Parapinnixa Holmes, 1894

Hernández-Ávila, Iván & Campos, Ernesto, 2007, Parapinnixa bolagnosi, a new species of pinnotherid crab from Cubagua Island and Los Frailes Archipelago, Venezuela (Crustacea: Brachyura: Pinnotheridae), Zootaxa 1607, pp. 57-62 : 58

Parapinnixa Holmes, 1894

Type species. By monotypy Pinnixa ? nitida Lockington, 1876.

Emended diagnosis (modified from Rathbun, 1918; modification indicated by underlining). Carapace calcified, much broader than long, anterior margin nearly straight, frontal process deflexed. Orbits nearly round. Antennules oblique or transversally plicate, fossettes communicating with each other beneath front. Buccal area small, very broadly triangular. External third maxilliped with ischium rudimentary, merus large, sub-triangular; palp two or three articles, terminal segment joined to tip of preceding one; exopod, when present, without flagellum. First leg largest, others successively diminishing in length, last pair very small. Abdomen of female, small, not covering sternum. Abdomen of male with telson rounded.

Distribution and host. Atlantic Ocean: North Carolina to Brazil. Pacific Ocean: California to Galápagos Is. A presumed extralimital record to SE Siberia. With Polychaeta;? Echinoidea ( Schmitt et al. 1973; Thoma et al. 2005).

Taxonomic remarks. Despite having MXP3 with two articles, several other outstanding features support the inclusion of our material in the genus Parapinnixa . These include a carapace broader than long and calcified, buccal region very small and triangular, MXP3 with rudimentary ischium, merus larger and triangular and the relative length of the WL 1> 2> 3> 4. However, the generic characters MXP3 palp with three articles inserted end to end and exopod without a flagellum do not apply to this species, which has a palp with only two articles without an exopod. Instead of erecting a new, and probably paraphyletic, genus for this atypical species, we chose to emend the diagnosis of Parapinnixa to accommodate it.

Other genera of Pinnotheridae with the palp of the MXP3 composed by two or three segments include Calyptraeotheres Campos, 1990 (see Campos 1999; Hernández-Ávila & Campos 2006) and Dissodactylus Smith, 1870 (see Griffith 1987).