Upper llandovery (Telychian) graptolites of the oktavites spiralis biozone from the long dai formation, at Lam Thuy village, Quang Binh province, central Vietnam
A numerically small graptolite assemblage from the Long Dai Formation at Lam Thuy village, southwestern Le Thuy district, Quang Binh Province, central Vietnam, includes Oktavites spiralis (Geinitz). The relative abundance of this species in the assemblage, coupled to its occurrence with Oktavites bodentoerlensis Loydell, identifies the lower Silurian (Llandovery Series, Telychian Stage) spiralis graptolite Biozone. Identification of the new locality at Lam Thuy enhances the dataset of Silurian graptolite-bearing localities in central Vietnam and advertises the wide utility of graptolite assemblages for biostratigraphical correlation of lower Palaeozoic strata in northern and central Vietnam.