Friday, March 25, 2016

[Herpetology • 2014] Independent Transitions between Monsoonal and Arid Biomes Revealed by Systematic Revision of A Complex of Australian Geckos (Diplodactylus; Diplodactylidae)


Fig 7. Species of the Diplodactylus conspicillatus complex in life.
(A) Diplodactylus conspicillatus from 10km north of Barkley Hwy on Ranken to Alexander Station Road, north-eastern Northern Territory (Image: Ross Sadlier); (B) Diplodactylus conspicillatus Alice Springs, Northern Territory (Image: Eric Vanderduys);
(C) D. hillii, Dorat Road, Northern Territory (Image: Paul Horner); (D) Diplodactylus laevis in life from Morgan Range, Western Australia (Image: Mark Hutchinson);
 (E) Diplodactylus platyurus, Brooklyn Station, north Queensland (Image: Eric Vanderduys); (F) Diplodactylus platyurus Myendetta Stn, Charleville, Queensland (Image: Steve Wilson);
(G) Diplodactylus bilybara sp. nov. Onslow, Western Australia (Image: Ryan Ellis); (H) Diplodactylus custos sp. nov. Gibb River Road turnoff via Wyndham, Western Australia (Image: Steve Wilson). There are currently no images available of D. barraganae sp. nov. in life.

Abstract

How the widespread expansion and intensification of aridity through the Neogene has shaped the Austral biota is a major question in Antipodean biogeography. Lineages distributed across wide aridity gradients provide opportunities to examine the timing, frequency, and direction of transitions between arid and mesic regions. Here, we use molecular genetics and morphological data to investigate the systematics and biogeography of a nominal Australian gecko species (Diplodactylus conspicillatus sensu lato) with a wide distribution spanning most of the Australian Arid Zone (AAZ) and Monsoonal Tropics (AMT). Our data support a minimum of seven genetically distinct and morphologically diagnosable taxa; we thus redefine the type species, ressurrect three names from synonymy, and describe three new species. Our inferred phylogeny suggests the history and diversification of lineages in the AAZ and AMT are intimately linked, with evidence of multiple independent interchanges since the late Miocene. However, despite this shared history, related lineages in these two regions also show evidence of broadly contrasting intra-regional responses to aridification; vicarance and speciation in older and increasingly attenuated mesic regions, versus a more dynamic history including independent colonisations and recent range expansions in the younger AAZ.


Diplodactylus barraganae  Couper, P. Oliver & Pepper, 2014
Diplodactylus bilybara  Couper, P. Oliver & Pepper, 2014
Diplodactylus custos  Couper, P. Oliver & Pepper, 2014

Fig 7. Species of the D. conspicillatus complex in life. (A) Diplodactylus conspicillatus from 10km north of Barkley Hwy on Ranken to Alexander Station Road, north-eastern Northern Territory (Image: Ross Sadlier); (B) Diplodactylus conspicillatus Alice Springs, Northern Territory (Image: Eric Vanderduys); (C) D. hillii, Dorat Road, Northern Territory (Image: Paul Horner); (D) Diplodactylus laevis in life from Morgan Range, Western Australia (Image: Mark Hutchinson); (E) Diplodactylus platyurus, Brooklyn Station, north Queensland (Image: Eric Vanderduys); (F) Diplodactylus platyurus Myendetta Stn, Charleville, Queensland (Image: Steve Wilson); (G) Diplodactylus bilybara sp. nov. Onslow, Western Australia (Image: Ryan Ellis); (H) Diplodactylus custos sp. nov. Gibb River Road turnoff via Wyndham, Western Australia (Image: Steve Wilson). There are currently no images available of D. barraganae sp. nov. in life.

Paul M. Oliver, Patrick J. Couper and Mitzy Pepper. 2014. Independent Transitions between Monsoonal and Arid Biomes Revealed by Systematic Revision of A Complex of Australian Geckos (Diplodactylus; Diplodactylidae). PLoS ONE. 10(4): e0126682. DOI:  10.1371/journal.pone.0111895