Overview of the cestode fauna of European shrews of the genus Sorex with comments on the fauna in Neomys and Crocidura and an exploration of historical processes in post-glacial Europe

The cestode fauna in shrews of the genus Sorex from the European region consists of seventeen species. Twelve cestode species have broad Palearctic distributions, three belong to the Western-Asian-European faunistic complex, and only two are endemic to the European zone. Postglacial expansion into the European territory resulted in geographic colonization by sixteen species. The large number of cestode species with transpalearctic ranges, as well as paleontological data indicating a nearly complete faunal turnover for species of Sorex in the Pleistocene, suggests that these parasites are more ancient than the assemblage of contemporary hosts in which they now occur, and thus represent ecological relicts. We suggest that origins of the cestode fauna pre-date those of the modern fauna of its hosts, and that initial formation and radiation occurred not later than the Pliocene. In the current review, we outline testable hypotheses to explore the structure, history and development of this fauna which appears limited to species of Sorex.