Islands as biological substrates: Continental

Abstract

Aim: Describe the main geo-physical features of the various sorts of marine islands that are associated with the continents and consider how the ontogenetic pathways of each landmass type might have shaped the hosted biotas. Location: Global. Methods: Review of the literature that underpins understanding of the “continental” marine islands, particularly those publications with biological, geological, geophysical, oceanographical and palaeoceanographical foci. Results: Based on their geo-physical settings, islands with continental basements/close connections to the continents can be assigned to one of nine categories: shelf, shelf volcano, orogenic margin, continental arc, continental fore-arc, rifted arc-raft, isolated raft atoll, isolated block and micro-continental terrane. As each functions in a distinctive manner, this must have strongly imprinted the native biotas. Main conclusions: “Continental” marine islands can be allocated to one of nine groups based on their respective geo-physical locations. When geological time is considered, then the unique histories of each insular landmass type will have played a critical role in moulding the land-locked faunal assemblages that have amassed and evolved atop them. Researchers investigating insular biotas, particularly those exploring biodiversity growth, may wish to accommodate these insights.