Evidence for phylogenetic analysis comes in the form of observed similarities, and trees are selected to minimize the number of similarities that cannot be accounted for by homology (homoplasies). Thus, the classical argument for parsimony directly links homoplasy with explanatory power. When characters are hierarchically related, a first character may represent a primary structure such as tail absence/presence and a secondary (subordinate) character may describe tail colour; this makes tail colour inapplicable when tail is absent. It has been proposed that such character hierarchies should be evaluated on the same logical basis as standard characters, maximizing the number of similarities accounted for by secondary homology, i.e. common ancestry. Previous evaluations of the homology of a given ancestral reconstruction contain the unintuitive quantity "subcharacters" (number of regions of applicability). Rather than counting subcharacters, this paper proposes an equivalent but more intuitive formulation, based on counting the number of changes into each separate state. In this formulation, x-transformations, the homoplasy for the reconstruction is simply the number of changes into the state beyond the first, summed over all states. There is thus no direct connection between homoplasy and number of steps, only between homoplasy and extra steps. The link between the two formulations is that, for any region of applicability of any character, a subcharacter can be interpreted as the change into the state that is plesiomorphic in that region. Although some authors have claimed that the equivalence between maximizing explanatory power and minimizing independent originations of similar features (i.e. the standard justification of parsimony) does not hold for inapplicable characters, evaluating homoplasy with x-transformations clearly connects the two sides of that equation. Furthermore, as the evaluation with x-transformations provides a direct count and a straightforward interpretation of homoplasy, it extends naturally into implied weighting, and sheds light on problems with additive, step-matrix or continuous characters. It also allows deriving transformation costs for recoding hierarchies as step-matrix characters (where recoded states correspond to permissible combinations of states in primary and secondary characters), so that homology of the original observations is properly measured. Those transformation costs set the cost of gaining the primary structure to the maximum difference between "present" states plus cost of loss, and difference between "present" states to the sum of user-defined transformation costs between secondary features. With such recoding, invoking multiple independent derivations of the structure and similar features will cost as many extra "steps" as the instances of similarities (in both original characters) that are not being homologized. The step-matrix recoding also can take into account nested dependences. We present a simple convention for naming characters, which TNT can use to automat...

with a 2500 Moticam camera of 5.0 M pixels coupled to a stereoscopic MOTIC trinocular/SMZ-168 and a microscope Olympus CX21. The notation for leg spines follows Goloboff & Platnick (1987); variation in the sides of a specimen (in number of spines, cuspules, or teeth) is indicated as two numbers or formulae separated by a slash (/); when describing variation in chaetotaxy, only surfaces with different numbers of spines are listed.Collection sites were georeferenced by finding the locality specified on the label in Google Earth® and then the coordinates were recorded.The cladistic analysis was carried out with the program TNT version 1.5 (Goloboff, Farris & Nixon 2008; Goloboff & Catalano, 2016), using equal-weights parsimony as the optimality criterion.Abbreviations: ALE anterior lateral eyes; AME anterior median eyes; D dorsal; D ANT dorsal anterior; D B dorsal basal; P prolateral; P A INF prolateral apical inferior; P INF prolateral inferior; PLE posterior lateral eyes; P M prolateral medial; PME posterior median eyes; P SUP prolateral superior; R retrolateral; R INF retrolateral inferior; R SUP retrolateral superior; V ventral; V A ventral apical; V ANT ventral anterior; V POST ventral posterior; 1:2 A, 3:4 B, indicate that the spines or scopulae referred to are in the apical half or basal third-fourths. The following abbreviations were taken (or modified) from Coyle (1981): ITL distance from crotch to tip of tibial spur; ITA distance from proximal end of line defining the tibial length to the right-angle intersection of that line and one passing through crotch at base of tibial spur; ITB distance from spur crotch to distal end of tibia on its ventral surface; CL cephalothorax length; IML metatarsus I length; ITarL tarsus I length. Vilchura gen. nov. (Figs. 1-3) Type species: Vilchura calderoni sp. nov. Etymology: The generic name is a combination of the type locality Vilches and the Greek ura (tail) in reference to the ending of the Diplura, the type genus of the family Dipluridae. Gender is feminine. Diagnosis: Vilchura gen. nov. differs from all other euagrines in having a megaspine on both tibiae I and II (as opposed to only tibia II having clasping structures in other euagrines), and by the short and recurved fovea. It resembles