Remarks on lithostrotionid phylogeny in western North America and western Europe

摘要

Faunal exchange between Tournaisian-Visean corals of western North America and Europe was limited by paleoenvironmental factors and by the great distance between those faunas, which were separated by the land-mass of Euramerica. Morphological comparison indicates that there is no direct relationship between species groups traditionally assigned to Siphonodendron in those areas. The immature morphology and stratigraphic distribution of the genus Dorlodotia suggest that it is the common ancestor for Siphonodendron in Europe and for Siphonodendron-like species in western North America. An unnamed, Ivorian species of Dorlodotia from western Canada initiated the phylogenetic succession, which led to the North American Siphonodendronli ke lineage in the latest Tournaisian and subsequently to the European Siphonodendron li neage in the early Visean.