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)

Abstract

Recent studies have highlighted the underestimated diversity of the genus Diploderma Hallowell, 1861 in the Hengduan Mountain Region in Southwest China, but much of the region remains poorly surveyed for reptile diversity. In this study we describe two new species of Diploderma from the upper Jinsha and middle Yalong River Valley, based on evaluations of morphological, genetic, and distribution data. The two new species are morphologically most similar to D. angustelinea and D. vela, but they can be diagnosed from both recognized taxa and all remaining congeners by a suite of morphological features, particularly the distinct coloration of gular spots. Additionally, both new species either render other recognized species paraphyletic or are allopatric with respect to their morphologically similar congeners. Furthermore, we rediscover D. brevicaudum in the wild for the first time, which was known from historical museum specimens only. We estimate the phylogenetic position of D. brevicaudum within the genus Diploderma based on mitochondrial genealogy, and we provide an expanded diagnosis and comparisons against closely related congeners and provide a detailed description of coloration in life based on newly collected specimens. Our discoveries of the new Diploderma species further highlight the urgent conservation needs of the currently neglected hot-dry valley ecosystems in the Hengduan Mountain Region of China.

Four new species of the genus Diploderma Hallowell, 1861 (Squamata, Agamidae) from China

“…Allopatric distribution across the Hengduan Mountain Region have been suggested to create reproductive isolation through geographic isolation ( Wang et al 2015 , 2021a ; Dong et al 2020 ). Wang et al (2021b) considered that D. drukdaypo may represent a recently diverged species from the D. vela lineage, adapted to higher-elevated habitats in the upper Mekong River valley, and suggested that further studies are needed to gain a better understanding of gene flow and speciation mechanisms between these two sister species.…”

“…We compared morphological characters of the new species with other members of the genus relying on examined specimens and original species descriptions ( Hallowell 1861 ; Günther 1864 ; Anderson 1878 ; Boulenger 1906 , 1918 ; Barbour and Dunn 1919 ; Stejneger 1924 ; Mertens 1926 ; Smith 1935 ; Gressitt 1936 ; Bourret 1937 ; Song 1987 ; Ota 1989 ; Ota et al 1998 ; Li et al 2001 ; Gao and Hou 2002 ; Manthey et al 2012 ; Wang et al 2015 , 2016 , 2019b , d , 2021a , b , 2022a ; Ananjeva et al 2017 ; Rao et al 2017 ; Liu et al 2020 , 2022 ; Cai et al 2022 ), and the additional data from Wu et al (2005) , Manthey (2008) , and Wang et al (2017 , 2018 , 2019b , c , 2021a , 2022b ).…”

“…Currently the genus Diploderma Hallowell, 1861 comprises 42 recognized species ( Cai et al 2022 ; Liu et al 2022 ; Wang et al 2022b ) which are mainly distributed in the hot-dry river valleys of the Hengduan Mountain Region of southwestern China, and more than half of them were described in the past decade ( Wang et al 2021a , 2022a ; Cai et al 2022 ; Liu et al 2022 ; Uetz et al 2022 ).…”

Three new species of Diploderma Hallowell, 1861 (Squamata, Agamidae) from the Hengduan Mountain Region, south-western China

“…Therefore, the species inhabiting forests are relatively less threatened by humans. On the contrary, if a section of a river valley is destroyed, such as by expansion of townships and agricultural lands, construction of tourist sites, development of highways and construction of hydroelectric plants (Wang et al 2016(Wang et al , 2019b(Wang et al , 2021a, the endemic species there may become extinct. Therefore, the species inhabiting river valleys are more vulnerable to human threats.…”

“…Diploderma Hallowell, 1861, is a genus including 36 species recognised currently (Uetz et al 2022;Wang et al 2022). Of the total diversity, 34 species are distributed in China, of which 22 species are only distributed in the Hengduan Mountain Region of south-western China (Wang et al 2021a(Wang et al , 2022.…”