Systematics and evolution of agetolitid tabulate corals

Agetolitids are a distinctive, internationally widespread favositid tabulate coral group, with an age range restricted to the Katian (Late Ordovician). Their taxonomy and evolution have not been revised for almost half a century. In this work, the published, mostly type, material of this group deposited in palaeontological institutions in China and Australia, representing the bulk of named taxa, is systematically reassessed, and many of these are thereby critically revised. Such a revision, along with consideration of other published information, supports the subdivision of the Agetolitidae into two subfamilies, Agetolitinae and Hemiagetolitinae, which comprise Agetolites and Subagetolites, and Agetolitella and Agetolitoides, respectively. Within the current stratigraphic and tectonic framework, this study also outlines stratigraphic records and hence the evolutionary history of agetolitid corals using the new fossil data. The results show that this fossil group might have originated in North China during the early Katian and had occupied almost all low-latitude blocks/terranes by the late Katian. However, agetolitids failed to survive the End Ordovician Mass Extinction that took place around the Katian–Hirnantian boundary.