This is the eighth volume in the series of catalogues detailing the type of invertebrate fossils in the GSC collection in Ottawa. The catalogue mainly includes all fossils described between late 1981 and 1990. Descriptions or illustrations of fossils listed in previous volumes but redescribed during the period are also included. Primary type categories Holotype, Paratype, Syntype, Lectotype, Neotype, and secondary Hypotype, Topotype, and figured specimens are used with the same connotations as in previous volumes. The original reference for each species is cited as well as subsequent reviews directly involving the forms listed.

Receptaculitids are extinct high-level fossils that provide a window into the history of life. After the discovery and analysis of a deposit of phosphatized receptaculitids on the Baltic Sea island of Öland, the authors conclude that receptaculitids possess an attribute not found in any other group of organisms, living or fossil.