Examination of the upper surfaces of 27 high-domical stromatoporoids from the Silurian Upper Visby Beds of Gotland reveals that they were densely encrusted by a wide variety of epifaunal organisms. These organisms showed clear preferences for either the apical or the basal portions of the coenosteum, and though the diversity of the lower-flank fauna was greater, coverage by encrusters was twice as dense at the apex. This is shown to have been due to the progressive burial of the substrates. Although most encrustation was opportunistic, a few species are shown to have been “pioneers”, while others were consistently late in developing. Spirorbid worms were gregarious in their late larval stages, leading to clumped distributions. The stromatoporoids themselves bear radial fractures which were clearly caused before burial and even prior to encrustation. Such cracks are easily distinguished from those due to compaction by overburden.