Further dismemberment of Discocyrtus with description of a new Amazonian genus and a new subfamily of Gonyleptidae (Opiliones, Laniatores)

A group of Amazonian harvestmen is recognized and described as Amazochroma gen. nov. This taxon includes Discocyrtus carvalhoi Mello-Leitão, 1941 (type species), the only species of Discocyrtus previously thought to occur in Amazonia, and Amazochroma pedroi gen. et sp. nov., described here from the Brazilian states of Acre and Rondônia. New records are added for Amazochroma carvalhoi gen. et comb. nov, expanding its distribution from the Brazilian state of Mato Grosso northwards also to Pará and Amazonas in Brazil and additionally French Guiana and Suriname. Diagnostic features of Amazochroma gen. nov. include: trichromatic pattern of legs, dry marks on the dorsal scutum and base of legs and diastema in the row of macrosetae C of the penis ventral plate. A morphological maximum parsimony analysis (1022 scorings; 16 taxa; 64 characters) is performed to test whether Amazochroma gen. nov. is a member of Discocyrtus and if the traditional allocation of Discocyrtus in Pachylinae is defendable. A clade is retrieved containing three groups: (1) Mitobatinae, (2) Discocyrtus and (3) a clade containing Amazochroma gen. nov., Discocyrtanus and Roeweria, here described as a new subfamily of Gonyleptidae – Roeweriinae subfam. nov. Discocyrtanus Roewer, 1929 and Roeweria Mello-Leitão, 1923 are accordingly here transferred from Pachylinae to Roeweriinae subfam. nov.


Introduction
Discocyrtus Holmberg, 1878 is one of the most diverse genera of Laniatores harvestmen, counting 67 valid species (Kury 2003(Kury , 2008Kury & Carvalho 2016). In the last few years, the authors have been conducting a project at the Museu Nacional, Universidade Federal do Rio de Janeiro, aiming to defi ne the boundaries of this genus.
The current diagnosis of Discocyrtus dates from Soares & Soares (1954: 245), which in turn directly refl ects the "Roewerian" classifi cation system (as nicknamed by Henriksen 1932). The use of formulaic meristic characters such as tarsal counts, and armature of scutal areas and free tergites is not capable, alone, of satisfactorily discriminating among the increasing discovered diversity of genera in Gonyleptidae. Therefore, the current composition of Discocyrtus is predictably heterogeneous.
The vast majority of species of Discocyrtus (58 valid species) has been described in the fi rst half of the 20th century, with the meager addition of two species later in that century (by Soares 1970 andTavares 1981). After a long stagnant hiatus, an isolated cavernicolous species was described by Kury (2008).
The terminology for the chaetotaxy of the penis ventral plate follows Kury & Villarreal (2015) for the macrosetae and Kury (2016) for the microsetae. The term mesotergum (Mello-Leitão 1930) refers to the roughly subrectangular region of the dorsal scutum formed by areas I to IV and circumscribed anteriorly by the scutal groove, laterally by the lateral margins and posteriorly by the area V (posterior margin of scutum). The term dry mark ("mancha seca" Kury 1991 and"dry-mark" Kury in DaSilva &Gnaspini 2010) refers to the more external serose layer of the cuticle that forms powdery patterns in the living animal or when it dries up after removed from preserving fl uid. In the diagnoses, taxa are compared to Discocyrtus testudineus representing Discocyrtus (sensu stricto), because Discocyrtus is notably a heterogeneous assemblage.
Biogeographical units used here are from the WWF Terrestrial Eco-regions of the World (names starting with "NT"; Olson et al. 2001) and Morrone's regionalization of the Neotropics ("provinces"; Morrone 2014). They are indicated by colored background areas on the maps (Figs 2, 11) based on a shapefi le created by Löwenberg-Neto (2014).
Scanning electron microscopy was carried out with a JEOL JSM-6390LV at the Center for Scanning Electron Microscopy of Museu Nacional/UFRJ. All measurements are in millimeters (mm). = dorso-lateral, subdistal small setae of VP E1-E2 = ventro-distal macrosetae of VP Tarsal formula: numbers of tarsomeres in tarsus I to IV (Table 4), when an individual count is given, are ordered from left to right side (fi gures in parentheses denote number of tarsomeres only in the distitarsi I-II).

Choice of terminals
The primary targets of the analysis are both of the species here included in Amazochroma gen. nov. To test their monophyly we have used putative (pre-analysis suspects) close relatives such as Discocyrtanus and Roeweria (each represented by two species). We also used as ingroups the Mitobatinae and Discocyrtus s. str. (each represented by two species, including the type species). All of these terminals have at a given point been considered to be either inside Discocyrtus or Mitobatinae. Including representatives of all subfamilies of Gonyleptidae would unnecessarily burden the analysis, so we chose representatives of Pachylinae (the subfamily where Discocyrtus is formally placed, represented here by four species -Acanthopachylus aculeatus (Kirby, 1819), Anoplogynus nasutus Piza, 1938, Neopachylus imaguirei Soares & Soares, 1947 and Pachylus chilensis (Gray, 1833)), and the paradigmatic K92 (Gonyleptes horridus Kirby, 1819). The prime outgroup to root the analysis was Ampycus telifer (Butler, 1873), representing the basal Gonyleptidae or sometimes even considered a non-gonyleptid Gonyleptoidea, the Ampycinae.

Maximum parsimony (MP) analysis
The character states were tabulated in a matrix using Morphobank 3.0 (O'Leary & Kaufman 2012). The annotated list of characters is in Table 1. The matrix of characters states and terminals (1052 scorings; 16 taxa; 66 characters) is in Table 2. Trees were searched in TNT (Goloboff et al. 2008b) using parsimony under implied weights (Goloboff 1993) with the traditional search algorithm and TBR branch-swapping. Space was allocated for 10000 trees in memory and 10 replicates with 10000 trees each were carried out. In this study, we used a TNT script (setk.run) written by Salvador Arias to calculate the value for the concavity constant k which best matches our data (for details see Goloboff et al. 2008a). The script yielded a value of k = 1.992188 for our data set, which was then employed. The stability of clades was estimated by Absolute symmetric frequencies (SFq) resampling values (10000 replicates, cut = 50, change probability = 33) using TNT (Goloboff et al. 2003). As a parameter of data substantiation, absolute Bremer (or branch) support, aka "decay index" (Bremer 1994) was used, also calculated by TNT. Both bootstrap and Bremer values are shown in Fig. 4.

Results of the analysis
As a result of this analysis, a new genus and a new subfamily are proposed. The two species of Amazochroma gen. nov. (Fig. 1) are medium to large gonyleptids, with a tricolored pattern (formed by black, red and strong yellow) throughout the length of the legs, dry marks extensively covering the dorsal scutum, coxae and trochanters, and a well-developed armature on the ocularium. They are distributed in the Amazonian Forest of Brazil, Suriname and French Guiana (Fig. 2). The clade formed by Amazochroma gen. nov., Discocyrtanus and Roeweria is here described as Roeweriinae subfam. nov., which is part of a more inclusive group (here nicknamed DRMN) also including the Mitobatinae, Neopachylus Roewer, 1913 and Discocyrtus.
TNT yielded a single maximum fi t (= 15.073246) tree (characters mapped in Fig. 3, and summary of larger groups in Fig. 4). When viewed in WinClada, which is optimized in terms of steps (equal weights), instead of fi t, they would have been 162 steps long, with CI = 63 and RI = 73. The two Amazonian species treated here form a clade (described below as the genus Amazochroma gen. nov.). This clade is both 1. Dorsal scutum, lateral margins, color 0 dark brown, matching the mesotergum 1 yellow, with brown reticulum, matching the mesotergum 2 light brown, reticulated, contrasting with mesotergum, which has predominant uniform dark brown background 2. Legs (most markedly III-IV), trichromatic striped pattern in yellow, black and red 0 absent 1 present 3. Body and appendages, dry marks 0 absent 1 present 4. Body and appendages, dry marks, aspect 0 restricted to tip of tubercles of dorsal scutum 1 forming cruciform pattern on dorsal scutum 2 around the tubercles all over the dorsal scutum 5. Dorsal scutum of male, outline, shape 0 alpha-shape 1 gamma-shape 2 lambda-shape 3 gamma triangular shape 4 kappa-shape 6. Ocularium, height 0 low 1 elevated 7. Ocularium, armature, type 0 pair of paramedian blunt spines tilted forwards 1 single spine or acuminate tubercle 2 one pair of very small tubercles 3 one pair of highly divergent acuminate spines 8. Ocularium, armature, inclination in lateral view in relation to body axis 0 erect (90 degrees) 1 slightly inclined anteriorly 2 greatly inclined anteriorly 9. Ocularium, form in anterior view 0 convex 1 saddle-shaped, with a median depression 2 subrectangular 10. Ocularium, position on the carapace in relationship to the insertion of legs 0 at second pair of legs 1 between the second and third pairs of legs 2 at third pair of legs  (Bremer = 4). The sister group of Amazochroma gen. nov. is the recently revalidated Discocyrtanus. The two terminals of Discocyrtanus do form a clade, but in itself this is not proof of the monophyly of this genus, because our analysis did not include three out of the fi ve species. The clade formed by Amazochroma gen. nov. and Discocyrtanus is stable and well supported (95/5). This clade is in turn a sister group of Roeweria, forming a clade that we describe below as Roeweriinae subfam. nov. (pink clade). The Roeweriinae subfam. nov. are stable and well-supported (98/7). Our analysis also convincingly shows that neither Discocyrtus (blue clade), nor Neopachylus, nor ex-Discocyrtus (now in Discocyrtanus and Roeweria) share a special similarity with the Pachylinae (red clade), instead being more closely related to the Mitobatinae (green clade). We chose to convey this similarity by creating the denomination DRMN (yellow clade, including Discocyrtus, Roeweriinae subfam. nov., Mitobatinae and Neopachylus).

Diagnosis
Dry marks either around the tubercles or restricted to their tips, but in both cases all around dorsal scutum (only in Amazochroma gen. nov. and Discocyrtanus, absent in Roeweria; contrasting with Discocyrtus and some Mitobatinae [e.g., in Ischotherus Kury, 1991, Mitobates Sundevall, 1833Neoancistrotus Mello-Leitão, 1927, Promitobates Roewer, 1913, Ruschia Mello-Leitão, 1940 where it is absent and with other Mitobatinae which possess dry marks arranged in broad stripes, often cruciform [e.g., in Discocyrtoides Mello-Leitão, 1923, Longiperna Roewer, 1929. Ocularium convex, with a median depression (contrasting with the convex form without depression in Discocyrtus and Discocyrtoides or rectangular form in Mitobates). Mesotergum divided into 4 areas (same as in Discocyrtus testudineus Holmberg, 1876 and Mitobatinae). Area I with a pair of conspicuous paramedian tubercles (same as D. testudineus, absent in D. crenulatus Roewer, 1913 and Discocyrtoides). Retrodorsal distal apophysis of Cx IV of males with only a main tubercle (absent in Amazochroma pedroi gen. et sp. nov., contrasting the form with a geminated tip present in Discocyrtus and some Mitobatinae). Distal part of the VP of penis forming a trapezium, with an apical minor base (contrasting with a trapezium with an apical major base occurring in Discocyrtus and Discocyrtoides or the M-form of Mitobates). Macrosetae C1-C3 of VP elongate and slender (contrasting with the short and thick form found in Discocyrtus and Mitobatinae). Macrosetae C1-C3 insertion with C3 set widely apart from the other C, forming a diastema (present in Amazochroma gen. nov. and Roeweria, contrasting with all macrosetae C placed distally with subequal intervals between them as found in Discocyrtanus and with macrosetae C placed distally, united as in Discocyrtus and Mitobatinae). Ventral of glans process extremely reduced or absent (contrasting with the presence of a stem and a fl abellum in Discocyrtus and Mitobatinae). Stylus sigmoid, strongly bent to dorsal proximally and overall curved to ventral more distally (present in Amazochroma gen. nov. and Discocyrtanus, contrasting with the C-shape, overall arched to dorsal found in Roeweria and the substraight shape as in Discocyrtus and Mitobatinae). Angle of basal curvature of stylus around 90 degrees (in opposition to form with less than 90 degrees in Discocyrtus and Discocyrtoides or more than 90 degrees in Mitobates). Apical winglets of stylus (present in Amazochroma gen. nov., Discocyrtanus and Roeweria, absent in Discocyrtus and Mitobatinae).

Etymology
From region name Amazonia + the Greek χρῶμα (color), referring to the vivid bands shown by the species, contrasting with the dull color of most Amazonian gonyleptids. Gender neuter.

Diagnosis
Amazochroma gen. nov. has the outline of the male dorsal scutum gamma-shaped (in common with Discocyrtanus and D. testudineus, different from the gamma triangular shape in Roeweria). Ocularium low (in common with Discocyrtanus and Roeweria, contrasting with an elevated present in D. testudineus), with a pair of strong paramedian divergent spines (as in D. testudineus, Discocyrtanus and Roeweria). Legs with trichromatic striped pattern (most markedly III-IV) in strong yellow, red and black (not occurring in Mitobatinae, D. testudineus, Discocyrtanus and Roeweria). Area II with two anterior and six posterior paramedian tubercles (not occurring in Mitobatinae, D. testudineus, Discocyrtanus and Roeweria). Anterior outline of scutal area III only gently arched, not convex penetrating into area II (as in Discocyrtanus and Roeweria, contrasting with an outline strongly arched deeply encased in area II found in D. testudineus). Posterior outline of scutal area III only gently arched, not twice convex  penetrating into area IV (in common with Discocyrtanus and D. testudineus, different from twiceon left and right sides -strongly convex penetrating into area IV found in Roeweria). Tr IV with a prolateral medial apophysis (not occurring in Mitobatinae, D. testudineus, Discocyrtanus and Roeweria). Pa IV without a retroventral row of tubercles (present in Mitobatinae, D. testudineus, Discocyrtanus and Roeweria). Stylus strongly sigmoid (in common with Discocyrtanus, different from C-shaped in Roeweria and the substraight shape in D. testudineus). Stylus with well-marked apical barbed winglets (same as in Discocyrtanus and Roeweria, absent in D. testudineus). Presence of well-developed dry marks encircling the granules and tubercles of dorsal scutum, free tergites and Cx-Tr I-IV (in contrast to presence restricted to tip of tubercles of dorsal scutum in Discocyrtanus and absence in D. testudineus and Roeweria). Legs with trichromatic striped pattern (most markedly III-IV) in strong yellow, red and black (not occurring in D. testudineus, Discocyrtanus and Roeweria). Cx IV of males with prodorsal distal apophysis very strong and substraight, only gently curved to ventral side (extremely curved in Roeweria, slender geniculate in Discocyrtanus and D. testudineus). Macroseta C3 set widely apart from the other C, forming a diastema (as in Roeweria, contrasting with all macrosetae C placed distally, with subequal intervals between them found in Discocyrtanus and macrosetae C placed distally, united as in D. testudineus). Fig. 3. Cladogram depicting proposed external and internal phylogenetic relationships of Roeweriinae subfam. nov., with unambiguous synapomorphies for each clade mapped. This is the single tree obtained by TNT. Small numbers above symbols are the numbers of the characters. Green squares = nonhomoplastic synapomorphies; white circles = homoplastic synapomorphies.

Etymology
Patronymic in honor of Brazilian zoologist Antenor Leitão de Carvalho (1910-1985, who collected the holotype of this species.

Redescription
Holotype (male) MEASUREMENTS. CW 3.3, CL 2.0; AW 6.1, AL 3.6. Leg measurements in Table 3, tarsal counts in Table 4. DORSUM. Dorsal scutum almost as long as wide, abdominal scutum with lateral margins strongly convex, widest at area II and highest at area III (Fig. 5A, D). Carapace with several tubercles on posterior region (Fig. 5A, D). Cheliceral sockets shallow, with a small apophysis in the center. Ocularium elliptical, high, inclined frontwards, placed in middle of carapace, armed with a pair of divergent high spines fused at baseline and inclined frontwards (Fig.5A, C -D). Mesotergum divided into four clearly defi ned areas. Area I divided into left and right halves by median groove. Area II anterior lateral border invading slightly space of area I and posterior lateral border invading the space of area III. AS lateral borders with tubercles on full extent, gradually growing to height of area III. All areas with many tubercles. Area I with a pair of paramedian tubercles higher than the others. Area II with one main transverse row of tubercles, replaced in middle by two pairs (one anterior and one posterior) of moderate-sized tubercles forming a trapezoid. Besides those, several others minor tubercles. Area III with a pair of high paramedian acuminated spines curved backwards, with the base covered by small tubercles (Fig. 5A-B, D). Area IV with horizontal row of 3 highlighted tubercles. Posterior border of dorsal scutum and free tergites with a horizontal row of tubercles with same height as highlighted on area IV.
VENTER. Cx I-III parallel to each other; each with ventral transverse rows of 9-10 setiferous tubercles (Cx I main row with higher and sharper tubercles). Cx IV much larger than the others, directed obliquely. Stigmatic area Y-shaped, clearly sunken relative to distal part of coxa IV. Intercoxal bridges well marked. Stigmata clearly visible. Free sternites and anal operculum each with a transverse row of small tubercles.
LEGS. Tr I-III each with several ventral tubercles. Fe I and II straight. Fe I retrolateral proximal tubercle higher than the others, not forming a spur. Tr I with prodorsal, proventral, retroventral and retrodorsal rows of small tubercles. Fe II with prodorsal, prolateral, proventral, retroventral, retrolateral and retrodorsal rows of small tubercles. Fe II with a small retrodorsal distal tubercle higher than the others, not forming a spur. Tr II with prodorsal, proventral, retroventral and retrodorsal rows of small tubercles. Fe III substraight. Fe III and Ti III with prodorsal, prolateral, retrolateral and retrodorsal rows of small tubercles, with proventral and retroventral rows of tubercles gradually growing to the distal portion. Fe III and Mt III with a well-developed retrodorsal distal spur. Posterior border of Cx IV not reaching longitudinally the posterior border of dorsal scutum. Cx IV with a prolateral apical caniniform apophysis, moderately elongate and a retrodorsal spiniform apophysis (Fig. 5A). Cx IV with prodorsal, prolateral and proventral rows of tubercles. Tr IV prolaterally with three conical apophyses: two proximal, unequal ones and one distal, longer, bifurcated. Tr IV distally and retrolaterally with one spearhead apophysis. Tr IV ventrally with several tubercles along its entire length. Fe IV substraight, curved from the medial region toward dorsal. Fe IV with prodorsal, prolateral, retroventral and retrodorsal rows of small tubercles, dorsal tubercles only in proximal portion (Fig. 5E-H). Fe IV prodorsally (entire length) and retrolaterally (proximal-medial portion) with a row of setiferous tubercles (Fig. 5E-F, H). Fe IV proventrally and retrodorsally with one distal spine forming a spur (Fig. 5E-H). Pa IV covered by tubercles in dorsal view; also with proventral and retroventral rows of three tubercles each. Ti IV with prodorsal, prolateral, proventral, retroventral, retrolateral and retrodorsal rows of tubercles. Ti IV with proventral and retroventral distal spurs. Tarsal counts: 6(3)-6(3)/9(3)-9(3)/7-7/7-7.

VARIATION. Besides the variation in tarsal counts, shown in
Female (MNRJ 8811) CW 4.2, CL 2.7; AW 7.6, AL 4.7. Cx IV with much weaker armature compared to male, main apophysis reduced to a simple spine. Fe IV thinner, less curved and armed when compared to male. Fe IV with fewer spines on distal proventral axis and a retrolateral distal spur.

Remarks
This species was described in Discocyrtus, and never illustrated. In a catalogue of the Pachylinae, Soares & Soares (1954) merely listed the name. Its generic assignment has never been challenged.

Etymology
The species name honors our friend, the arachnologist Pedro Henrique Martins, who collected most of the type series and provided fi ne pictures of this species.

Diagnosis
Carapace with a pair of paramedian larger tubercles, as large as found at paramedian of area I, darker, contrasting with background (absent in A. carvalhoi comb. nov.) (Fig. 7A, D); areas I-III with two higher tubercles next to the median groove (absent in A. carvalhoi comb. nov.) (Fig. 7A); area III with a pair of low, paramedian, rounded tubercles (lower and broader than the pair of high, paramedian, acuminated spines of A. carvalhoi comb. nov.) (Fig. 7B, D); Tr IV prolateral median with an apophysis (not occurring in A. carvalhoi comb. nov.) (Fig. 7A); Fe IV prolaterally and retrolaterally with high spines (instead of spines absent in A. carvalhoi comb. nov.) (Fig. 7F, H).

Description
Male (holotype) CW 3.7, CL 2.4; AW 6.9, AL 3.9. Leg measurements in Table 5, tarsal counts in Table 4. DORSUM. Dorsal scutum almost as long as wide, abdominal scutum with lateral margins strongly convex, widest at area II and highest at area III (Fig. 7A, D). Carapace with several tubercles on posterior region, with a pair of paramedian larger tubercles, darker, contrasting with background (Fig. 7A, D). Cheliceral sockets shallow, with a small apophysis in center. Ocularium elliptical, high, inclined frontwards, placed in middle of carapace, armed with a pair of divergent high spines fused at baseline and inclined frontwards (Fig. 7A, C-D). Mesotergum divided into four clearly defi ned areas. Areas I, III and IV divided into left and right halves by median groove. Area II anterior lateral border invading slightly space of area I and posterior lateral border gently invading space of area III. AS lateral borders with ordinary tubercles on full extent. All areas with several tubercles (darker than background). Area I with a pair of paramedian tubercles higher than the others and two medium tubercles (one anterior and one posterior) highlighted next to median groove. Area II with two medium tubercles (one anterior and one posterior) highlighted next to median groove and two medium tubercles highlighted abreast on horizontal medium. Area III with a pair of low, paramedian, rounded tubercles and two medium tubercles (one anterior and one posterior, about half size of paramedian) highlighted next to median groove ( Fig. 7A-B, D). Area IV with six to eight minor tubercles plus horizontal row of three rounded, larger tubercles on each side. Posterior border of dorsal scutum and free tergites with a horizontal row of rounded tubercles.
VENTER. Cx I-III parallel to each other; each with ventral transverse rows of 6-10 setiferous tubercles (Cx I main row with higher and sharper tubercles). Cx IV much larger than the others, directed obliquely. Stigmatic area Y-shaped, clearly sunken relative to distal part of coxa IV. Intercoxal bridges well marked. Stigmata clearly visible. Free sternites and anal operculum each with one transverse row of small tubercles.
VARIATION. Besides the variation in tarsal counts, shown in Table 4, the minor ("beta") males only show a difference in attenuated armature of Fe IV proventral and retrolateral rows of spines. Distribution and development of tubercles and apophyses in our sample fairly uniform. Female (paratype, MNRJ 9267) CW 4.2, CL 2.5; AW 7.4, AL 4.6. Cx IV with much weaker armature, main apophysis reduced to a simple spine. Fe IV thinner and less curved when compared to that of male. Fe IV with fewer spines on distal proventral axis and a retrolateral distal spur.

Discussion
In the present study, we obtained evidence for a monophyletic group here nicknamed DRMN (that is, Discocyrtus, Roeweriinae subfam. nov., Mitobatinae and Neopachylus; Fig. 4). Inside DRMN we detected for the fi rst time a group formed by "false" Discocyrtus (Amazochroma gen. nov. and Discocyrtanus) and Roeweria (a genus which has wandered through many affi liations), which we described above as the new subfamily Roeweriinae subfam. nov. The parapatric distribution of the genera of Roeweriinae subfam. nov. in South America is illustrated in Figs 2 and 11. Amazochroma gen. nov. occurs in the upper and lower Amazon drainage (provinces Madeira, Pará, Rondônia, Roraima and Xingu-Tapajós, corresponding to various WWF ecoregions of biome 01, Tropical/Subtropical Moist Broadleaf Forests), while Discocyrtanus is basically distributed in the Cerrado Province (Morrone 2014), which corresponds to WWF NT 0704 (Cerrado, belonging to biome 07, Tropical/Subtropical Grasslands, Savannas, Shrublands) but also occurring in fringes of the Morrone's Paraná Forest Province, which is equivalent to ecoregion NT 0150 (Alto Paraná Atlantic Forests). Roeweria is mostly endemic to the Atlantic Province, with a marginal incursion into the Paraná Forest Province.
Discocyrtanus, Discocyrtus, Neopachylus and Roeweria were previously allocated to the nonmonophyletic Pachylinae, but our analysis confi rmed the modern trend of shrinking the circumscription of the Pachylinae to the genera in the most immediate vicinity of Pachylus C.L. Koch, 1839, while the above cited groups are here hypothesized to be closest to the Mitobatinae, a subfamily distributed from the Brazilian Atlantic Forest.
The Mitobatinae gradually specialized into a new ecological niche: they abandoned life in the leaf mold and traded leg armature for elongation, the Cx IV musculature was greatly reduced, losing the typical gonyleptid armature, which even infl uenced the body outline, which changed from pyriform in Discocyrtoides to rectangular in Mitobates. Even the microhabitat was modifi ed, with the exchange of ground substrate for massive boulders on water streams. However, closer study of Mitobatinae (especially the early derivative species) still betrays an obvious connection with Discocyrtus and the like.
Earlier authors have not always understood the relationships of Mitobatinae, ascribing to this subfamily virtually every long-legged species of Grassatores. Yet, short-legged Laniatores such as Discocyrtus and immediately related genera (Fig. 10) have long since been thought to be more closely related to the Mitobatinae than to the Pachylinae. However, a recent analysis (Bragagnolo & Pinto-da-Rocha 2012) placed Discocyrtus testudineus very far away from the Mitobatinae, together with the Caelopyginae, a result at odds with our present concept of DRMN. Mello-Leitão (1923) came up with the concept of the Bourguyiinae, which at one point included Discocyrtoides -and even this name per se betrayed a perception of the proximity with Discocyrtus. Roeweria was originally included in Mitobatinae, one of its species was originally included in Discocyrtus, and one of its synonyms was even synonymized under Discocyrtus, not to mention its synonymy under Discocyrtoides.
More recently, Kury (1991) indicated Discocyrtus as the possible sister-group of the Mitobatinae, and Pinto-da-Rocha et al. (2014) obtained a tree where both Discocyrtus (s. lat.) and Roeweria form a clade with the Mitobatinae. Another interesting possibility raised by molecular studies (Pinto-da-Rocha et al. 2014) is the non-monophyly of the Mitobatinae. At this stage, an increased sampling of nominal Discocyrtus and Mitobatinae is needed to study this hypothesis. That is why we chose here not to ascribe Discocyrtus to any subfamily in Gonyleptidae: an ongoing project is gradually surveying a much denser taxonomic sample of Discocyrtus and other potential disruptors of DRMN monophyly.