The history of investigation of the Silurian rocks of the Dunquin inlier, Dingle Peninsula, County Kerry, Ireland is briefly reviewed. The Dunquin Group of upper Wenlock (Homerian) to middle Ludlow (Ludfordian) sedimentary and volcanic rocks is divided into five formations: the Ferriters Cove, Clogher Head, Mill Cove, Drom Point and Croaghmarhin Formations, the last of which reaches the Ludlow and passes transitionally into the succeeding continental Dingle Group, probably largely Přídolí in age. The Dunquin group is of varied shallow marine sediments with a continental episode probably represented in the Mill Cove Formation. The biostratigraphy of the other four formations is considered in relation to a full faunal list. Details of representative sections and exposures are provided. There is brief comment on the palaeogeographical setting of the inlier.

The available data from Newfoundland, the British Isles and Scandinavia suggest that by late Ordovician–early Silurian times the ocean separating Laurentia from Eastern Avalonia and Baltica had partly closed with the consumption of intervening oceanic crust. Marine seaways, however, persisted until the middle or late Silurian. Phases of crustal transtension and transpression, predominantly under a major sinistral shear couple, occurred throughout the Silurian and early Devonian until the remnant Iapetus Ocean was completely destroyed. The most appropriate Recent plate tectonic models for Silurian sedimentation between Eastern Avalonia and Laurentia are probably the deep-marine foreland basins between Timor and the northern Australian margin, or between Taiwan and mainland China.

A global review of new and existing data on the distribution of uppermost Ordovician (Hirnantian) brachiopods indicates the existence of at least three biogeographically distinct faunas. The typical Hirnantia fauna characterised subtropical and temperate latitudes and comprised a variety of ecological associations; the fauna reached its acme during the bohemicus and uniformis zones. Atypical Hirnantia faunas, developed marginal to Gondwana, are of low diversity and have few species in common with the typical Hirnantia fauna; their spatial distribution probably marked the margin of the polar ice sheets. The extinction of the Hirnantia fauna occurred in response to changes in sea level. Diverse and quite different faunas, including those from the Midcontinent of North America, Kolyma, the Oslo Region and probably Anticosti Island, occupied equatorial latitudes during the latest Ordovician. The Holorhynchus fauna, on evidence to date, predates the Hirnantia fauna.