Diplodactylus Gray, 1832

Hutchinson, Mark N., Doughty, Paul & Oliver, Paul M., 2009, Taxonomic revision of the stone geckos (Squamata: Diplodactylidae: Diplodactylus) of southern Australia, Zootaxa 2167, pp. 25-46 : 28-29

Diplodactylus Gray, 1832

Type species: D. vittatus Gray, 1832 , by monotypy.

Diagnosis. A genus of the Diplodactylidae ( Han et al. 2004) distinguished from all but Lucasium and Rhynchoedura by having both lateral and medial pairs of cloacal bones present. Distinguished from Lucasium and Rhynchoedura by the anteriorly enlarged jugal bone that enters the floor of the lacrimal foramen, by having relatively high numbers of preanal spinose scales (generally> 5), absence of preanal pores and shorter, stouter proportions of the body and tail; fourth toe on hind foot approximately four times as long as wide, tail generally swollen and less than 80% of SVL ( Oliver et al. 2007b).

The D. vittatus species complex. Oliver et al. (2007a) referred to lizards described below as the D. vittatus species complex, and the data presented there and in Oliver et al. (2007b) show that they form a paraphyletic assemblage within Diplodactylus . They share a general similarity in habitus and colour pattern, sufficiently similar that all were formerly combined as a single species, D. vittatus, sensu Kluge (1967) . The head and body are moderately stout in general proportions, limbs are of moderate length and build, the tail shows little taper until near the tip and frequently has its maximum diameter at about the midpoint, producing a spindle-shape. The undersides of the digits typically have a single series of enlarged, hemispherical subdigital ‘lamellae’ which tend to break up into smaller scales towards the base of the toes. The labial scales are differentiated from adjacent scales and the nostril is generally surrounded by the rostral, two supranasals, two or three small postnasals, and the first supralabial. There are no tubercular or spinose caudal scales.

The species are coloured in shades of grey, brown or reddish-brown and black, with a dorsal pattern that includes a pale vertebral stripe usually scalloped to produce a zigzag shape, but which may be straight-edged, or broken into a series of angular or irregular dorsal blotches. The vertebral stripe may fork on the neck with a process extending to each eye, or may broaden to form a pale cap over the nape and dorsal surface of the occipital and parietal areas. The edges of the vertebral stripe are weakly to boldly edged with blackish paravertebral margins, the colour fading laterally to a medium shade of grey or brown. The light dorsal stripe continues on to the tail when original, but is often less continuous on the tail than on the body. Colouring of the flanks can be divided into an upper lateral zone of a medium to dark shade of the basic body colouring, and a lower lateral zone that is an extension of the ventral colouring. The upper lateral zone may be immaculate, with or without a peppering of paler and darker scales, or may have a few to many small to large circular spots. Limbs are coloured and patterned similarly to the body. The venter is unmarked light grey to white.

The only member of the complex to depart from this general scheme is D. polyophthalmus , which has an indistinct pale vertebral zone and numerous small, blurry pale dorsal spots. The tendency of all of the markings of D. polyophthalmus to ‘bleed’ into the surrounding colour distinguishes it from all other members of the complex.

The similar species section is based on areas of sympatry and parapatry, and is designed to draw attention to distinguishing features of species that might be found together. As most species show extensive overlap in morphology, this focuses attention on to those characters that are most useful for particular combinations of species.