Evolutionary biogeography of the centipede genus Ethmostigmus from Peninsular India: testing an ancient vicariance hypothesis for Old World tropical diversity

Abstract

BackgroundUnderstanding the relative influence of vicariance and dispersal in shaping Old World tropical biodiversity remains a challenge. We aimed to infer the roles of these alternative biogeographic processes using a species time-tree for the centipede genus Ethmostigmus from the Old World tropics. Additionally, we explored fine-scale biogeographic patterns for an endemic radiation of Ethmostigmus from the peninsular Indian Plate (PIP), an area with complex geological and climatic history.ResultsDivergence time estimates suggest that Ethmostigmus began diversifying in the Early Cretaceous, 125.4 (± 25) million years ago (Ma), its early biogeographic history shaped by vicariance. Members of Ethmostigmus in PIP form a monophyletic group that underwent endemic radiation in the Late Cretaceous, 100 (± 25) Ma. In contrast, a new species of Ethmostigmus from north-east India formed a clade with African/Australian species. Fine-scale biogeographic analyses in PIP predict that Indian Ethmostigmus had an ancestor in southern-central parts of the Western Ghats. This was followed by four independent dispersal events from the southern-central Western Ghats to the Eastern Ghats, and between different parts of the Western Ghats in the Cenozoic.ConclusionsOur results are consistent with Gondwanan break-up driving the early evolutionary history of the genus Ethmostigmus. Multiple dispersal events coinciding with geo-climatic events throughout the Cenozoic shaped diversification in PIP. Ethmostigmus species in PIP are restricted to wet forests and have retained that niche throughout their diversification.Electronic supplementary materialThe online version of this article (10.1186/s12862-019-1367-6) contains supplementary material, which is available to authorized users.

Granite boulders act as deep‐time climate refugia: A Miocene divergent clade of rupicolous Cnemaspis Strauch, 1887 (Squamata: Gekkonidae) from the Mysore Plateau, India, with descriptions of three new species

“…The group has a Western Ghats origin with two independent dispersals into Sri Lanka and two independent dispersals into the dry zone in the late Oligocene–early Miocene, with a recent dispersal to SE Asia from Sri Lanka. Our lack of sampling from the Western Ghats and especially the southern Western Ghats precludes analyses of the origins of the genus within the Western Ghats—though many ancient lineages in peninsular India have southern Western Ghats origins (e.g., Grismer et al., 2016; Joshi & Edgecombe, 2019; Joshi & Karanth, 2011; Prasad, Farooqui, Tripathi, Garg, & Thakur, 2009).…”

Origin and evolution of the genus Piper in Peninsular India

“…Another study by Biju and Bossuyt (2003) revealed that the frog genus Nasikabatrachus (Sooglossidae), endemic to the Western Ghats, is a Gondwanan relict, thus establishing an older biotic link between the Indian subcontinent with Seychelles to the early Cretaceous. Similarly, a recent study by Joshi and Edgecombe (2019) suggest the evolutionary history of Peninsular Indian centipede Ethmostigmus (Scolopendridae) was shaped by the Gondwanan breakup. Most of the biogeographic studies in the last decade within Peninsular India have focused mainly on faunal components (e.g., Agarwal and Karanth, 2015;Bossyut and Milinkovitch 2001;Datta-Roy et al, 2012;Bansal and Karanth, 2010) whereas the biogeography of floral elements remains relatively under explored.…”

Spatial patterns of phylogenetic diversity and endemism in the Western Ghats, India: a case study using ancient predatory arthropods

“…Among the centipede genera studied here, in India, Digitipes is restricted to the wet forests of the Western Ghats, while Ethmostigmus lineages have dispersed to wet forests in the Eastern Ghats in the past (Joshi & Edgecombe, 2019) and Rhysida is widely distributed across different habitat types throughout peninsular India. Our species distribution models predict ranges of E. tristis, R. konda (both of which are Eastern Ghats endemics) and the more widespread R. trispinosa, which extend into the eastern boundary of the Western Ghats.…”

“…50 Ma. As a result, the WG harbours taxa with both Gondwanan and Asian affinities as well as many endemic radiations (Bossuyt & Milinkovitch, 2001;Gower et al, 2011;Joshi & Edgecombe, 2019;Joshi & Karanth, 2011;Surveswaran et al, 2020). In addition, peninsular India also experienced massive volcanic activity during the Cretaceous (ca.…”