Diporiphora albilabris 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 : 34-36

Diporiphora albilabris Storr, 1974

Common name. White-lipped two-lined dragon.

Figure 9 , Tables 3, 4

Diporiphora albilabris albilabris 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 [133]. Type data: holotype – WAM R43517, Mitchell Plateau, WA [14° 48' S, 125° 50' E].

Diagnosis. Body size moderate (to 61 mm SVL), tail moderately long (from 1.8–2.5 × SVL). Gular and post-auricular folds present; scapular fold absent. White dorsolateral stripes on raised scale rows. Lacks dark smudge on posterior of tympanum. Scales between dorsolateral stripes are heterogeneous (fig. 10a), with paravertebral row reduced, 2nd paravertebral row enlarged. Pre-cloacal pores 4; femoral pores 2.

Description of holotype. Female. 44 mm SVL, 94 mm tail length. Small body size, moderately robust with long limbs and tail. Two canines on either side of upper jaw. Gular and post-auricular folds present, scapular fold absent. Dorsal scales heterogeneous, with dorsolateral row of enlarged, strongly keeled white scales running from back of head to pelvis and forming well-defined white dorsolateral stripes. Paravertebral rows, either side of the vertebral scale row, are reduced in size compared with adjacent scale rows, leading to the scales of the paravertebral and adjacent scale rows being strongly heterogeneous. To the outer edge of the white dorsolateral stripes, scales are relatively small and keeled, with keels angling toward ventral surface at midbody. Scales on flanks are heterogeneous with scattered slightly enlarged scales. Scales on limbs and tail not spinose, a row of enlarged pale spines on the post-auricular fold. Scales in axilla not granular. Ventral scales strongly keeled. Pre-cloacal pores 3 (2 right; 1 left); femoral pores 2.

Dorsum pattern complex. Wide (~3 scales) poorly defined grey vertebral stipe and prominent white dorsolateral lines from back of head to base of tail. Five wide dark transverse bands between dorsolateral stripes between head and pelvis. Dark bands extend irregularly from the outer side of the white stripes, fading into the colour patterns on the sides. Dark bands are narrower, approximately half the width, than the pale interspaces with background colour. Head strongly patterned: poorly defined line of pale scales from back of eye, over top of ear towards white dorsolateral stripes, although not contacting stripes; labials pale cream, with a few darker flecks, extending as a broad pale band along jaw to back of head and ending at the enlarged spinose scales on the post-auricular fold. Lacks dark spot on posterior of tympanum. Lateral surfaces distinct from dorsum, with sides dark brown with light brown spots, the spots consisting of clusters of 2–4 pale scales on the dark brown scales. Lateral stripe between axilla and groin absent. Lateral dark spot absent Arms weakly banded with dark bands approximately the same width as intervening pale colour. Banding on legs not well defined, dark bands on anterior two-thirds of tail, with dark bands wider than the light bands, fading to unbanded for remainder of tail. Gular region with six grey longitudinal stripes ending at gular fold, ventral surface of torso and tail with cream colouration and unpatterned.

Variation. 43–61 mm SVL; 92–125 mm tail length. Tail long, ranging from 1.8–2.5× SVL. Usually a spine above tympanum, with several spines along post-auricular fold. A short row of spines extends from post-auricular fold to above tympanum, variably expressed with most reaching less than half way to tympanum. Nuchal crest absent to very low in profile. On dorsum, paravertebral row sometimes approaches the size of vertebral row, but is typically reduced in size. The enlarged dorsolateral row decreases in size posteriorly, reaching normal size at the base of the tail.

Dorsal patterning variable and complex with 5–6 dark brown bands from nape to legs between dorsolateral white stripes, intersected by a poorly defined vertebral stripe of grey, approximately 3 scales wide. These dark bands extend irregularly to the outer side of the white stripes, fading into the colour patterns on the sides, which are dark brown with light brown spots. Dorsal patterning tends to be obscured in males in full breeding colouration, where they have strongly contrasting charcoal black, white and chestnut or orange-red colouring on head and upper body, with ventral surface of head, chest and tail also having an orange-red flush in some individuals. Labial scales pale cream with a few darker flecks, extending as a broad pale band along jaw to back of head ending at the enlarged spinose scales on the post-auricular fold. Ventral surface of head often has grey longitudinal stripes ending at gular fold. Ventral surface of body and tail unpatterned and cream in colour.

Distribution and ecology. Restricted to the central and northern Kimberley region (fig. 8). Most records are from the Mitchell Plateau and Prince Regent River National Park, with other records from Kalumburu, Theda and Doongan stations. No specimens known from islands.

A habitat generalist occurring in tropical savannah woodlands and grasslands. Although it occurs in savannah woodlands, it appears to be found in rockier areas within these habitats, including laterite, basalt and sandstone. Observed to perch on rocks or termite mounds.

Comparison with other species. The distribution overlaps a number of other Diporiphora species in the Kimberley. From D. sobria it can be distinguished in lacking a scapular fold and having strongly heterogeneous scales between the pale dorsolateral stripes. It differs from D. perplexa sp. nov. in having heterogeneous dorsal scales, 2 (vs. 0) femoral pores and no dark markings on the tympanum. It differs from D. magna in having a gular fold, femoral pores, double canine teeth in upper jaw and white labial scales. It differs from D. margaretae in having a gular fold and double canine teeth on each side of upper jaw.

Remarks. Originally a nominate subspecies, elevated here to full species (see account above). Although, based on mtDNA, this species is sister to D. bennettii , with which it overlaps in distribution, it is quite different in appearance. Diporiphora albilabris has a more typical Diporiphora appearance of slender body shape and contrasting markings on the dorsum, whereas D. bennettii has a more derived morphology of small body size, short tail length and lack of highly contrasting dorsolateral stripes. Diporiphora albilabris has a relatively small distribution in the northern central Kimberley, yet it is reasonably abundant where it occurs and not under immediate threat, making its conservation status likely to be of least concern.

Figures

Figure 9. Diporiphora albilabris: a, adult male in breeding colouration (registered specimen NMV D73860) from King Edward River crossing, Western Australia (photo: J. Melville); b, dorsal view of holotype WAM R43517, Mitchell Plateau, Western Australia.