Variation in the Silurian tabulate coral Paleofavosites asper, and the status of Mesofavosites

Paleofavosites asper (d'Orbigny) is redescribed on the basis of the holotype and additional material from its type area of the Welsh Borderland. The species shows considerable variation, particularly in the form and location of intercorallite pores, from colonies with pores, including a high proportion of solenia, almost exclusively located in corallite angles to those with up to 40% of pores within corallite walls. This species, the type species of Paleofavosites Twenhofel, 1914 includes variants with the structural features considered characteristic of Mesofavosites Sokolov, 1951. We therefore regard Mesofavosites as a junior subjective synonym of Paleofavosites.