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.