All well-dated occurrences of Upper Devonian septate corals (subclass Rugosa) are analyzed at species and higher taxonomic levels. Platform-dwelling corals are differentiated from the less numerous basin-dwelling corals.Through early and middle Frasnian time, evolution outpaced the extinction of rugose corals, so that late Frasnian faunas were more diverse than the earliest Frasnian faunas. This gradual increase of genera was terminated abruptly by an almost complete extinction of late Frasnian platform-dwelling Rugosa in uppermost gigas to lower Palmatolepis triangularis Zone time. None of the 151 species, and probably as few as two or three, at most five, of the 47 genera of late Frasnian shallow-water corals survived this event. The loss of coral biomass was equally devasting. Very few early Famennian platform-dwelling corals are known, although platform carbonates of this age were deposited in several regions. Platform faunas, comprising 66 species and 27 genera, reappeared in late Famennian time. These faunas were unrelated phylogenetically to known Frasnian faunas but were forerunners of shallow-water Carboniferous faunas.Basin-dwelling Rugosa were affected little by the late Frasnian extinction event: all 12 Frasnian genera survived it.Rugose coral data provide compelling evidence for a major late Frasnian extinction of shallow-marine benthos without suggesting a unique cause of it. The data are consistent with results expected of an asteroid impact or a rapid decline of ocean temperature, especially in regard to the very much higher survival rate among basin-dwelling corals. However, the data are not controlled by a sufficiently refined time scale to prove the geological instantaneity of such an event.

Detailed analysis of the stratigraphic ranges of Devonian rugose coral genera within the Old World and Eastern Americas Realms gives new information on faunal extinctions and other bioevents in both realms. Various origination and extinction metrics are calculated from tabulations of occurrences in each stage. The most significant faunal changes were near or at the ends of the Lochkovian and Frasnian stages. The former marks the gradual transition from dominance by Silurian families and genera to the characteristic Devonian coral assemblages; the latter marks the virtual extinction of the Devonian families and genera. Other coral events are related to the two major changes.The data provide new bases for comparing the histories of the two realms. Most of the events are recorded in both, giving support to previous suggestions that the causes were worldwide. The coral record shows an increase (probably episodic) in environmental deterioration persisting through the Middle Devonian and culminating in extinction at the end of the Frasnian. Eustatic sea level fluctuations may have caused the precursor events and a bolide impact may have caused the end-Frasnian extinction.

A data bank, based on stage by stage distributions of 420 rugose coral genera in 25 regions of the world is analysed, mostly by means of Otsuka coefficients, to test an Emsian reconstruction of the world proposed by Scotese. Devonian rugose corals inhabited a narrower range of facies than some other benthic groups, and even without regard to facies, provide a tool for testing geographic reconstructions. Basin dwelling coral genera typically have longer temporal and broader geographic ranges than corals living in shallower environments, and are less suitable for palaeogeographic studies. They are treated separately in this work.For the most part, conclusions drawn from the analysis are either consistent with, or positively supportive of, the Scotese reconstruction. However, large but poorly known rugose coral faunas from Mongolia and the Amur Basin are at about 60~ in the reconstruction, and other well known coral faunas, from Altai-Sayan, are at 45~176In the light of known distributions of both modern corals and Devonian southern hemisphere corals, in all recently proposed palaeogeographic reconstructions, it is questionable that the original latitude of any large northern hemisphere Devonian coral fauna would have exceeded 45 ~ .

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