belepensis sp. nov.,
Mniarogekko jalu sp. nov.,
We employed a molecular phylogenetic approach using the mitochondrial ND2 gene and five associated tRNAs
(tryptophan, alanine, asparagine, cysteine, tyrosine) and the nuclear RAG1 gene to investigate relationships within the
diplodactylid geckos of New Caledonia and particularly among the giant geckos, Rhacodactylus, a charismatic group of
lizards that are extremely popular among herpetoculturalists. The current generic allocation of species within New
Caledonian diplodactylids does not adequately reflect their phylogenetic relationships. Bavayia madjo, a high-elevation
endemic is not closely related to other Bavayia or to members of any other genus and is placed in a new genus, Paniegekko
gen. nov. Rhacodactylus is not monophyletic. The small-bodied and highly autapomorphic genus Eurydactylodes is
embedded within Rhacodactylus as sister to R. chahoua. Rhacodactylus ciliatus and R. sarasinorum are sister taxa but are
not part of the same clade as other giant geckos and the generic name Correlophus Guichenot is resurrected for them.
Remaining New Caledonian giant geckos (R. leachianus, R. trachrhynchus, R. auriculatus) receive weak support as a
monophyletic group. Although the monophyly of Rhacodactylus (including Eurydactylodes) exclusive of Correlophus
cannot be rejected, our results support the recognition of a R. chahoua + Eurydactylodes clade separate from
Rhacodactylus sensu stricto. Because of the distinctiveness of Eurydactylodes from R. chahoua (and other New
Caledonian ‘giant geckos’), we retain this name for the four species to which it has been consistently applied and erect a
new genus, Mniarogekko gen. nov. to accommodate R. chahoua. There is little genetic differentiation within the narrowly
distributed Corrrelophis sarasinorum, but C. ciliatus from southern New Caledonia are both genetically and
morphologically differentiated from a recently discovered Correlophus from the Îles Belep, north of the Grande Terre,
which is here described as C. belepensis sp. nov. Although only subtley different morphologically, the populations of
Mniarogekko from the far northwest of the Grande Terre and from the Îles Belep are strongly differentiated genetically
from M. chahoua populations in the central part of the Grande Terre and are described as M. jalu sp. nov. Rhacodactylus
auriculatus exhibits some genetic substructure across its nearly island-wide range in New Caledonia, but overall
divergence is minimal. Rhacodactylus leachianus exhibits low levels of divergence across its range and southern insular
forms previously assigned to R. l. henkeli are not divergent from southern Grande Terre populations. The few populations
of R. trachyrhynchus sampled are strongly divergent from one another and a specimen from Îlot Môrô near the Île des Pins
is especially distinctive. This specimen and others examined from Îlot Môrô are morphologically assignable to the species
described by Boulenger in 1878 as Chameleonurus trachycephalus and is recognized here as a full species. New diagnoses
are provided for each of the eight genera of endemic New Caledonian diplodactylid geckos now recognized. The results
of our study necessitate determinations of the conservation status of the new species described or recognized.
Mniarogekko jalu sp. nov. is considered Endangered, but is locally abundant. Correlophus belepensis sp. nov. is
considered Critically Endangered and is restricted to the ultramafic plateaux of Île Art. Although described from the Île
des Pins, we have only been able to confirm the existence of Rhacodactylus trachycephalus on the tiny satellite island Îlot
Môrô and consider it to be Critically Endangered. If indeed restricted to this islet, R. trachycephalus may well have the
smallest range and perhaps the smallest population of any gecko in the world.
www.mapress.com/zootaxa/2012/f/z03404p052f.pdf
