Tirons of the world: a review of ‘tironid’ amphipods, description of new genera and species, and establishment of a new subfamily Tironinae Stebbing, 1906 stat. nov. (Crustacea, Synopiidae)

The classification of a group of Synopiidae is reviewed based primarily on new material from Australasia and the northern Pacific. A synopiid subfamily, Tironinae Stebbing, 1906 stat. nov. is diagnosed for the following six genera (3 new) consisting of 38 species (18 new): Tiron Lilljeborg, 1865, with 6 species, T. spiniferus Stimpson (type species), T. antarcticus K.H. Barnard, 1932, T. biocellatus J.L. Barnard, 1962, T. canadense sp. nov., T. lilljeborgi sp. nov., and T. sagamiense sp. nov.; Tironella gen. nov. with 3 species, T. altifrons (Reid, 1951, ex Tiron) comb. nov., T. bathyalis sp. nov. (type species), and T. pervicax (J.L. Barnard, 1967, ex Pseudotiron) comb. nov.; Glandulotiron gen. nov. with 15 species, G. pilocaputis sp. nov. (type species), G. salsevisio sp. nov., G. hexamatius sp. nov., G. spinipes sp. nov., G. concavus sp. nov., G. septimus sp. nov., G. meruspinosus sp. nov., G. bassianus sp. nov., G. curvispinus sp. nov., G. aotearoensis sp. nov., G. postremus sp. nov., G. griffithsi sp. nov., G. intermedius (Reid, 1951; ex Tiron) comb. nov., G. quadrioculatus (Dang & Le, 2012; ex Tiron) comb. nov., and G. australis (Stebbing, 1908; ex Tiron) comb. nov.; Pseudotiron Chevreux, 1895 with 4 species, P. bouvieri Chevreux, 1895, P. coas J.L. Barnard, 1967, P. golens J.L. Barnard, 1962, P. miratus sp. nov.; Metatiron Rabindranath, 1972, with 4 species, M. brevidactylus (Pillai, 1954, type species), M. bonaerensis Alonso de Pina, 1998, M. triocellatus (Goeke, 1982) and M. tropakis (J.L. Barnard, 1972); and Minitiron gen. nov. with 6 species, M. orpheus sp. nov. (type species), M. bellairsi (Just, 1981; ex. Metatiron) comb. nov., M. caecus (Ledoyer, 1979; ex. Metatiron) comb. nov., M. galeatus (Hirayama, 1988; ex Tiron) comb. nov., M. ovatibasis (Hirayama, 1988; ex Tiron) comb. nov., M. thompsoni (Walker, 1904; ex Tiron) comb. nov. Three species currently in Pseudotiron (P. longicaudatus Pirlot, 1934; P. sublongicaudatus Dang & Le, 2012; P. livingstonae Lörz & Coleman, 2013) are removed to Synopiidae incertae sedis. Metatiron brevidactylus (Pillay, 1957) by Ledoyer (1979) is removed to Minitiron incerta sedis. Species in the new genus Glandulotiron and a new species of Pseudotiron possess rows of elongate glands in uropods and the telson previously unknown in amphipods. A new key is presented for synopiid genera together with a key to world tironin genera and separate keys for the individual tironin genera. Global distribution and more detailed Australian distribution of the tironins are shown.