Abstract

New records of Palaeocampa anthrax Meek&Worthen, 1865 with fossilized soft parts are provided from Montceau-les-Mines in France, late Carboniferous, permitting the identification of a new clade of extinct amphinomid polychaetes. The group also provides an object lesson for problems with species concepts in palaeontology. The biological species concept, the diagnosable phylogenetic species concepts, and the monophyletic phylogenetic species concepts are applied and discussed in the case of P. anthrax, as well as more generally in palaeontology. All three are rejected, but for different reasons. Instead we advocate the application of LITUs (least inclusive taxonomic unit), which refers to the smallest currently recognised taxa, but without making the unjustified rank assignments to species.