Marine influence in the Triassic ‘uplands’

Abstract

Several authors^1–4 have concluded that Mesozoic reptiles found in some fissures of the Bristol area belonged to a distinctive ‘upland’ fauna. We describe here a new fissure deposit recently found in the Carboniferous limestone near Thornbury which contains characteristic ‘upland’ reptiles associated with an assemblage of Rhaetian marine phytoplankton and land-derived palynomorphs. The marginal marine location of deposition deduced from the palynomorphs conflicts with the separation of late Triassic reptiles into ‘upland’ and ‘lowland’ regimens.