Published online by Cambridge University Press: 20 May 2016
The Chesterian Imo Formation of northern Arkansas represents the highest Mississippian strata present on the Ozark platform and contains a unique, although sparse, coral fauna that is transitional between Mississippian and Pennsylvanian assemblages. Of the four most abundant genera represented, Lophophyllidium, Bradyphyllum, and Tectamichelinia are characteristic of Pennsylvanian assemblages and only Amplexizaphrentis is a typical Mississippian form. The fauna is interpreted as part of a shallow-water, muddy bottom community. Of the 11 rugosans and single tabulate coral described, the following are new: Bradyphyllum lesliense n. sp., Amplexizaphrentis maneri n. sp., Lophophyllidium imoense n. sp., and Tectamichelinia mangeri n. gen. and sp.