A monographic review of the Thermosbaenacea (Crustacea: Peracarida) A study on their morphology, taxonomy, phylogeny and biogeography

In addition to a taxonomic review of the whole order Thermosbaenacea, the general morphology and chaetotaxy are discussed in detail. Due to the results of cuticular staining, and through the study of specimens with SEM techniques also, corrections to earlier interpretations could be made. A chaetotaxic classification, modified after the one of Watling (1989), is presented. In the taxonomic part 34 species are recognized, belonging to seven genera (one new), four families (one new). The examination of adult material of the type species of Monodella, i.e., Monodella stygicola Ruffo, 1949, warranted the creation of Tethysbaena gen. nov., to comprise all other taxa previously included in Monodella. Transferred to Tethysbaena are: M. argentarii Stella, 1951; M. halophila S.L. Karaman, 1953; M. relicta Pór, 1962; M. sanctaecrucis Stock, 1976; M. somala Chelazzi & Messana, 1982; M. atlantomaroccana Boutin & Cals, 1985; and M. scabra Pretus, 1991. Additionally 15 new species of Tethysbaena are described: Tethysbaena juriaani spec. nov. (type species of the genus); T. gaweini spec. nov.; T. haitiensis spec. nov.; T. juglandis spec. nov.; T. lazarei spec. nov.; T. tinima spec. nov.; T. coqui spec. nov.; T. colubrae spec. nov.; T. scitula spec. nov.; T. calsi spec. nov.; T. stocki spec. nov.; T. tarsiensis spec. nov.; T. vinabayesi spec. nov.; T. aiakos spec. nov.; and T. siracusae spec. nov. The genus Tethysbaena can be divided into six species-groups. One new family, Tulumellidae, was erected for the species of the genus Tulumella Bowman & Iliffe, 1988. A second species of Limnosbaena Stock, 1976 (Halosbaenidae) is reported, but remains undescribed due to the severe damage of the single specimen available. A lectotype is designated for Theosbaena cambodjiana Cals & Boutin, 1985 (Halosbaenidae). All species are discussed with full reference to former publications, distribution, and habitat. Via a stepwise approach a hypothesized comprehensive phylogenetic tree is constructed with the PAUP computer program. In the biogeographic part, it is suggested that the actual distributions of the various thermosbaenacean species are the result of vicariance. The distributions are used in reconstructing origins of old tectonic plate fragments of the Tethys Sea belt, in particular those in the northern Caribbean region.