British Ordovician Tabulate Corals

Abstract

ABSTRACT Of the 13 families of tabulate corals represented in the Ordovician successions of South and North Wales, Lake District, Northwest Yorkshire, Cross Fell and Southwest Scotland, three (Cryptolichenariidae, Lichenariidae, Paleoalveolitidae) are exclusive to the Caradoc Series, being the oldest tabulate corals recorded from Britain, five (Favositidae, Proheliolitidae, Proporidae, Sibiriolitidae, Taeniolitidae) are exclusive to the Ashgill Series, while the remaining five (Billingsariidae, Coccoserididae, Halysitidae, Syringophyllidae, Tetradiidae) are represented in both the Caradoc and Ashgill series. The total known fauna consists of 26 genera, of which Elkanpora and Girvanopora are new. Of the 63 species and subspecies, two are described under open nomenclature and 25 are new The palaeogeographical distribution of these tabulate corals was affected by the separation of the Laurentia and Avalon palaeocontinents in Caradoc and Ashgill times, the Iapetus Ocean acting as a barrier that prevented the mixing of their coral faunas.