Silurian Proporidae and Plasmoporidae (Anthozoa, Tabulata) from the Chaleurs Bay region, Canada

Abstract

Six species belonging to the families Proporidae and Plasmoporidae occur in the Lower and Upper Silurian rocks of the Limestone Point and La Vieille Formations of northern New Brunswick and of the Anse à Pierre-Loiselle, La Vieille, and Gascons Formations of the Gaspé Peninsula of Québec. The three species ofProporaare widely distributed but show varying faunal affinities, while both species ofPlasmopora, Plasmopora loganiandPlasmopora corrugata, are new and are almost endemic. Revised concepts ofProporaandPlasmoporaare proposed. The holotype specimen for the type species ofCamptolithuswas examined and confirms the genus as distinct fromPropora, rather than a synonym as has been previously suggested.The facies distribution of these corals is variable. In general, the proporids, which mostly occur in facies indicating shallow carbonate banks and patch reefs, are more restricted in distribution than the plasmoporids, which occur in these facies and also in others representing a variety of open-shelf environments.