Abstract The famous Aust Cliff section, on the east bank of the River Severn, SW England,
includes one of the first documented successions through the Rhaetian stage (latest
Triassic) and a classic Triassic-Jurassic boundary section, and, historically, the first ever
mention and description of the Rhaetian bone bed, dating back to the 1820s. The larger
fossils, abraded vertebrae and limb bones of marine reptiles, have been widely reported, but
the microvertebrates from the Aust Cliff Rhaetian basal bone bed have been barely noted …