Friday, July 10, 2015

[Herpetology • 2015] The Systematics and Independent Evolution of Cave Ecomorphology in Distantly related Clades of Bent-toed Geckos (Genus Cyrtodactylus Gray, 1827) from the Mekong Delta and Islands in the Gulf of Thailand


Distribution of species with the Cyrtodactylus condorensis and C. intermedius species complexes
FIGURE 2. General differences in body stature between the general scansorial ecomorphs (figures on the upper and lower left) and the cave-dwelling ecomorphs (figures on the upper, middle and lower right).
Upper left: Cyrtodactylus leegrismeri (LSUDPC 8228) from Hon Khoai Island, Ca Mau Province, Vietnam.
Middle left
C. leegrismeri (LSUDPC 9446) from Tho Chu Island, Kien Giang Province, Vietnam. Lower left: C. condorensis (LSUDPC 8202) from Con Dao Island, Con Dao Province, Vietnam. 
Upper right: C. hontreensis (LSUDPC 3062) from Hon Tre Island, Kien Giang Province, Vietnam.
Middle right: C. grismeri (LSUDPC 3162) from Tuc Dup Hill, An Giang Province, Vietnam.
Lower right: C. eisenmani (LSUDPC 8760) from Hon Son Island, Kien Giang Province, Vietnam.
Grismer, Wood, Tri & Murdoch, 2015 || DOI: 10.11646/zootaxa.3980.1.6

FIGURE 3. Hypothesized ancestral-descendant relationships depicting the independent evolution of the cave-dwelling ecomorph from the general scansorial ecomorph.
Grismer, Wood, Tri & Murdoch, 2015

Abstract

An integrative taxonomic analysis of the distantly related Cyrtodactylus condorensis and intermedius species complexes of the Mekong Delta revealed that C. paradoxus is a junior synonym of C. condorensis and that C. thochuensis is a junior synonym of C. leegrismeri. Additionally, the analysis revealed that a cave-dwelling ecomorpholgy has evolved independently early on in the evolution of both complexes (represented by C. hontreensis in the intermedius complex and C. grismeri and C. eisenmani in the condorensis complex) and cave ecomorphs exist in sympatry—but not syntopy—with general scansorial ecomorphs. Multiple, recent, cyclical, glacioeustatic driven changes in sea levels across the Sunda Shelf are hypothesized to account for the evolution and distribution of the widely separated, conspecific insular populations of C. condorensis and C. leegrismeri. The independent evolution of cave ecomorphology is proposed to have been driven by competition avoidance. Habitat islands across the Mekong Delta are an important source of endemism and in need of protection.

Keywords: Reptilia, ecomorphology, Cyrtodactylus, habitat islands, Mekong Delta, Vietnam, systematics

Distribution of species with the Cyrtodactylus condorensis and Cintermedius species complexes
Grismer, Wood, Tri & Murdoch, 2015 || DOI: 10.11646/zootaxa.3980.1.6



Grismer, L. L., P. L. Wood, Jr., Ngo V. Tri and Matthew Murdoch. 2015. The Systematics and Independent Evolution of Cave Ecomorphology in Distantly related Clades of Bent-toed Geckos (Genus Cyrtodactylus Gray, 1827) from the Mekong Delta and Islands in the Gulf of Thailand. Zootaxa, 3980(1): 106–126. DOI: 10.11646/zootaxa.3980.1.6

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