Xoconochcothelphusa, a new genus for Ehecatusa chiapensis (Rodríguez & Smalley, 1972), with notes on Spirothelphusa Pretzmann, 1965 (Crustacea: Decapoda: Pseudothelphusidae)

The species of the genus Ehecatusa Ng & Low, 2010, E. chiapensis (Rodríguez & Smalley, 1972) and E. mixtepensis (Rodríguez & Smalley, in Smalley, 1970), were referred to as incertae sedis in the classification system of the tribe Pseudothelphusini Ortmann, 1897, proposed by Villalobos-Hiriart (2005) and Villalobos & Alvarez(2010) and as members of the subfamily Pseudothelphusinae in the recent phylogenetic proposal by Álvarez et al. (2020), supported with morphology and molecular information. The recent discovery of a new specimen of E. chiapensis, from Chiapas, Mexico, comes to expose again the unresolved taxonomic situation of this species in the genus Ehecatusa. New morphologic evidence from the male first gonopod and a phylogenetic analysis based on partial DNA sequences of mitochondrial and nuclear genes (COI, 16S and H3), support the placement of the two species in different genera. Consequently, Xoconochcothelphusa n. gen. is erected to receive X. chiapensis n. comb. The phylogenetic relationships of X. chiapensis n. gen., n. comb. and E. mixtepensis with other genera of the subfamily Pseudothelphusinae Ortmann, 1893 (Ehecatusa, Smalleyus Alvarez, 1989, and Spirothelphusa Pretzmann, 1965) distributed in Mexico, are examined and a key to the identification of the genera of this subfamily is provided.