Diploderma panlong Wang, Che, Siler, 2020

Dong, Wenjie, Li, Ling, Xun, Hao, Gao, Wei, Wang, Kai & Che, Jing, 2024, Extended Descriptions and Revised Diagnoses of Three Recently Described, Little-Known Mountain Dragons (Reptilia: Agamidae: Diploderma) from the Yalong River Valley in Southwest China, Zootaxa 5463 (4), pp. 479-500 : 486-488

Diploderma panlong Wang, Che, Siler, 2020

Newly collected materials. KIZ 039795 , 039796 , adult females, from Yandai town , Jiulong County, Ganzi Zangzu Autonomous Prefecture, Sichuan Province, China, collected in May 2022 .

Revised diagnosis. By measurement of specimens of supplemented females, D. panlong can be diagnosed from congeners by a combination of following morphological characters (1) body size moderate, SVL 60.2–71.7 in males, 63.7–75.8 in females; (2) tail long, TAL 248.2%–268.0% SVL in males, 221.8%–226.8% in females; (3) hind limbs moderate, HLL 77.7%–83.2% SVL in males, 68%–74.8% in females; (4) head moderate, HW 63.4%–67.3% HL in males, 66.5%–71.5% in females; (5) MD 39–46 in males, 37–40 in females; (6) F4S 18–24 in males, 19 or 20 in females; (7) T4S 22–27 in males, 24–26 in females; (8) conical, post-rictal scales strongly developed, 9–13, 1or 2 in females; (9) tympana mostly exposed in males, but hidden in females; (10) nuchal crest moderately developed in males, length of tallest nuchal crest (TNC) 5.4%–7.7% HL in males, 5.4%–5.8% in females; (11) transverse gular fold present in life, shallow, sometimes indistinct after preservation; (12) ventral head and body scales homogeneous, distinctively keeled; (13) gular spots absent in both sexes; (14) dorsolateral stripes smooth-edged, narrow, Sulphur Yellow (Color 80) in males, moderately jagged-edged, irregular blend of Spectrum Yellow (Color 79) and Olive Yellow (Color 117) in females; (15) distinct radial stripes present around eyes except suborbital regions; (16) distinct white lip stripe present on each side below eye in both sexes; (17) gradual transition from Tawny (Color 60) or Amber (Color 51) dorsolateral body coloration to Light Flesh (Color 250) coloration of ventrolateral body surface and eventually to Light Buff (Color 2) coloration of ventral body surface in males, the background color transitions gradually from Olive Yellow (Color 117) to a light gray from the longitudinal stripes on the sides of the body towards the abdomen, and the dorsal sides feature transverse, worm-like black markings in females; and (18) oral cavity Dark Spectrum Yellow (Color 78), tongue Light Chrome Orange (Color 76) in both sexes.

Expanded comparison. D. panlong is phylogenetically sister to D. swild , but it differs from D. swild by having a relatively longer tail (TAL 248.2%–268.0% SVL and 221.8%–226.8% in males and females, respectively vs. 224.4%–239% and 200.4%–221% in males and females, respectively), shorter nuchal crests (TNC 5.4%–7.7% HL and 5.4%–5.8% in males and females, respectively vs. 12.0%–12.4% and 8.1%–11.8% in males and females, respectively), unstable exposure of tympana (mostly exposed in males but hidden in females vs. exposed in both sexes).

For other congeners that are closely aligned with D. panlong , it can be distinguished from D. dymondi by having a different coloration of the oval cavity (Light Chrome Orange [Color 76] vs. Spectrum Violet [Color 186] to Jet Black [Color 300]) and tongue (Light Chrome Orange [Color 76] vs. Pale Pinkish Buff [Color 3]) in both genders. In addition, D. panlong differs from the species D. jiulongense , which has overlapping geographic distribution with D. panlong , by the presence of a gular spot (absent vs. Sulphur Yellow [Color 80]), oval cavity coloration (Light Chrome Orange [Color 76] vs. Pinkish White [Color 216]), and tongue coloration (Light Chrome Orange [Color 76] vs. Light Flesh Color [Color 250]).

Sexual dimorphism and dichromatism. Females are similar in size to males, but differs from males by having a different body shape (compressed dorsally vs. not compressed dorsally), a relatively shorter tail (TAL 221.8%– 226.8% SVL vs. 248.2%–268.0%), relatively shorter limbs (FLL 42%–43.7% SVL, HLL 68%–74.8% SVL vs. 44.9%–46.9%, 77.7%–83.2%), relatively wider and dorsally compressed head (HD 75.9%–76.5% HW vs. 77.8%– 79.5%).

Sexual dichromatism is very conspicuous. In females, the dorsal area between dorsolateral stripes is Pale Neutral Gray (Color 296), with evenly distributed, triangular or heart-shaped, Dark Brownish Olive (Color 127) patches. Dorsolateral stripes are unevenly colored: the medial regions of the stripes are Spectrum Yellow (Color 79) or Olive Yellow (Color 117), while the two ends are Pale Buff (Color 1). Additionally, the dorsolateral stripes are jagged. The background color of the body and limbs is Olive Yellow (Color 117), featuring irregular reticulated Dark Brownish Olive (Color 127) markings on the lateral side. In contrast, in males of D. panlong , area between dorsolateral stripes is near uniformly Clay Color (Color 18) to Brussels Brown (color 33) without Sepia (Color 286) to Jet Black (color 300), and the dorsal surface of limbs are Pale Pinkish Buff (Color 286).

Natural history. The two female specimens ( KIZ 039795 , KIZ 039796 ) were both gravid when collected in May, with five and ten eggs in their abdomens when dissected, respectively. The species was frequently encountered at forest margins, where individuals were observed basking on concrete platforms or rocks near shrubs during the day. Females are more frequently observed on overcast days. At night, individuals rest on shrub branches, about 1–2 meters above the ground .

Female specimens were collected from Yandai Town, Jiulong County, Sichuan Province, where also inhabited by D. jiulongense . The area may mark the upper limit of D. panlong 's distribution along the Yalong River, as the species was not encountered in surveys further upstream, being successively replaced by D. jiulongense and D. daochengense .