Contribution to the phylogenetic system of the Crinocheta (Crustacea, Isopoda). Part 1. (Olibrinidae to Scyphacidae s. str.)

Abstract

The phylogenetic relations between the families of Crinocheta (Isopoda, Oniscidea) are analysed. For each family, a description of a representative species, a reconstruction of the groundpattern (if possible), an estimation of species number and the geographic distribution are given. The morphological data were interpreted according to the method of Phylogenetic Systematics. The “Scyphacidae”, “Philosciidae”, “Dubioniscidae”, “Platyarthridae”, “Trachelipodidae”, and “Porcellionidae” proved to be paraphyla. The “Scyphacidae” were split into the monophyla Detonidae. Scyphacidae s. sir. and Alloniscidae. the latter belonging in the Oniscoidea. In the cladogram, the following taxa branch off successively: Olibrinidae. Detonidae, Scyphacidae str., Alloniscidae, then follows an unresolved trifurcation between Taxon 3 (including “Philosciidae”, Halophilosciidae, Scleropactidae), Stenoniscidae and Taxon 4 (all others). The Taxon 4 splits into Rhyscotidae and Taxon 6, the latter consists of Squamiferaee and Taxon 7. Within the latter, the resolution is low; a sistergroup relation between Armadillidae and Eubelidae can be assumed, a close affinity of Bathytropidae and Tendosphaeridae seems possible, the “Trachelipodidae” were split into the monophyletic Agnaridae, and the probably still paraphyletic “Trachelipodidae” s. str. The “Porcellionidae” are paraphyletic with respect to the Armadillidiidae. Some data on the biogeography of several taxa are discussed in the context of their phylogenetic relations.