Dixonius dulayaphitakorum SUMONTHA & PAUWELS, 2020
Can you confirm these amateur observations of Dixonius dulayaphitakorum?
|Higher Taxa||Gekkonidae, Gekkota, Sauria, Squamata (lizards: geckos)|
|Common Names||Thai: Djing-djok din Ranong|
E: Ranong leaf-toed gecko
F: Dixonius de Ranong
|Synonym||Dixonius dulayaphitakorum SUMONTHA & PAUWELS 2020|
Type locality: garden of the Ranong Marine fisheries Research and Development Station, Ban Ring Subdistrict, Ranong city, Muang District, Ranong Province, peninsular Thailand
|Types||Holotype. AUP 02002 (field nr MS 626); adult male collected by Montri Sumontha on 20 february 2015.|
Paratypes. (4) PSUZC-R 729 (field no. MS 621) and PSUZC-R 730 (field no. MS 622), adult males. AUP- 02003 (field no. MS 623) and PSUZC-R 731 (field no. MS 706), adult females. All paratypes with the same locality, collector and collecting date as the holotype, except PSUZC-R 731 (field no. MS 706), collected at the same site but in December 2016.
|Diagnosis||Diagnosis. Dixonius dulayaphitakorum sp. nov. can be distinguished from all other congeneric species by its maximal known SVL of 47.8 mm, 22 longitudinal rows of dorsal tubercles; 33 to 35 paravertebral scales; 22 longitudinal rows of ventrals across the abdomen; six or seven precloacal pores in males, no pores in females; no distinct canthal stripe; and a spotted dorsal pattern.|
Coloration in life. Dorsal surface of head brown with poorly contrasting, irregular dark brown spots. No distinct canthal stripe. The supralabials are white with each a brown spot. The background color of the neck and dorsum is brown, with irregular dark brown spots, similarly to the head, and two regularly disposed whitish tubercles on each side. Each flank shows four regularly aligned whitish tubercles, pursuing the series on the neck. The upper part of the tail shows the same background color as the dorsum and head, with irregular brown marks, and eight regularly arranged, poorly defined, whitish bands, the tail ending with a whitish tail tip. The upper surface of the legs is light brown with irregular small dark brown spots. Ventral surfaces of head, body, members and tail whitish, with gray palms and soles. In preservative the colors strongly fade and become less contrasted (figure 2).
Variation. In addition to the type-series, two adult individuals, including a gravid female, were measured but not preserved. Main morphometric and meristic characters of the type-series and these two specimens are provided in Table 1. Morphology and coloration characters of the paratypes and additional specimens agree in most respects with the holotype. The ratio TaiL/SVL among four males (all with an original tail) varies between 1.17 and 1.23; in the only female paratype with an original tail the ratio is 1.12, indicating that females might have a relatively shorter tail. There are four of five regularly aligned pairs of white tubercles on dorsum between limb insertions. The dorsal pattern does not seem to be sexually dimorphic (figures 1, 3–4). Hatchling individuals have chocolate brown dorsal surfaces, with four or five beige tubercles on each flank, and beige, regularly arranged, interrupted rings on tail (figure 4B).
Comparison to other species. Dixonius dulayaphitakorum sp. nov. is distinguished from D. aaronbaueri from southeastern Vietnam based on its larger size (SVL 47.8 vs. 38.6 mm), higher Ven number (22 vs. 18–19), much higher DTR number (22 vs. 11), much lower PV number (33–35 vs. 45–50), lower PV’ number (20–25 vs. 29–32), higher PrePo number (6 or 7 vs. 5), poorly marked canthal stripe, and dorsal pattern (Sp vs. U). It can be differentiated from the western Thai Dixonius hangseesom by its much higher DTR number (22 vs. 12–14), lower IL number (6 or 7 vs. 8), poorly marked canthal stripe, and dorsal pattern (Sp vs. Ba or Bl). It differs from the Thai peninsular endemic Dixonius kaweesaki by its larger size (SVL 47.8 vs. 41.6 mm), lower Ven number (22 vs. 24), much higher DTR number (22 vs. 13 or 14), higher InterOrb number (9 or 10 vs. 6 or 7), lower SL number (8 vs. 10 or 11), lower SLMOrb (6 vs. 7 or 8), lower PrePo number (6 or 7 vs. 9–11), its poorly marked canthal stripe, and its dorsal pattern (Sp vs. St). from Dixonius lao it differs by its smaller size (SVL 47.8 vs. 55.4 mm), lower Ven number (22 vs. 23 or 24), lower PV number (33–35 vs. 40–43), lower SLMOrb (6 vs. 7 or 8), lower PrePo number (6 or 7 vs. 8), and dorsal pattern (Sp vs. U). It can be distinguished from the central Thai Dixonius melanostictus by its much higher DTR (22 vs. 10 or 11), lower SL number (8 vs. 9), lower SLMOrb number (6 vs. 7), lower PrePo number (6 or 7 vs. 9), poorly marked canthal stripe, and dorsal pattern (Sp vs. St). from the southern Vietnamese Dixonius minhlei it can be separated based on its much higher DTR number (22 vs. 14 or 15), lower PV number (33–35 vs. 38–44), and poorly marked canthal stripe. from the Thai peninsular endemic Dixonius pawangkhananti, it differs by its much higher Ven number (22 vs. 16), much higher DTR number (22 vs. 16), higher PV number (33–35 vs. 30–32), higher InterOrb number (9–10 vs. 7), poorly marked canthal stripe, and dorsal pattern (Sp vs. Ba or Bl).
It can be separated from Dixonius siamensis by its much smaller size (SVL 47.8 vs. 57 mm) and its much higher DTR number (22 vs. 10–14). Phyllodactylus burmanicus Annandale, 1905, currently regarded as a subjective junior synonym of D. siamensis, has its type-locality in Tavoy, i.e., in what is now known as Dawei, in southern Myanmar, at about 450 km north of Ranong. It differs from Dixonius dulayaphitakorum sp. nov. by its smaller size (SVL 35 vs. 47.8 mm), lower SL number (6 vs. 8), lower SubLT4 number (8 or 9 vs. 12–15) and the male dorsal pattern (Sp vs. Ba). from the southern Vietnamese Dixonius taoi, Dixonius dulayaphitakorum sp. nov. can be distinguished by its much higher DTR number (22 vs. 11 or 12), weakly marked canthal stripe, and dorsal pattern (Sp vs. Bl). And from Dixonius vietnamensis it differs by its higher Ven number (22 vs. 15–21), higher DTR number (22 vs. 13–17), lower PV number (33–35 vs. 36), higher SL number (8 vs. 7), and poorly marked canthal stripe.
Sympatry: Calotes versicolor, Draco maculatus, D. taeniopterus, Gekko gecko, Gehyra mutilata, Hemidactylus frenatus, H. platyurus and H. murrayi, Hemiphyllodactylus typus, Eutropis multifasciata, Lygosoma bowringii, Sphenomorphus maculatus, Chrysopelea ornata, C. paradisi , Coelognathus radiatus, Gonyosoma oxycephalum, Ptyas korros, Cylindrophis cf. ruffus, Naja kaouthia Lesson, Homalopsis semizonata, Rhabdophis subminiatus, Xenochrophis trianguligerus, Indotyphlops braminus, Xenopeltis unicolor.
|Etymology||Named after Mr. Santisak and Mrs. Boonneam Dulayaphitak, friends of the first author, for their support to his herpetological field work.|