Diporiphora margaretae Storr, 1974

MELVILLE, JANE, DATE, KATIE SMITH, HORNER, PAUL & Doughty, Paul, 2019, Taxonomic revision of dragon lizards in the genus Diporiphora (Reptilia: Agamidae) from the Australian monsoonal tropics, Memoirs of Museum Victoria 78, pp. 23-55 : 45-46

Diporiphora margaretae Storr, 1974

Common name. Northwest Kimberley two-lined Dragon.

Figure 18 , Tables 3, 4

Diporiphora bilineata margaretae Storr, G.M. 1974 . Agamid lizards of the genera Caimanops , Physignathus and Diporiphora in Western Australia and Northern Territory. Records of the Western Australian Museum 3: 121–146 [143]. Type data: holotype – WAM R27648, Kalumburu, WA [14° 18' S, 126° 30' E].

Diagnosis. Body size small to moderate (to 55 mm SVL) with long tail (2.5–2.7 × SVL). Gular fold absent, post-auricular fold weak to moderate, scapular fold moderate to strong. Granular scales in axilla, extending over arm onto neck to posterior edge of the scapular fold. Scales on outer rows of dorsolateral stripes have raised trailing edge in some individuals, particularly over shoulder, giving moderate demarcation between dorsal and lateral surfaces. Enlarged pale scales on sides tending to form vertical bars. Pre-cloacal pores 4; femoral pores 0.

Description of holotype. Female; 55 mm SVL; 128 mm tail length. A medium-sized Diporiphora , moderately gracile with long limbs and tail. One canine on either side of upper jaw. Gular, post-auricular and scapular folds absent. Dorsal scales strongly keeled, relatively large and homogenous, although band of smaller homogenous scales across back of head and neck. Longitudinal series of raised, but not enlarged, pale paravertebral and dorsolateral scales at the shoulder, not extending down dorsum. Scales on flanks homogeneous, although changing from small granular scales in axilla to small, non-granular scales on the posterior two-thirds of flanks. A few small pale spinose scales at back of head on each side, lacks spinose scales limbs on tail. Granular scales in axilla, extending over arm onto neck to posterior edge of the scapular fold. Ventral scales strongly keeled. Pre-cloacal pores 4; femoral pores 0.

Dorsum strongly patterned. Six irregular dark brown squares (rather than transverse bands) between head and pelvis either side of a broad grey vertebral stripe, intersected by poorly defined, light brown dorsolateral stripes. Dark brown squares are narrower than the pale background. Head relatively plain with little patterning, labials similar colour to rest of head and lacking pale line between eye and ear. Dark smudge on posterior of tympanum absent. Complex patterning on flanks; granular scales on flanks around arm are dark brown, extending posteriorly onto flanks that have speckled appearance due to seemingly random assortment of scale colours from white, cream, grey, light brown and dark brown; dark dorsal squares also extend as dark patches onto flanks. Lateral stripe between axilla and groin absent. Darker scales in axilla not extending up onto shoulder. Arms with faint dark banding. Banding on legs not well defined, with light bands narrower than dark bands. Dark bands on anterior third of tail, fading to unbanded light colouration for remainder of tail. Ventral surface cream with a few scattered fleck of light brown on ventrum, throat and head.

Variation. 44–55 mm SVL; 110–135 mm tail length. Tail long, ranging from 2.5–2.7 × SVL. Gular fold always absent, post-auricular and scapular vary from weak to moderate. Low nuchal crest present. Spinose scale above tympanum, with 1–4 low spines on post-auricular fold. On dorsolateral row on neck, scales with posterior edges raised. Dorsal scales relatively homogeneous; an exception is the 2nd paravertebral row tending to be slightly enlarged. On flanks, keels of scales angled dorsally and posteriorly; flanks with scattered enlarged scales, tending to align vertically. Pre-cloacal pores 4; femoral pores 0.

Dorsal colour pattern variable. In patterned individuals, cream, grey, light brown to dark brown complex pattern with white dorsolateral stripes. Five or six irregular dark brown bands either side of a broad greyish vertebral stripe 3–5 scales wide. Granular scales on flanks around arm are usually dark brown, extending posteriorly onto flanks. Sides with speckled appearance due to scattered pale scales on enlarged scales on a dark background, often forming vertical rows. The dark bands on the dorsal surface do not extend laterally on the body and in most individuals the bands do not extend beyond the white dorsolateral stripes. In small heavily marked individuals, there is often a dark-edged pale lateral stripe. In plainer individuals, often adult males, dark transverse bands across the dorsum are either absent or faint. Lateral surfaces not as dark and speckled as for patterned individuals. No white markings on face, labial scales speckled with dark brown flecks. Banding on limbs not well defined, with light bands narrower than dark bands. Dark bands on anterior third of tail, fading to unbanded light colouration for remainder of tail. Ventral surface cream sometimes with a few scattered flecks of light brown on gular region and ventrum; occasionally several pairs of lines in gular region.

Distribution and ecology. Restricted to the far north Kimberley region, with records from the Anjo Peninsula and Sir Graham Moore Island in the extreme north, Kalumburu, Mitchell Plateau, Prince Regent River and Drysdale River National Parks, and on Mary Island.

This species has been recorded from Eucalyptus woodland, cane grass, triodia on sandstone and other rocky areas.

Comparison to other species. The distribution of D. margaretae overlaps with a number of other Diporiphora species, including D. albilabris , D. bennettii , D. perplexa sp. nov., D. magna and D. pallida sp. nov. Diporiphora maragetae differs from D. magna in having weak or absent post-auricular and scapular folds (as opposed to consistently strong folds), and having flanks that have a speckled or barred appearance due to scattered pale scales on a dark background. Diporiphora margaretae can be distinguished from D. albilabris , D. bennettii and D. perplexa sp. nov. in lacking a gular fold and femoral pores, and having single canines on either side of the upper jaw. Diporiphora margaretae differs from D. pallida sp. nov. in possessing a more gracile habitus with longer limbs and tail, lacking a gular fold and having granular scales in axilla.

Remarks. This species was originally described as a subspecies on D. bilineata ( Storr, 1974) but was subsumed into D. magna without comment in Storr et al. (1983), despite having the largest difference in body size of any species pair within the D. bilineata species group. Genetic work, across multiple genes ( Smith et al. 2011), demonstrated the distinctiveness of this species relative to D. bilineata and D. magna . Phylogenetic analyses support it being the sister species to D. gracilis sp. nov. (fig. 1c).

Figures

Figure 18. Diporiphora margaretae: a, adult male (NMV D73834), King Edward River, Kimberley, Western Australia (photo:J. Melville); b, holotype WAM R27648, Kalumburu, Western Australia.