Depth-related brachiopod-dominated benthic communities can provide well-dated indications of change in relative sea level, especially if they occur in tectonically stable regions. Eustatic changes in sea level occurred over short (less than 1–3 m.y.) intervals at the end of the Llandeilo, in the late Ashgill and at the base of the Upper Llandovery; they may be related to changes in the size of the icecap in Gondwanaland. In the Llandovery and in the late Silurian, there are periods of more prolonged eustatic changes in sea level. Other changes are shown to be restricted to a single continent, and suggest vertical movements with very little tilting.