Diploderma formosgulae, Wang & Gao & Wu & Dong & Feng & Shen & Jin & Shi & Qi & Siler & Che, 2021

Wang, Kai, Gao, Wei, Wu, Jiawei, Dong, Wenjie, Feng, Xiaogang, Shen, Wenjing, Jin, Jieqiong, Shi, Xiudong, Qi, Yin, Siler, Cameron D. & Che, Jing, 2021, Two New Species of Diploderma Hallowell, 1861 (Reptilia: Squamata: Agamidae) from the Hengduan Mountain Region in China and Rediscovery of D. brevicaudum (Manthey, Wolfgang, Hou, Wang, 2012), Zootaxa 4941 (1), pp. 1-32 : 19-26

Diploderma formosgulae sp. nov. Wang, Gao, Wu, Dong, Shi, Qi, Siler, Che

( Figs. 3 , 6 , 8–10 ; Table 4)

LSID urn:lsid:zoobank.org:act:82CF4E0B-91B6-426B-9F4C-1008BE514F06

Chresonyms. Japalura flaviceps Zhao & Yang 1997:165–167 ; Zhao et al. 1999:111–115; Yang & Rao 2008:200.

Holotype. KIZ 044425, adult male, from Yangla Village , Deqin County, Yunnan Province, China (99.1113˚ E, 28.8905˚ N, elevation 2355m, WGS 84). Collected by Kai Wang , Zhuoyu Lu , Man Fu , and Xiankun Huang on 17 June 2019.

Paratypes. KIZ 044373, 044417, adult males; KIZ 044418, subadult male; KIZ 044424, 044427, 044428, 044435, juvenile males; KIZ 044375, 044420, 044421, 044423, adult females; KIZ 044429, 044430, 044437, juvenile females. All share the same collection information as the holotype.

Etymology. The Latin species epithet formosgulae means “beautiful gular”, which describe the vibrant and diagnostic gular spots of the species. We suggest Vibrant-gulared Mountain Dragon as its English common name, and LJṘAEẘ (Pinyin: Li Hou Long Xi) as its Chinese common name.

Diagnosis. The new species can be diagnosed based on a combination of the following morphological characters: 1) body size moderate, SVL 55.5–60.9 mm in males, 55.9–60.2mm in females; 2) tail long, TAL 195.8–223.5% SVL in males, 186.1–194.8% in females; 3) HW 66.2–75.4% HL; 4) HLL 73.0–80.3% SVL; 5) nuchal and dorsal crests developed on moderate skin folds in males; 6) MD 37–48; 7) F4S 13–16; 8) T4S 18–24; 9) PTS 2–4; 10) PTY 3–6; 11) PRS 4–8; 12) subocular regions and chin pale Pink [Color 242] in most individuals; 13) dorsolateral stripes jagged and Cream Color [Color 12] in males, narrow and Sulphur Yellow [Color 80] or indistinct in females; 14) ventral body uniform Pale Pinkish Buff [Color 3] to Pale Sulfur Yellow [Color 92]; 15) gular spots always present in males, Pinkish Flesh Color [Color 253] to Lilac [Color 222], either as Sulphur Yellow [Color 80] gular spots or Sulphur Yellow [Color 80] reticulated stripes in females.

Comparisons. The new species has been confused with D. flaviceps , but it can be differentiated by the latter by having a smaller body size in males (SVL 55.5–60.9 mm vs. 68.5–82.1mm) and by the presence of distinct radial stripes around eyes (vs. absence), absence of skin folds under nuchal crests in females (vs. presence), absence of lateral series of dark rhomboid patterns between dorsolateral stripes (vs. presence), and by the presence of colorful gular spots or gular patterns in both sexes (vs. absence).

For species that are phylogenetically closely related but allopatric ( D. drukdaypo and D. vela ), D. formosgulae sp. nov. can be differentiated from the latter two by the presence of colorful gular spots in both sexes (vs. absence in both D. drukdaypo and D. vela ). In addition, the new species differ from D. drukdaypo by having distinctively keeled ventral scales of head and body (vs. smooth or feebly keeled) and a much longer tail (TAL 195.8–223.5% SVL in males, 186.1–194.8% in females vs. 153.0–154.4% in males, 132.8–144.0% in females; Fig. 6 ); and from D. vela by the absence of strongly developed, continuous sail under the vertebral crests in males (vs. presence).

For all remaining recognized species, D. formosgulae sp. nov. can be differentiated from all species within the HMR (except D. grahami and D. panchi ) by having distinct coloration of gular spots in life (Pinkish Flesh Color [Color 253] to Lilac [Color 222] in males, Sulphur Yellow [Color 80] gular spots or reticulated patterns in females vs. Pale Cyan [Color 157] to Light Caribbean Blue [Color 163] in both sexes of D. aorun ; Spectrum Yellow [Color 79] to Dark Spectrum Yellow [Color 78] in D. angustelinea ; Light Cyan [Color 157] in both sexes of D. batangense ; Light Chrome Orange [Color 76] in males, Dark Spectrum Yellow [Color 78] in females of D. bowoense sp. nov.; Pale Sulphur Yellow [Color 92] in males, no gular spots in females of D. brevicaudum ; Pale Emerald Green [Color 141] to Light Turquoise Green [Color 146] in both sexes of D. flavilabre ; Caribbean Blue [Color 168] in males, Medium Greenish Yellow [Color 88] in females of D. iadinum ; Light Chrome Orange [Color 76] in both sexes of D. laeviventre ; no gular spots in D. panlong , D. slowinskii and D. swild ; Light Sulphur Yellow [Color 93] in both sexes of D. qilin ; Chartreuse [Color 89] or Opaline Green [Color 106] in both sexes of D. yulongense ; and Chartreuse [Color 89] in males, no gular spots in females of D. zhaoermii ).

In addition to distinct gular coloration, D. formosgulae sp. nov. differs from D. angustelinea by having a shorter tail (TAL 195.8–223.5% SVL in males, 186.1–194.8% in females vs. 230.2–249.1% in males, 194.30–222.3% in females; Fig. 6 ) and more developed nuchal and dorsal crests in males (vs. feeble); from D. aorun by a distinct coloration of subocular region and chin (pale Pink [Color 242] vs. white); from D. batangense by having a better developed and more conical scales post rictus (PRS 4–9 vs. 0–3); from D. bowoense sp. nov. and D. brevicaudum by having a tendency toward longer tail in males, much longer in females (TAL 195.8–223.5% SVL in males, 186.1– 194.8% in females vs. 189.1–201.9% in males, 177.3–178.7% in females for D. bowoense sp. nov.; 140–184.1% in males, 125.0–159.1% in females of D. brevicaudum ; Fig. 6 ); from D. iadinum by having less robust head (HD 66.9–73.4% HW vs. 74.0–79.9%) and distinct body coloration (Light Buff [Color 2] to Pale Pinkish Buff [Color 3] vs. Yellowish Spectrum Green [Color 128] to Emerald Green [Color 143] in males, Buff [Color 5] to [Pale Greenish Yellow [Color 86] in females); from D. laeviventre by having distinctively keeled ventral scales of head and body (vs. smooth or feebly keeled); from D. slowinskii and D. swild by having concealed tympanum (vs. exposed); from D. yulongense by the absence of green patches on ventrolateral body of males (vs. presence) and by having more conical scales post rictus (PRS 4–9 vs. 1–4); from D. zhaoermii by having a smaller body size (SVL 55.5–60.9 mm in males, 55.9–60.2mm in females vs. 63.24–81.7mm in males, 61.0– 75.2mm in females) and less and scattered dark radial stripes around eyes (vs. more and densely positioned).

For D. grahami , which does not have coloration data in life, the new species differ from it by having no granular scales (vs. presence) and by having a distinct transverse gular fold (vs. absence). For D. panchi that has similar gular patterns in females, D. formosgulae sp. nov. differs from D. panchi by having a much longer tail (TAL 186.1–194.8% in females vs. 141.8–151.5%).

For the remaining species, D. formosgulae sp. nov. differs from D. chapaense , D. fasciatum , D. menghaiense , D. micangshanense , D. varcoae , D. yunnanense , and all species from East Asian islands ( D. brevipes , D. luei , D. makii , D. polygonatum , and D. swinhonis ) by the presence of a deep transverse gular fold (vs. absence); from D. dymondi by having concealed tympana (vs. exposed); from D. hamptoni by having parallel dorsolateral stripes in males (vs. diagonally oriented) and by having a much deeper transverse gular fold (vs. feeble).

Description of holotype. Body not dorsally compressed, SVL 60.85 mm; tail long, TAL 195.8% SVL; limbs length moderate, FLL 44.8% SVL, HLL 73.0% SVL; head moderate, HW 72.1% HL, HD 72.6% HW; SEL 38.7% HL. Rostral rectangular, twice wider than height, two scales away from nasal; nasal oval, single scale away from first supralabial; supralabials 10/10, weakly keeled, more distinct on last six; infralabials 11/11, feebly keeled, less distinct than supralabials; suborbital scale rows 3/3, each scale bearing distinct, lateral keel; supraciliaries 7/7, overlapping one half of total length with succeeding ones; enlarged, protruding scales between posterior orbit and tympanum, 6/6, each bearing single distinct, lateral keel; tympanum concealed under fine scales; post tympanic conical scales 6/5, well developed and enlarged, two of which much taller than others on each side; enlarged postrictal scales 4/4, sub-pyramidal in shape. Dorsal head scales heterogeneous in size and shape, all distinctively keeled; single, laterally oriented, Y-shaped ridge present on dorsal snout, starting three scales posterior of rostral to posterior end of orbit; interparietal small, parietal eye distinct; postciliary scale much enlarged, subpyramidal shape, with multiple keels; post occipital conical scales well differentiated, 3/3.

Dorsal body scales distinctively keeled, heterogeneous in size and shape; axillary scales fine; shoulder fold present, distinct, extending posteriorly over axilla; enlarged scales arranged in three dorsolateral rows on each side of dorsum from neck to pelvis, ones close to dorsal midline, and two along dorsolateral stripe; nuchal, dorsal crests well developed on moderate skin folds, crest scales erected, serrated, differentiated from nearby dorsal sales; middorsal scales 43. Scales of dorsal limbs distinctively keeled, distinctively heterogeneous on hind limbs; Finger IV and Toe IV longest, Finger IV subdigital lamellae 14/14, Toe IV subdigital lamellae 18/19.

Ventral head scales mostly homogeneous in size and shape, distinctively keeled except chin shields; mental pentagonal, completely enclosed by first pair of chin shields; chin shields 6/5, smooth, two scale-row away from infralabials. Gular pouch present, well developed in life, indistinct after preservation; distinct transverse gular fold present, deep. Ventral body and limb scales distinctively keeled, more pronounced than those of ventral head, homogeneous in size and shape, mostly regularly arranged.

Coloration. The background coloration of the dorsal and lateral surfaces of the head is pale Light Flesh Color [Color 250] to pale Pink [Color 242]. Three Sepia [Color 286] to Jet Black [Color 300] transverse ornamentation patterns are present on the dorsal surface of the head: the first one is somewhat irregular shaped between the anterior edge of the orbit, the second one is a cross-band between the midpoint of the orbits, and the third one is a X-shaped pattern between the posterior edge of the orbit. All three of these transverse ornamentation patterns extend laterally and enter the orbit on each side of the head; and together with five additional Jet Black [Color 300] streaks or series of speckles on the lateral surface of the head on each side, they form the radial stripe pattern around the eyes. The color of the upper lips and the superior portion of the corner of the mouth are more saturated. Random Sepia [Color 286] to Jet Black [Color 300] short strakes and speckles are also present on the dorsal and lateral surfaces of the head.

The background coloration of the dorsum is Light Buff [Color 2] to Pale Pinkish Buff [Color 3]. A Sepia [Color 286] to Jet Black [Color 300] reticulated ornamentation pattern is present on the lateral surface of the body, inferior to the dorsolateral stripes. A dorsolateral stripe is present on each side of the vertebral crest on the dorsum, running from the neck to the pelvis. This dorsolateral stripe is strongly jagged, with six rhombus-shaped extensions distrib- uted evenly across the stripe from the shoulder to the pelvis. Such extensions connect dorsally with the counterparts from the other side of the body, forming six transverse streaks across the vertebral crest. The rhombus extensions and their connecting parts of the dorsolateral stripes are Light Buff [Color 2], where the remaining parts of the dorsolateral stripes are muddied with Burnt Umber [Color 48] speckles and patches. The dorsal surfaces of the limbs and tail are Light Buff [Color 2], with evenly distributed Sepia [Color 286] to Jet Black [Color 300] transverse bands or streaks running from the proximal to the distal ends. These streaks get much paler as they approach the distal ends of the fingers, toes, and the tip of the tail.

The ventral surface of the head is white, with Jet Black [Color 300] speckles and short streaks, which is formed by singular rows of black scales.A distinct, triangular shaped gular spot is present at the posterior center of the gular, which is Rose Pink [Color 243] on the peripheral area and Lilac [Color 222] in the center. The ventral surface of the body is uneven Sulphur Yellow [Color 80], which is more saturated towards the anterior portion of each individual scale and paler towards the posterior tip. No other ornamentation is present on the ventral surface of the body. The ventral surfaces of the limbs and the tail are uniform white, except the distal portion, which becomes more brownish.

Variation. Detailed morphological variation is summarized in Table 4. Sexual dimorphism is evident despite the small sample size, in which the males possess relatively longer tail, relatively shorter trunk, and taller nuchal crests ( Table 4). Furthermore, similar to most Diploderma congeners, D. formosgulae sp. nov. are sexually dichromatic, where males have different gular coloration than females: for females, the gular spots are less concentrated, and the color is Sulphur Yellow [Color 80]. Among the males, the coloration of gular spot varies from Pinkish Flesh Color [Color 252] in juveniles and subadults (i.e. KIZ 44418, 44424, and 44435) to Rose Pink [Color 243] and Lilac [Color 222] in adults (i.e. KIZ 44425 and 44417).

Natural history and conservation. Diploderma formosgulae sp. nov. inhabits the hot-dry valley along the upper Jinsha River in Deqin County, Yunnan Province, China. Individuals were active during the day, basking on rocks and open ground, but slept on low bushes ( Rumex hastatus ) at night. Currently, it is known only along a short section of the upper Jinsha River valley, with an estimated range of about 50km in linear distance, and about 350 km 2 in area of occupancy. Serious habitat degradation was observed at the type locality, due to both natural causes (i.e. recent flooding from the barrier lake upstream in 2018), as well as anthropogenic causes (i.e. constructions for road repair) ( Fig. 11 C 1 and C 2 ). In comparison with congeners in the lower reaches of the Jinsha River (i.e. D. aorun , and D. qilin ), the population density of D. formosgulae sp. nov. is relatively lower. Currently, the new species’ range overlaps with major roads and townships in the area, and the habitat is not protected by any existing nature reserve. Following the IUCN listing criteria B 2b (iii) (area of occupancy estimated less than 500km 2, observed continuing decline in quality of habitat), we recommend listing the new species as Endangered (EN), and we recommend listing it as Class II protected for Chinese Wildlife Protecting Act, in the hope this will bring protection to its degrading valley habitats.

Figures

FIGURE 1. Distributions of Diploderma species in Southwest China. Numbered shapes represent type localities of Diploderma species: the rectangle represents true D. flaviceps (5), stars represent the two new species described in this study (1: D. bowoense sp. nov.; 2: D. formosgulae sp. nov.), and circles represent type localities of the remaining recognized congeners (1: D. splendidum; 2: D. micangshanense; 3: D. zhaoermii; 4: D. grahami; 6: D. panchi; 7: D. angustelinea; 8: D. panlong; 9: D. swild; 10: D. dymondi; 11: D. varcoae; 12: D. flavilabre; 13: D. batangense; 14: D. aorun; 15: D. qilin; 16: D. brevicaudum; 17: D. yulongense; 18: D. drukdaypo; 19: D. vela; 20: D. iadinum; 21: D. laeviventre; 22: D. slowinskii; 23: D. yunnanense; 24: D. chapaense; and 25: D. menghaiense). The white triangle represents a new locality of D. brevicaudum in Shangjiang Village, Shangri-La County, Yunnan, China.

FIGURE 2. Phylogenetic relationships among members of the genus Diploderma inferred from mitochondrial gene ND2 (1031bp). Bayesian posterior probabilities are mapped onto the topology from Maximum Likelihood analyses.All tip nodes that unify each individual species are well supported (BSŻ90, BPŻ0.98) and hence removed from the tree. “–” indicates unresolved relationships at the node in question in Bayesian analyses. The two new species and D. brevicaudum are shaded with the same color as they appear in the map in Figure 1. The circled number of each species corresponds to those presented in Figure 1.

FIGURE 3. Comparisons of gular coloration in life between (1) males and (2) females of (A) Diploderma bowoense sp. nov., (B) D. formosgulae sp. nov., (C) D. aorun, (D) D. batangense, (E) D. vela, (F) D. angustelinea, (G) D. qilin, and (H) D. brevicaudum. The smaller inset photos in A1 represent gular coloration of the representation of juvenile male of D. formosgulae sp. nov. Photos by Kai Wang.

FIGURE 6. Boxplot showing the important diagnostic morphometric character, relative tail length, of males and females of the two new species (Diploderma bowoense sp. nov. and D. formosgulae sp. nov.) and their closest congeners. Each box represents the interquartile range (25th to 75th percentile), the thick horizontal bar inside each box indicates the median value, the vertical lines indicate maximum and minimum values. Diploderma panchi and D. panlong are known by a single sex only (female and male, respectively), therefore data of only one sex are available.

FIGURE 8. Dorsolateral (1) and ventral (2) views of the male holotype KIZ 044700 (A) and female paratype KIZ 044703 (B) of Diploderma bowoense sp. nov. in preservation. Photos by Zhongbing Yu.

FIGURE 9. Dorsolateral view (1) and closeup of the lateral surface of the head (2) of the male holotype KIZ 044425 (A) and female paratype KIZ 044375 (B) of Diploderma formosgulae sp. nov. in life. Photos by Kai Wang.

FIGURE 10. Dorsolateral (1) and ventral (2) views of the male holotype KIZ 044425 (A) and female paratype KIZ 044375 (B) of Diploderma formosgulae sp. nov. in preservation. Photos by Kai Wang.

FIGURE 11. Habitats at the type localities of (A) Diploderma bowoense sp. nov. and (B) D. formosgulae sp. nov.; and the observed habitat destructions near the type locality of D. formosgulae sp. nov. (C1 and C2). Photos by Kai Wang and Wenjie Dong.