Acanthosaura meridiona sp. nov. (Squamata: Agamidae), a new short-horned lizard from southern Thailand

Abstract

A new short – horned lizard species of the genus Acanthosaura from southern Thailand, is described herein. The species was previously recognised as Acanthosaura crucigera and has been reported to present a wide distribution across mainland south-east Asia. The combination of modern morphological studies of Acanthosaura meridiona sp. nov. allows its separation from closely related species A. crucigera, on the basis of presenting more nuchal scales, more scales between diastema, more scales bordering rostral scales and more midline ventral scales. Mitochondrial DNA analysis also indicated a sister relationship between A. meridiona sp. nov. and A. crucigera with a 100 % probability according to Bayesian and maximum – likelihood analyses. The pairwise distance between A. meridiona sp. nov. and A. crucigera ranges from 9.9 – 11.1 %, while the distance between A. meridiona populations ranges from 0 – 0.9 %. This new discovery contributes to the redescription of the distribution of A. crucigera under Kra Isthmus and its replacement by A. meridiona sp. nov.

Phylogeography of mangrove pit vipers (Viperidae, Trimeresurus erythrurus‐purpureomaculatus complex)

“…cf. purpureomaculatus occurs at the Isthmus of Kra (De Bruyn et al, 2005; Hughes et al, 2003; Parnell, 2013), which serves as a biogeographic divide for numerous vertebrate species including reptiles (Grismer et al, 2022; Mulcahy et al, 2017; Olivier S.G. Pauwels et al, 2016; Trivalairat et al, 2022; van Rooijen & Vogel, 2010; Vogel et al, 2012; Zug et al, 2017), amphibians (Buddhachat & Suwannapoom, 2018; Poyarkov et al, 2020; Yodthong et al, 2014), birds (Hughes et al, 2003; Lim et al, 2020), and mammals (Tougard, 2001). Our results also show that phylogeographic structure is latitudinally stratified and consistent with IBD and IBE, with colour polymorphisms appearing to be latitudinally structured as well.…”