A Phylogeny and Classification of the Senticaudata subord. nov (Crustacea: Amphipoda)

The Amphipoda includes a large clade defined by the presence of a previously unrecognised synapomorphy, apical robust setae on the rami of uropods 1-2. We term this clade the Senticaudata subord. nov. (Latin: sentis = thorn). It includes almost all freshwater species as well as a number of marine benthic taxa, formerly part of the 'Gammaridea'. The phylogeny of the senticaudates was determined by cladistic analysis of morphological characters and character states. Within the suborder Senticaudata there are six infraorders: Carangoliopsida, Talitrida, Hadziida, Corophiida, Bogidiellida and Gammarida. A classification is provided and all the senticaudate families are diagnosed. We introduce for the first time in amphipod classification, the level parvorder between infraorder and superfamily. Four new families are described: Kairosidae; Eriopisidae; Nuuanuidae and Kergueleniolidae.