Structure of the corallite wall of the Upper Ordovician and Silurian Favositidae (Tabulata) and its possible use in stratigraphic correlation

Based on an analysis of the significant collections of Favositidae (tabulate corals) from the Upper Ordovician-Lower Devonian of the Taimyr Peninsula, Western Slope of the North Urals and the Tchernychev Uplift, this paper focuses on the macro- and micro-structurе of the corallite wall. Seven structural types of the corallite wall have been recognized; some of them seem to have a definite stratigraphic range. The results contribute to the long-time discussion on the applicability of skeletal structure for systematics of the Favositidae, its evolutionary implications, and stratigraphic correlation. It has been held that the skeletal structure of the fossilized remains of Favositidae is inapplicable for such purposes because diagenetically, it is secondary, being a product of mineral replacement of the primary structure. In contrast, an assumption is made here that the “secondary” skeletal macro- and micro-structure may reflect in some way the “primary” skeleton. As a result, it is proposed that some evidence of evolution of the Favositidae may be obtained by evaluating the stratigraphic range of favositid representatives possessing different types of structure of the corallite wall.