Tanaidomorphan systematics - Is it obsolete?

Abstract

A new species of the genus Bathytanais is described and its impact on the unstable taxonomy of the family Paratanaidae is discussed. A full description of the adult female and the manca of Bathytanais juergeni, new species, is presented. Males remain unknown for the genus. Scanning electron micrographs of B. juergeni reveal that the carapace consists of articulated plates, not a uniform carapace, and that the coxae of pereiopods 4-6 are expanded to form sternal plates. The genus Bathytanais is retained in the family Paratanaidae, but the family is redefined. The related families/sub-families Anarthruridae, Typhlotanaidae, and Leptognathiinae are critically reviewed. The taxonomic concepts that were suggested by Sieg for the above-mentioned families fail when setal homologies are critically evaluated. The number of articles in the uropodal rami, often used in generic and family diagnoses, is found to be ambiguous, owing to partial fusion of articles.