Brevitalitridae, Myers & Lowry, 2020

Myers, A. A. & Lowry, J. K., 2020, A phylogeny and classification of the Talitroidea (Amphipoda, Senticaudata) based on interpretation of morphological synapomorphies and homoplasies, Zootaxa 4778 (2), pp. 281-310 : 301-302

Brevitalitridae fam. nov.

Type genus. Brevitalitrus Bousfield, 1971

Included genera (9). Bousfieldia Chou & Lee, 1996 ; Brevitalitrus Bousfield, 1971 ; Caribitroides Lindeman, 1990 ; Cerrorchestia Lindeman, 1990 ; Hawaiorchestia Bousfield, 1984 ; Mexitroides Lindeman, 1990 ; Mizuhorchestia Morino, 2014 ;? Spelaeorchestia Bousfield & Howarth, 1976 ; Talitroides Bonnier, 1898 .

Category. Mascupods and femipods.

Ecological type. Field-hoppers, forest-hoppers and moss-hoppers.

Distribution. Australia and Papua New Guinea; Western Indian Ocean; Japan and Taiwan; Pacific Plate; Caribbean.

Diagnostic description. Antenna 1 long, reaching to at least midpoint of peduncular article 5 of antenna 2 or short, not reaching midpoint of peduncular article 5 of antenna 2. Maxilliped palp article 2 without distomedial lobe; article 4 small, distinct. Gnathopod 1 posterior margin of merus, carpus and propodus each without palmate lobes or posterior margin of merus, carpus and propodus each with palmate lobes; propodus subrectangular or ‘subtriangular’ with well-developed posterodistal lobe or subrectangular, tapering distally. Gnathopod 2 subchelate or mitten-shaped. Pereopods 3–7 cuspidactylate. Pereopod 4 dactylus amplidactylate. Pereopod 5 dactylus not inflated. Pereopod 6 subequal in length or shorter than pereopod 7. Pereopod 7 not sexually dimorphic. Epimera 1–3 slits absent. Uropods 1–2 rami without apical spear-shaped setae. Uropod 1 male exopod not sexually dimorphic; exopod with marginal robust setae in one row or without marginal robust setae. Uropod 3 ramus shorter than peduncle. Telson with only apical robust (except Brevitalitrus ); with 1–6 robust setae per lobe.

Remarks. Bousfield (1984: table 8) describes pereopods 3–7 as cuspidactylate for Spelaeorchestia and this in association with other characters (antenna 1 short, maxilliped palp article 2 without distomedial lobe, uropod 1 exopod without marginal setae and telson with 3 robust setae per lobe) places it in either the Brevitalitridae or the Makawidae . Both families contain femipods. We are unable to separate the Makawidae and Brevitalitridae on morphological character states, but they have very different distributions. The Makawiidae are found only in Zealandia ( New Zealand, New Caledonia and Lord Howe) and Tasmania. The Brevitalitridae , by contrast are almost world- wide from South and Central America, through Taiwan and Japan to Hawaii and across many islands on the Pacific Plate as well as in the Indian Ocean.

Based on biogeography we tentatively place Spelaeorchestia in the Brevitalitridae .