Genus Petalophthalmus Willemoës-Suhm, 1874

Petalophthalmus Willemoës-Suhm, 1874: XIV [male only; females belong to Birsteiniamysis inermis (Willemoës-Suhm, 1874)]

Petalophthalmus – Willemoës-Suhm 1875: 43 (male only). — Perrier 1893: 1026. — Faxon 1895: 223. — Tattersall & Tattersall 1951: 120. — Pillai 1965: 1684 (partim). — O.S. Tattersall 1968: 273 (partim). — Panampunnayil 1982: 643 (partim). — Kathman et al. 1986: 214. — Bravo & Murano 1997 a: table 1. — San Vicente & Corbari 2015: fig. 8 (partim). — San Vicente 2017: 154. — Mees & Meland 2019 (in database).

Revised diagnosis

Petalophthalminae with antennal scale setose all around; eyes not miniaturized, nonetheless cornea reduced, without or with some scattered visual elements, together not forming a compound sensory organ; anterior margin of carapace without pair of distinct submedian processes, rostrum present or absent; lacinia mobilis absent in one mandible, developed in the other one; pars centralis absent or reduced to one spine (tooth, digitus); thoracic endopods 3–4 reduced to 1–2 short segments; thoracic endopods 5–8 slender, with more than five segments; flagellum of thoracic exopods 3–8 with 13–21 segments; pleopods biramous in males, biramous or uniramous in females; telson large, subquadrangular, terminal margin truncate with or without slight emargination, terminal margin without or with two submedian groups of small teeth, in any case with 7–13 large, toothed spines, without setae.

Type species

Petalophthalmus armiger Willemoës-Suhm, 1875 .

Distribution of the species included

Petalophthalmus armiger with panoceanic distribution, 56 ° N to 46° S, mesopelagic to abyssobenthic, 900–4572 m depth;

Petalophthalmus cristatus sp. nov. from the SE-Atlantic, Angola Basin, depth Ĺ 5497 m; Petalophthalmus papilloculatus San Vicente, Frutos & Cartes, 2014, from the NE-Atlantic, Galicia Bank off Iberian Peninsula, 1536 – 1809 m depth;

Petalophthalmus papuaensis San Vicente & Corbari, 2015, from the tropical W-Pacific, Bismarck Sea, 800– 1065 m depth.