Monday, November 28, 2011

[Herpetology • 2004] Ptyctolaemus collicristatus • Phylogenetic relationships of the genus & new species from the Chin Hills of Western Myanmar

Ptyctolaemus collicristatus Schulte & Vindum, 2004

A new species of Ptyctolaemus is described from the Chin Hills, Chin State, western Myanmar. Specimens were found on the slopes of Mount Victoria between elevations of 709 m and 1,940 m in areas of secondary forest in close proximity to human habitation. The new species differs from P. gularis, by having a more developed nuchal crest, shorter limbs, larger and more heterogeneous dorsal body scales, and a shorter tail. P. phuwuanensis can be distinguished from P. gularis and the new species by the presence of femoral pores and a distinct gular region. A molecular phylogenetic analysis of P. gularis, P. phuwuanensis, the new species of Ptyctolaemus from Chin State, and other species in the draconine clade indicates that P. phuwuanensis is sister to all other draconine agamids, and, in light of these results, we recommend the recognition of the genus name Mantheyus for P. phuwuanensis. Ptyctolaemus from Chin State and P. gularis are related but different genetically and morphologically representing separate species.

FIGURE 5. (A) View of anterior portion of Ptyctolaemus collicristatus, sp. nov., CAS 227489, and (B) P. gularis, CAS 221433. Photographed by Hla Tun and Dong Lin, respectively.

ETYMOLOGY.— The specific epithet is derived from the Latin “collum” meaning neck and “cristatus” meaning crested and refers to the nuchal crest.

NATURAL HISTORY AND DISTRIBUTION.— Ptyctolaemus collicristatus has, thus far, only been found on the slopes of Mt. Victoria, Chin State, Myanmar (Fig. 8). Although thorough surveys in Chin State have not been conducted, recent (July-August, 2003) surveys carried out by the Myanmar Herpetological Survey team in the vicinity of Hakha (northern Chin State) failed to find individuals of either species of Ptyctolaemus. All specimens of P. collicristatus were found in dry mountain forest with deciduous hardwoods and pine between elevations of 790 m and 1,940 m. All specimens were found in areas of secondary forest in close proximity to human habitation. Two specimens were found on trees approximately 2 m above ground, the others were active on the ground.

FIGURE 8. The distribution of Ptyctolaemus collicristatus, sp. nov. (closed squares with the type locality represented by a star) and Ptyctolaemus gularis (closed circles represent specimens examined, open circles represent literature records (Huang 1980; Pawar and Birand 2001). Map prepared by Michelle S. Koo.

FIGURE 1 Phylogenetic relationships among agamid lizards based on maximum parsimony analysis of molecular data (length = 9047 steps). Bootstrap values are presented above branches and decay indices are shown in bold below branches on the phylogram.

Schulte II, J.A., J.V. Vindum, H. Win, T. Thin, K.S. Lwin, and A.K. Shein. 2004. Phylogenetic relationships of the genus Ptyctolaemus (Squamata: Agamidae) with a description of a new species from the Chin Hills of Western Myanmar. Proc. Cal. Acad. Sci., 55(12): 222-247: