Mokayathelphusa Moreno, Villalobos & Álvarez, 2022

Moreno-Juárez, Eric G., Villalobos, José Luis & Álvarez, Fernando, 2022, Two new genera and one new species of freshwater crabs of the subfamily Pseudothelphusinae (Decapoda: Brachyura: Pseudothelphusidae) from southwestern Mexico, Zootaxa 5200 (1), pp. 24-36 : 27-28

Mokayathelphusa Moreno, Villalobos & Álvarez n. gen.

urn:lsid:zoobank.org:act:A06B6E9E-4953-4B25-9DC9-3F1C592ACF4F

Diagnosis. G1 with the distal portion of principal axis twisted counterclockwise. Apical cavity oriented mesocephalically, compressed and closed cephalically by the internal angle of mesial process. Caudo-marginal projection trilobed distally, middle and distal lobes spiniform of same length, proximal lobe as elongated sheet, curved, extending through distal third of main gonopod axis. Mesial process large, subrectangular, with lateral margin ornamented with several spiniform teeth.

Type species. Mokayathelphusa angelsotoi n. sp., by present designation.

Etymology. The name of the genus is taken from the ancient tribe “Mokaya” that inhabited the Chimalapas region about 3,600 ybp. The word “Mokaya” comes from the earliest Zoque language, that means “people of the corn”. The gender of this name is feminine.

Distribution. Currently known only from the municipality of Santa María Chimalapa, State of Oaxaca, Mexico.

Remarks. The description of Mokayathelphusa n. gen. is justified by its unique male G1 morphology and clear genetic separation from related genera. The new genus can be related to other genera of the subfamily Pseudothelphusinae by the presence of the caudo-marginal projection, which ends distally in a trilobed distal plate. The phylogenetic analysis ( Fig. 2 ) recovers it as the sister lineage to Disparithelphusa Smalley & Adkison, 1984 . Morphologically the G1 of both genera present a torsion that modifies the shape and orientation of the apical cavity and have a trilobed distal plate in the caudo-marginal projection, where the distal lobes are smaller than the proximal one. They can also be differentiated by the size of the mesial process and the ornamentation of its lateral border, while in Disparithelphusa it is small, oval and without lateral ornamentation; in Mokayathelphusa n. gen., it is evidently developed and ornamented laterally.

Figures

FIGURE 2. Consensus tree resulting from ML and BI analyzes of the concatenated matrix (COX 1, 16S and H3) from the genus of the Pseudothelphusinae subfamily.