AN OVERVIEW OF THE SERPHITIDAE AND STIGMAPHRONIDAE (HYMENOPTERA) FROM CANADIAN CRETACEOUS AMBER

Recent work upon two extinct families of parasitoid wasps in Canadian Cretaceous amber has provided new insights into the temporal and paleobiogeographic distribution of taxa within these enigmatic families. Members of the Serphitidae and Stigmaphronidae are known exclusively from Cretaceous amber deposits. Canadian amber (Campanian, Late Cretaceous) currently provides the last records for these families prior to the Cretaceous-Tertiary mass extinction, and the only records on the western side of the Western Interior Seaway. To date, sixty individuals representing six serphitid species, and four individuals representing four stigmaphronid species have been discovered in Canadian amber. The relative abundance and diversity of these two families, as preserved in Canadian amber, differs significantly from the assemblages found in Spanish amber (Early Albian, Early Cretaceous) and New Jersey amber (Turonian, Late Cretaceous). Possible explanations for these discrepancies include differences in the availability of host taxa for the wasp families; a different type of amber-producing forest, set within a slightly different environment; or limitations attributable to either the paleobiogeographic or temporal ranges of the taxa examined.