A possible succineid land snail from the Lower Cretaceous non-marine deposits of the Griman Creek Formation at Lightning Ridge, New South Wales

Abstract

A diverse non-marine molluscan fauna has been recorded from the Lower Cretaceous (middle–upper Albian), low-energy, fluvial sediments of the Griman Creek Formation at Lightning Ridge in northern New South Wales. We describe a novel addition to this assemblage—a probable pulmonate gastropod that manifests features (including shell with an inflated body whorl, expansive aperture, and reduced spire/whorl count) consistent with Succineidae, an extant cosmopolitan family of terrestrial snails. The fossils are assigned to a new genus and species (Suratia marilynae), distinguishable from existing taxa by a combination of traits: shell with sculpturing limited to fine growth lines only, lunate body whorl with a rounded periphery, markedly flattened spire (comprising up to two whorls), which is almost flush with the apical surface and delineated by a deeply impressed sutural ‘gutter,’ and presence of both a broad columellar plait and distinct columellar fold. The new taxon apparently constitutes the oldest pulmonate remains recorded from Australasia, and extends the known stratigraphical range of succineids back to the Lower Cretaceous in the Southern Hemisphere.