Pseudorchestoideinae subfam. nov.

Type genus. Pseudorchestoidea Bousfield, 1982 .

Included genera (6). Americorchestia Bousfield, 1991; Asiaorchestia Lowry & Myers, 2019a; Britorchestia Lowry & Bopiah, 2012; Persianorchestia Momtazi, Lowry & Hekmatara, 2017; Pseudorchestoidea Bousfield, 1982; Sardorchestia Ruffo in Tafani et al., 2004 .

Category. Mascupods.

Ecological type. Sand-hoppers.

Distribution. Persian Gulf; Pacific South and Central America; Indonesia and Malaysia; East Atlantic and Mediterranean; Western North Atlantic.

Diagnostic description. Antenna 1 short, not reaching midpoint of peduncular article 5 of antenna 2. Maxilliped palp article 2 with distomedial lobe; article 4 reduced, button-shaped or fused to article 3. Gnathopod 1 posterior margin of carpus and propodus each with lobe covered in palmate setae; propodus subrectangular. Gnathopod 2 subchelate. Pereopods 3–7 cuspidactylate. Pereopod 4 dactylus amplidactylate. Pereopod 5 dactylus not inflated or inflated. Pereopod 6 subequal in length to pereopod 7. Pereopod 7 not sexually dimorphic. Epimera 1–3 slits absent. Uropods 1–2 rami with apical spear-shaped setae. Uropod 1 male exopod not sexually dimorphic; exopod with marginal robust setae in one row or with marginal robust setae in two rows or without marginal robust setae. Uropod 3 ramus subequal in length, longer than or shorter than peduncle. Telson with apical and marginal robust setae, with 3 to at least 10 robust setae per lobe.

Remarks. Pseudorchestoideini is defined by the unusual spear-shaped apical setae on the rami of uropods 1 and 2. The group follows the ancient southern Laurasian coastline from tropical America through the Mediterranean Sea, the Persian Gulf to Vietnam.