Nanoplax thomai n. sp. is described from the Gulf of Mexico, representing the second species of the genus. The description is based upon a number of specimens previously misidentified as Micropanope truncatifrons Rathbun, 1898, including one so represented in recent molecular phylogenetic analyses. As restricted, Micropanope truncatifrons remains known with certainty from only the limited type series, which does not include a mature male, and sequence quality tissues are not available for molecular phylogenetic analyses. Its generic placement remains questionable following morphological study of its type materials and comparisons to specimens representing other present and former members of Micropanope Stimpson, 1871. Those comparisons underscore that morphological and molecular distinctions warrant assignment of Micropanope pusilla A. Milne-Edwards, 1880 to a new genus, herein designated as Pseudopanopeus n. gen.
Keywords: Crustacea, Pseudorhombilidae, Gulf of Mexico, Nanoplax, new species, generic revision
Nanoplax thomai n. sp.
Etymology. The species is named for Brent P. Thoma in recognition of his substantial contributions to understanding of xanthoid crab phylogenetic relationships and in gratitude for the many ways in which he has facilitated the present author’s work over the last decade
|Pseudopanopeus pusillus n. comb.|
male, cw 5.6 mm (ULLZ 14362 = USNM 1536353) northeastern Gulf of Mexico;
Pseudopanopeus n. gen.
Etymology. The prefix “pseudo”, for false, is paired with the suffix “panopeus”, derived from the type genus of Panopeidae Ortmann, 1893. As the gender is masculine, its combination with the type species name becomes Pseudopanopeus pusillus (A. Milne-Edwards, 1880). While resembling panopeids in general habitus and long grouped among members of that family, this genus is one of several such that instead fall among Pseudorhombilidae in the phylogenetic analyses of Thoma et al. (2014).
Pseudopanopeus pusillus (A. Milne-Edwards, 1880) n. comb.
Micropanope pusilla A. Milne-Edwards, 1880
Darryl L. Felder. 2020. A New Crab of the Genus Nanoplax from the Gulf of Mexico, and Assignment of Micropanope pusilla to A New Genus (Crustacea, Brachyura, Pseudorhombilidae). Zootaxa. 4810(3); 531–545. DOI: 10.11646/zootaxa.4810.3.9