Strata exposed near Tabbowa Tank, Tabbowa Basin, western Sri Lanka have yielded the

first representatives of the distinctive Permian Glossopteris flora from that country. The assemblage

includes gymnosperm foliage attributable to Glossopteris raniganjensis, roots referable to Vertebraria

australis, seeds assigned to Samaropsis sp., sphenophyte axes (Paracalamites australis) and

foliage (Sphenophyllum emarginatum), and fern foliage (Dichotomopteris lindleyi). This small macroflora

is interpreted to be of probable Lopingian (late Permian) age based on comparisons with the

fossil floras of Peninsula India. Several Glossopteris leaves in the assemblage bear evidence of terrestrial

arthropod interactions including hole feeding, margin feeding, possible lamina skeletonization,

piercing-and-sucking damage and oviposition scarring. The newly identified onshore Permian strata

necessitate re-evaluation of current models explaining the evolution of the adjacent offshore Mannar

Basin. Previously considered to have begun subsiding and accumulating sediment during Jurassic

time, we propose that the Mannar Basin may have initiated as part of a pan-Gondwanan extensional

phase during late Palaeozoic – Triassic time. We interpret the basal, as yet unsampled, seismically

reflective strata of this basin to be probable organic-rich continental strata of Lopingian age, equivalent

to those recorded in the Tabbowa Basin, and similar to the Permian coal-bearing successions

in the rift basins of eastern India and Antarctica. Such continental fossiliferous strata are particularly

significant as potential source rocks for recently identified natural gas resources in the Mannar

Basin.