This monograph describes early Ordovician (Ibexian: Tremadocian–early Floian) trilobites from Northern Spitsbergen from the section through the Kirtonryggen Formation adjacent to Hinlopen Strait. The Formation is divided into three Members, each with distinct trilobites collectively representing the fullest known succession from the Bathyurid biofacies of the eastern Laurentian carbonate platform. Previous research on the Ordovician of Spitsbergen is summarised and correlations with similar faunas previously described from Canada, Greenland, western Newfoundland, Vermont–New York State, Oklahoma and Missouri are discussed. Taxonomic problems are discussed in detail leading to the recognition of 53 species, of which 15 are new, belonging to 31 genera including four new. Twenty-four taxa are described under open or tentative nomenclature. The lower Member yields the earliest known occurrences of the Illaenoidea, Proetoidea and Scutelluoidea, supporting the hypotheses relating the origin of new major clades to inshore habitats.

The Ordovician was one of the longest of the geological periods, characterized by major magmatic and tectonic activity, an immense biodiversification, swings in climate and sea levels, and the first Phanerozoic mass extinction. ‘A Global Synthesis of the Ordovician System’ is presented in two volumes in The Geological Society, Special Publications. Whereas the first volume (SP532) concentrates on general aspects and a synthesis of the Ordovician geology of Europe, this volume (SP533) includes reviews of Ordovician successions of most other parts of the world. The classic successions of the Ordovician basins of North America are presented, as well as those of China where several of the Ordovician Global Boundary Stratotype Sections and Points are defined. The volume also includes syntheses of the Ordovician geology of Africa, South America, most regions of Asia from the Near to the Far East along with Central Asia, as well as Australia, New Zealand and Antarctica.

The trilobites from the Upper Cambrian to Lower Ordovician Survey Peak, Outram and Skoki formations at Wilcox Pass, Alberta, comprehensively described in this report, belong to 48 genera. One new genus and six new species are described, and type material for seventeen previously described species from corresponding strata elsewhere in the Rockies is redescribed or re-illustrated. This report establishes a biostratigraphic framework for the Wilcox Pass sequence, from the highest part of the Upper Cambrian Trempealeau Series through the entire Lower Ordovician, based on trilobite zones.