Anaspidacea, Bathynellacea (Crustacea, Syncarida), generalised tracks, and the biogeographical relationships of South America

Abstract

The spatial evolution of South American Syncarida (Anaspidacea and Bathynellacea) and related taxa is evaluated applying a panbiogeographic approach, where Ocean basins are used to identify major patterns of intercontinental distribution. The Pacific basin, corresponding to a southern temperate track, is identified as the major evolutionary centre for Stygocaris (Stygocarididae), Bathynella (Bathynellidae), Atopobathynellu , and Chilibathynella (Parabathynellidae), whereas distribution of Nannobathynella (Bathynellidae) and Cteniobathynella (Parabathynellidae) is centred on the Atlantic Ocean, belonging to a northern tropical track. It is concluded that the biotic origin of the South American Syncarida is complex, implying the existence of at least two ancestral biotas.