The biogeographic and tectonic history of India

Abstract

Aim To present an up to date account of the Mesozoic history of India and its relationship to the other Gondwana continents and to Eurasia.Location Continents surrounding the Western Indian Ocean.Methods Utilization of recent evidence of continental relationships based upon research in stratigraphy, palaeomagnetism, palaeontology, and contemporary biotas. ResultsThe physical data revealed a sequence of events as India moved northward: (1) India-Madagascar rifted from east Africa 158-160 Ma (million years ago), (2) India-Madagascar from Antarctica c. 130 Ma, (3) India-Seychelles from Madagascar 84-96 Ma, (4) India from Seychelles 65 Ma, (5) India began collision with Eurasia 55-65 Ma and (6) final suturing took place c. 42-55 Ma. However, data from fossil and contemporary faunas indicate that, throughout the late Cretaceous, India maintained exchanges with adjacent lands. There is an absence in the fossil record of peculiar animals and plants that should have evolved, had India undergone an extended period of isolation just before its contact with Eurasia.Main conclusions The depiction of India in late Cretaceous as an isolated continent is in error. Most global palaeomaps, including the most recent one, show India, as it moves northward, following a track far out in the Indian Ocean. But the evidence now indicates that India's journey into northern latitudes cannot have taken place under such isolated circumstances. Although real breaks among the lands were indicated by the physical data, faunal links were maintained by vagile animals that were able to surmount minor marine barriers. India, during its northward journey, remained close to Africa and Madagascar even as it began to contact Eurasia.

Nuclear gene phylogeny of narrow-mouthed toads (Family: Microhylidae) and a discussion of competing hypotheses concerning their biogeographical origins

“…Van Bocxlaer et al (2006) alternatively proposed that land connections among Gondwanan landmasses may have persisted longer, contrary to the traditional paleogeographical reconstructions. In fact, the Kerguelen plateau provided a connection between Madagascar-India and Antarctica (and thereby with Australia and South America) in the Late Cretaceous which led to faunal interchanges (Krause et al, 1999;Noonan and Chippindale, 2006), and the drifting Indian continent may have been simultaneously close to Madagascar, Africa, and Asia (Patriat and SegouWn, 1988;Briggs, 2003). The hypothesis of Van Bocxlaer et al (2006) largely relies on a phylogenetic reconstruction of microhylids, based on a dataset of 2865 nucleotides, which similar to our tree has almost no support for basal relationships among major clades.…”

“…At least for the Natatanura this was most likely Africa since the basal lineages of ranoids and natatanurans are endemic to that continent ( Van der Meijden et al, 2005). After a presumed secondary contact between India and Africa (Briggs, 2003), a subset of these frogs could have dispersed to India, radiated there, and several subgroups then again dispersed to Madagascar (and possibly from there, once more, over the Kerguelen plateau and Antarctica to South America). Hence, the initial phylogenetic splits explaining the current transcontinental distribution of these frogs would have been two or more dispersals (over land or crossing narrow sea straits).…”

Glaciations, gradients, and geography: multiple drivers of diversification of bush frogs in the Western Ghats Escarpment

“…This region has gone through a long period of insularity during its northward drift towards Asia from Africa [26]. There is growing evidence that a number of Gondwana relicts are distributed in the Western Ghats and Sri Lanka [27] with considerable endemism among disparate taxa [25,[28][29][30].…”

Simulating Forest Cover Changes of Bannerghatta National Park Based on a CA-Markov Model: A Remote Sensing Approach

“…India is ranked as a megadiversity country [23,24], experiencing rapid change in demography, economy and society and as such it faces severe conservation challenges [25]. The conservation approach that India has taken since Independence is creating PAs [25], which at present cover 3-4% of the total land area of the country [26].…”