Pseudothelphusa sulcifrons, Rathbun, 1898

Villalobos, José Luis & Alvarez, Fernando, 2010, Phylogenetic analysis of the Mexican freshwater crabs of the tribe Pseudothelphusini (Decapoda: Brachyura: Pseudothelphusidae), Zoological Journal of the Linnean Society 160 (3), pp. 457-481 : 474

PSEUDOTHELPHUSA SULCIFRONS

Node 8, supported by ten characters, defines the main group of species within the Pseudothelphusini , P. sulcifrons and the two most species-rich genera Tehuana and Pseudothelphusa . Two synapomorphies give support to this group: a bilobed caudo-marginal projection (character 47) and a cephalically oriented proximal lobe (character 54). The remaining eight characters describe the typical gonopod of the Pseudothelphusini : U- or V-shaped notch dividing the two lobes of the caudo-marginal projection (character 49); distal lobe of the caudo-marginal projection ending in a rounded lobe (character 50), oriented cephalically (character 52); in mesial view proximal lobe of the caudo-marginal projection oblique with respect to the main axis of the gonopod (character 53), with a smooth cephalic margin (character 55) and a shallow border on the internal surface (character 57).

Pseudothelphusa sulcifrons stands out from Pseudothelphusa because of the presence of a short incision separating the lobes of the caudo-marginal process of the gonopod (character 51), a distal lobe of the caudo-marginal projection curved proximally (character 52), the presence of a rounded lobe on the caudal surface of the mesial process (character 69), and a curved inferior margin of the mesial process (character 71). Based on this character combination, P. sulcifrons should be placed in a new genus.