Systematic revision of the marbled velvet geckos (Oedura marmorata species complex, Diplodactylidae) from the Australian arid and semi-arid zones

Abstract

Lizards restricted to rocky habitats often comprise numerous deeply divergent lineages, reflecting the disjunct nature of their preferred habitat and the capacity of rocky habitats to function as evolutionary refugia. Here we review the systematics and diversity of the predominantly saxicoline Australian marbled velvet geckos (genus Oedura) in the Australian arid and semi-arid zones using newly-gathered morphological data and previously published genetic data. Earlier work showed that four largely allopatric and genetically divergent lineages are present: Western (Pilbara and Gascoyne regions), Gulf (west and south of the Gulf of Carpentaria), Central (central ranges) and Eastern (Cooper and Darling Basins). None of these four populations are conspecific with true O. marmorata, a seperate species complex that is restricted to the Top End region of the Northern Territory. Top End forms share a short, bulbous tail whereas the other four lineages treated here possess a long, tapering tail. Morphological differences among the arid and semi-arid lineages include smaller body size, tapering lamellae and a shorter tail for the Gulf population, and a partially divided rostral scale in the Western population compared to the Central and Eastern populations. Accordingly, we resurrect O. cincta de Vis from synonymy for the Central and Eastern lineages, and regard this species as being comprised of two evolutionary significant units. We also describe the Gulf and Western lineages as new species: Oedura bella sp. nov. and O. fimbria sp. nov., respectively. We note that a predominantly arboreal lineage (the Eastern lineage of O. cincta) is more widely distributed than the other lineages and is phylogenetically nested within a saxicoline clade, but tends to have a deeper head and shorter limbs, consistent with morphological variation observed in other lizard radiations including both saxicoline and arboreal taxa.

Young relicts and old relicts: a novel palaeoendemic vertebrate from the Australian Central Uplands

“…The synonymy of the Oedura marmorata complex has recently been considered elsewhere [22]. Two names have been applied to populations from the Central Uplands, but are not applicable to new taxon.…”

“…Measurement protocols and acronyms (see electronic supplementary material) largely follow those outlined elsewhere [22,32]. …”

“…Currently only one taxon ( Oedura cincta ), relatively closely related (estimated Pliocene divergences) to populations of Oedura occurring elsewhere in the eastern AAZ, is recognized [22]. However, a morphologically distinctive population of Oedura from the southern portion of the MRB has been noted since the 1970s [23].…”

Extinct, obscure or imaginary: The lizard species with the smallest ranges

“…It may also reflect the propensity of geckos to have narrow ranges, tropical distribution and nocturnal behaviour (Gamble, Greenbaum, Jackman, & Bauer, ; Meiri, ; Vidan et al., ). Indeed, the propensity of geckos to specialize in using specific and naturally isolated substrates (usually rocks; e.g., Giri, Bauer, Vyas, & Patil, ; Grismer, ; Heinicke, Jackman, & Bauer, ; Oliver, Bourke, Pratt, Doughty, & Moritz, ; Oliver & Doughty, ; Pauwels & Sumontha, ; Wood et al., ) and speciate where these are found may often predispose them to have very small ranges. Large, relatively continuous patches of habitat, such as Amazonia and the Sahara, on the other hand, harbour many lizard species (Roll et al., ), but relatively few TL‐species (Figure ).…”

Tempo and mode of performance evolution across multiple independent origins of adhesive toe pads in lizards

“…We also had performance observations from the recently described Oedura bella, substituting it for the closely related O. gemmata (Oliver et al 2012;Oliver and Doughty 2016). In a few cases we replaced closely related unsampled taxa with taxa for which we had performance measurements.…”