Thursday, September 20, 2018

[Herpetology • 2018] A Phylogenetic Taxonomy of the Cyrtodactylus peguensis Group (Squamata: Gekkonidae) with Descriptions of Two New Species from Myanmar; Cyrtodactylus meersi & C. myintkyawthurai


Cyrtodactylus meersi  &  C. myintkyawthurai
Grismer​, Wood, Quah, Murdoch, Grismer, Herr, Espinoza, Brown & Lin, 2018


Abstract
A phylogenetic taxonomy of species in the Cyrtodactylus peguensis group from the Ayeyarwady Basin of Myanmar is constructed based on color pattern, morphology, and molecular systematic analyses using the mitochondrial gene NADH dehydrogenase subunit 2. Newly collected samples from the type locality of C. peguensis and other localities indicate that this clade is endemic to central Myanmar and contains at least seven species, four of which are undescribed. Three species, including C. peguensis occur in the low hills of the Bago Yoma Range within the central portion of the Ayeyarwady Basin. Two of these, Cyrtodactylus myintkyawthurai sp. nov. from the northern and central Bago Yoma and Cmeersi sp. nov. which is syntopic with Cpeguensis in the southern Bago Yoma are described herein. As more lowland hilly areas bordering, and within the Ayeyarwady Basin are surveyed, more new species of this group are likely to be discovered. These discoveries continue the recent surge of descriptions of new species of Cyrtodactylus that are being discovered in Myanmar.

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Figure 1: Distribution map of the Cyrtodactylus peguensis group. Distribution of the species of the Cyrtodactylus peguensis group in the Ayeyarwady Basin and the adjacent foothills of the Chin Hills and Shan Hills in Myanmar.


Figure 5: Type specimens and additional specimen of Cyrtodactylus peguensis.
(A) Boulenger’s (1893) illustration of the lost syntype from the type locality of Hpa Lon, Bago Region Myanmar. (B) Syntype BM 946.8.23.10 from the type locality. (C) LSUHC 13454 from the Myin Mo Shwe Taung Pagoda, 9.5 km east of Hpa Lon, Bago Region Myanmar.
Photos by L. Lee Grismer.

Cyrtodactylus peguensis (Boulenger, 1893)
Pegu Bent-toed Gecko
Gymnodactylus peguensis Smith, 1921:29; 1935:52 in part. Wermuth, 1965:63 in part.
Cyrtodactyuls peguensis Taylor, 1963:728 in part; Denzer & Manthey, 1991:314 in part; Cox, Van Dijk & Nabhitabhata, 1998:87 in part; Pianka & Vitt, 2003:175 in part; Manthey & Grossmann, 1997:225 in part; Das, 2010:213 in part; Grismer et al., 2017a:91 in part; Brennan et al., 2017:3, in part.
Cyrtodactylus (Cyrtodactylyspeguensis Rösler, 2000:66 in part.

Syntype. Adult male BM 1946.8.23.10 collected in 1887 by Signor L. Fea from “Palon” (Hpa Lon), “Pegu” (Bago Region), Taikkyi Township, Yangon (north) District, Myanmar. Hpa-Lon is a small village in the Ayeyarwady Basin 9.5 km west of the western foothills of the southern portion of the Bago Yoma Range where Fea reported making zoological collections (Fea, 1897). Being that foothills are the closest suitable habitat for C. peguensis east of Pa-Lon, we restrict the type locality to the Myin Mo Swhe Taung Pagoda, Bago Region, Taikkyi Township, Yangon (north) District, Myanmar (..., elevation 162 m) situated within these foothills where we collected an additional specimen (LSUHC 13454). The other syntype could not be located.

Diagnosis. Cyrtodactylus peguensis differs from other species of the peguensis group by having the unique combination of seven supralabial and infralabial scales; 31 or 32 paravertebral tubercles; 17–19 longitudinal rows of dorsal tubercles; 36 or 37 ventral scales; 19 subdigital lamellae on the fourth toe; 17–19 femoral pores in males; eight precloacal pores in males; three rows of post-precloacal scales; and domed to weakly conical and weakly keeled body tubercles; and a maximum SVL of 70 mm (Table 7).


Figure 7: Holotype of Cyrtodactylus meersi sp. nov. (LSUHC 13455) from the type locality of the Myin Mo Shwe Taung Pagoda, Bago Division, Myanmar.
Photo by L. Lee Grismer.

Cyrtodactylus meersi sp. nov.
Bago Yoma Bent-toed Gecko

Diagnosis. Cyrtodactylus meersi sp. nov. differs from other species of the peguensis group by having the unique combination of seven supralabials and eight infralabials; 32 paravertebral tubercles; 13 longitudinal rows of body tubercles; 32 ventral scales; 17 subdigital lamellae on the fourth toe; 12 femoral pores; eight precloacal pores; two rows of post-precloacal scales; and domed to weakly conical and weakly keeled body tubercles (Table 7). We note, however, that this diagnosis is not robust due to having only a sample size of one juvenile and will be subject to adjustment if additional specimens are ever collected and analyzed. Nonetheless, the placement of this individual near the base of the phylogeny (Fig. 2) and it having an uncorrected percent sequence divergence of 10.0–13.7% from all other species in the phylogeny (Table 3) is strong evidence of its species status.

Distribution. Cyrtodactylus meersi sp. nov. is known only from the type locality of Myin Mo Shwe Taung Pagoda, 9.5 km east of the village of Hpa Lon, Bago Region, Taikkyi Township, Yangon (north) District Myanmar (Fig. 1).

Etymology. The specific epithet, meersi, is named in honor of Mr. John Meers whose generous private donations to Fauna & Flora International’s in the name of karst conservation have resulted in the continuation of karst biology research in Indochina.

Natural History. The holotype was collected in a region composed of low foothills and highly disturbed forest (Fig. 6). The specimen was encountered at 2,000 h as it was sitting in the middle of an ant trail, presumably preying on the ants. The fact that the specimen is a juvenile suggests the reproductive season is prior to May.



Cyrtodactylus myintkyawthurai sp. nov.
Mt. Popa Bent-toed Gecko
Cyrtodactylus fea Wood et al., 2012:995; 
Agarwal et al., 2014:147; Brennan et al., 2017:3.


Figure 8: Type specimens of Cyrtodactylus myintkyawthurai sp. nov. from the type locality of Taung Twin Chaung camp, Mt. Popa, Kyauk-pa-taung Township, Mandalay Region, Myanmar.
 (A) Adult male holotype LSUHC 13808. (B) Adult male paratype LSUHC 13807. (C) Subadult male paratype 13806. (D) Juvenile male paratype LSUHC 13809.
Photos by L. Lee Grismer.

Diagnosis. Cyrtodactylus myintkyawthurai sp. nov. differs from other species in the peguensis group by having the unique combination of six or seven supralabials and six or seven infralabials; 28–33 paravertebral tubercles; 17–23 longitudinal rows of body tubercles; 32–36 ventral scales; 17–19 subdigital lamellae on the fourth toe; 12–20 femoral pores in males; 7–9 precloacal pores in males; two rows of post-precloacal scales; raised, moderately to strongly keeled body tubercles; and a maximum SVL of 75.1 mm.

Distribution. Cmyintkyawthurai sp. nov. ranges throughout Mt. Popa, Mandalay Region and the central section of the Bago Yoma Range, Bago Region (Fig. 2).

Etymology. The specific epithet, myintkyawthurai, is a patronym honoring Myint Kyaw Thura for his contributions to the study of herpetology in Myanmar, his discovery of several new species, and his collaboration with foreign researchers.

Natural History. At both Mt. Popa and in the central Bago Yoma Range, C. myintkyawthurai sp. nov. occurs in hilly regions covered in deciduous dipterocarp forest up to 978 m in elevation (Fig. 9). The Mt. Popa specimens were collected at night from 0.05 to 1 m above the ground on rocks, the trunks of small trees, on leaves or on the ground amongst small rocks.



Conclusions: 
A phylogenetic taxonomy of species in the Cyrtodactylus peguensis species group from the Ayeyarwady Basin of Myanmar recovers at least seven species, four of which are undescribed. Three species, including C. peguensis occur in the low hills of the Bago Yoma mountain range one of which, C. meersi sp. nov., is syntopic with C. peguensis. As more lowland hilly areas associated with the Ayeyarwady Basin are surveyed, more new species of this group are likely to be discovered. These discoveries continue the recent surge of descriptions of new species of Cyrtodactylus that are being discovered in Myanmar.


L. Lee Grismer​, Perry L. Wood Jr, Evan S.H. Quah, Matthew L. Murdoch, Marta S. Grismer, Mark W. Herr, Robert E. Espinoza, Rafe M. Brown and Aung Lin. 2018.  A Phylogenetic Taxonomy of the Cyrtodactylus peguensis Group (Reptilia: Squamata: Gekkonidae) with Descriptions of Two New Species from Myanmar.  PeerJ. 6:e5575. DOI: 10.7717/peerj.5575