Corresponding author: Nícolas Eugenio de Vasconcelos Saraiva ( nicools.eugenio@gmail.com ) Academic editor: Lorenzo Prendini
© 2021 Nícolas Eugenio de Vasconcelos Saraiva, Marcos Ryotaro Hara, Marcio Bernardino DaSilva.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Saraiva NEV, Hara MR, DaSilva MB (2021) Harvestmen in the semiarid: a new genus and three new species of Pachylinae (Opiliones: Gonyleptidae) from Caatinga dry vegetation, with a cladistic analysis. Arthropod Systematics & Phylogeny 79: 485-507. https://doi.org/10.3897/asp.79.e66321
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Abstract
Opiliones are highly diverse in the Neotropics. Because of biological constraints, most harvestmen communities are associated with humid forests, exhibiting a high species diversity and endemism in these habitats. Drier formations, such as the Caatinga biome in northeastern Brazil, are less diverse and still considered under-sampled for the order. This study represents an effort to examine the aforementioned diversity by describing a new Gonyleptidae genus, Sertaneja gen. nov., comprising two new species from Ceará state, Sertaneja bicuspidata sp. nov. and Sertaneja crassitibialis sp. nov., and one new species from Rio Grande do Norte state, Sertaneja falcata sp. nov. A morphological cladistic analysis consisting of 20 terminals and 72 characters was performed to evaluate monophyly of the new genus and relate it to other Gonyleptidae. The analysis resulted in a single most parsimonious tree, corroborating Sertaneja gen. nov. monophyly and relatedness to Gyndoides springmanni Soares & Soares, 1947, which in turn is the sister group to the DRMN clade. Taking into account the morphological traits and phylogenetic placement of Sertaneja gen. nov., we chose to place the new genus in Pachylinae despite its polyphyletic status, given that the Sertaneja gen. nov. clade is closely related to one of the Brazilian Pachylinae lineage. A resolution to the Pachylinae conundrum is needed to further explain the subfamily intricacies. Future research requires a larger scope, but currently, based on the new genus monophyly, support, and relatedness, we formally propose its creation and hope to shed light on the possible evolutionary scenarios for the subfamily.
Arachnida, Grassatores, Neotropics, phylogeny, upland forest
The high species diversity in the Neotropics is well documented for many taxa, and harvestmen are no exception, with many studies describing their abundance and diversity in Neotropical rainforests (
Dry forests and open vegetation biomes (e.g., Caatinga and Cerrado) are less diverse compared to humid forests (
One of the most under-sampled and enigmatic harvestmen groups in the Caatinga region is the Pachylinae, the largest subfamily in Gonyleptidae, with slightly more than 300 registered species (Kury et al. 2001). This subfamily is not a monophyletic group (
The suspicion of Pachylinae polyphyly could be traced back at least 20 years (
In the present paper, we describe a new Pachylinae genus for the northern Caatinga region from Ceará and Rio Grande do Norte states, comprising three new species, based on external morphological characters. We also provide a phylogeny with representatives of some of the main Pachylinae lineages, aiming to shed light on the intricate history of the Caatinga’s harvestmen diversity, which has been barely explored.
Description of the external morphology, topological terms of appendages, mensuration, meristics, genital preparation, and examination mainly follows
External morphology examination was conducted using a stereomicroscope Leica M205C. Penial examination and illustrations were performed using a Zeiss Primo Star binocular microscope fixed with a photo camera and the software ZEN 2 Lite Blue Edition (Zeiss, Germany). Illustration of the external morphology and penis were made in the vector graphics editor Inkscape v. 0.92 (https://inkscape.org), based on a focus-stacked image taken using the Leica stereo microscope associated with the software Leica Application Suite v. 4.2 (Leica Microsystems, Germany). Scanning electron micrographs were obtained using Shimadzu’s SSX-550-SUPERSCAN from the Laboratório de Ensaios de Materiais of the Centro de Tecnologias do Gás e Energias Renováveis, Rio Grande do Norte, Brazil. The material was prepared following the methodology of
The generic characters are not repeated in the species descriptions. Specific descriptions are based only on the male holotype. Females and other described specimens (variation) are stated in separate sections of the description and are solely based on characters that differ from the holotype. Setiferous tubercles (i = small, I = large) of the pedipalp, are described from basal to apical order. All measurements are in millimeters.
Every specimen described here is deposited at the Coleção de Miriápodes e Aracnídeos da Universidade Federal da Paraíba, João Pessoa, Brazil (
All specimens used in the phylogenetic analysis came from loans from Coleção de Aracnídeos e Miriápodes da Universidade Federal da Paraíba (
List of the species and their respective voucher information, used as outgroup taxa in the cladistic analysis. — Abbreviations: s.s. = sensu stricto; s.l. = sensu lato.
Family | Subfamily | Species | Locality | Depository |
Stygnidae | Stygninae | Pickeliana pickeli Mello-Leitão, 1932 | Brazil, São Vicente Férrer – PE |
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Manaosbiidae | Manaosbiinae | Saramacia lucasae (Jim and Soares, 1991) | Brazil, Porto Velho – RO, Abunã |
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Cranaidae | Phareicranainae | Phareicranaus manaura (Pinto-da-Rocha, 1994) | Brazil, Manaus – AM, Fazenda UFAM |
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Gonyleptidae | Heteropachylinae | Pseudopucrolia discrepans (Roewer, 1943) | Brazil, Caaporã – PB |
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Gonyleptidae | Goniosomatinae | Heteromitobates inscriptus (Mello-Leitão, 1922) | Brazil, Caraguatatuba – SP, base do Morro S. Antônio |
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Gonyleptidae | Gonyleptinae | Gonyleptes horridus Kirby, 1818 | Brazil, Guapimirim – RJ |
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Gonyleptidae | Gonyleptinae | Parapachyloides uncinatus (Sørensen, 1879) | Paraguay, San Pedro, Liberacion |
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Gonyleptidae | Pachylinae s.s. | Pachylus chilensis (Gray, 1833) | Chile, Parque Nacional La Camapana |
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Gonyleptidae | Pachylinae s.s. | Acanthopachylus aculeatus (Kirby, 1819) | Brazil, Porto Alegre – RS, Ponta Grossa |
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Gonyleptidae | Pachylinae s.s. | Acanthoprocta pustulata Loman, 1899 | Chile, Araucania, Parque Nacional Nahuelbuta |
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Gonyleptidae | Mitobatinae | Longiperna kuryi Pinto-da-Rocha and Bragagnolo, 2010 | Brazil, Bertioga – SP, trilha descendo rio Itapanhaú |
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Gonyleptidae | Roeweriinae | Roeweria bittencourti Mello-Leitão, 1923 | Brazil, Ilhota – SC, Parque Botânico Morro do Báu |
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Gonyleptidae | Roeweriinae | Roeweria virescens (Mello-Leitão, 1940) | Brazil, São Miguel Arcanjo – SP, Parque da Onça Parda |
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Gonyleptidae | Neopachylinae | Pachylobos longicornis (Mello-Leitão, 1922) | Brazil, Cubatão – SP, COPEBRAS, trilha Grande Fenda 1 |
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Gonyleptidae | Pachylinae s.l. | Eusarcus nigrimaculatus Mello-Leitão, 1924 | Brazil, Rio de Janeiro – RJ, Floresta da Tijuca |
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Gonyleptidae | Pachylinae s.l. | Discocyrtus fenax Kury, Pinto-da-Rocha and Carvalho, 2018 | Brazil, Blumenau – SC, Parque Natural Municipal Nascentes do Garcia |
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Gonyleptidae | Pachylinae s.l. | Gyndoides springmanni Soares and Soares, 1947 | Brazil, Florianópolis – SC, Ilha do Francês |
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The analysis included a total of 72 morphological characters, including five related to the ocularium, 17 to the dorsal scute, three to free tergites, one to chelicerae, one to pedipalps, 31 to leg IV, and 14 to the penis. Characters were mainly based on
The phylogenetic parsimony analysis was performed using TNT v. 1.5 (
Visualization, character evolution analysis, and optimization were performed using the software Winclada v. 1.00.08 (
Morphology: DS dorsal scute; DSL dorsal scute length; DSW dorsal scute maximum width; LI leg I; LII leg II; LIII leg III; LIV leg IV; VP ventral plate; MS A group A macrosetae; MS B group B macrosetae; MS C group C macrosetae; MS D group D macrosetae; MS E group E macrosetae.
Repositories (all in Brazil):
Others: SEM scanning electron microscopy.
Character and states used in the cladistic analysis of Sertaneja gen. nov. Taxon and character states matrix is included in the Supplementary Material File 1.
1 Ocularium type: (0) divided (
2 Undivided ocularium width in dorsal view: (0) width at least 2 × the length (
3 Ocularium dorsal armature: (0) paramedian pair (Figs
4 Ocularium dorsal pair armature length: (0) at least the ocularium height (Figs
5 Ocularium height in relation to eye: (0) low, ca. 1 × the eye diameter; (1) medium, up to 1.5 × the eye diameter; (2) high, at least 2 × the eye diameter (Figs
6 Number of pairs of ozopores openings: (0) one; (1) two.
7 Type of DS γ: (0) γR (
8 DS anterior margin: (0) smooth; (1) bearing a pair or row of distinct projections.
9 Type of DS anterior margin armature: (0) paralateral high spines (
10 DS lateral margin ornamentation: (0) with external row of distinct tubercles; (1) without external row of distinct tubercles.
11 Size of tubercles in the external row of the DS lateral margin: (0) equally sized; (1) slightly increasing in size posteriorly throughout the row (Fig.
12 DS posterior margin integumentary ornamentation: (0) with row of equally sized tubercles throughout the entire margin; (1) with single median apophysis (
13 DS number of areas: (0) three; (1) four.
14 Scute areas general tuberculation aspect: (0) symmetrical with proportional height and length; (1) flat and spread.
15 Scute area I, armature: (0) with paramedian pair of distinct projections; (1) without paramedian pair of distinct projections.
16 Scute area I, distinct paramedian projection type: (0) conical spines (
17 Scute area I, paramedian tubercles position: (0) placed approximately in the center of each half of scute area I; (1) placed close to the median longitudinal groove (Fig.
18 Scute area II, armature: (0) with paramedian pair of distinct projections (Fig.
19 Scute area III, armature: (0) with paramedian pair of distinct projections; (1) without paramedian pair of distinct projections.
20 Scute area III, type of paramedian pair of distinct projections: (0) pair of straight, high spines (
21 Median longitudinal division on scute area IV: (0) absent; (1) present.
22 Scute area IV, armature: (0) without paramedian pair of distinct projections; (1) with paramedian pair of distinct projections (Fig.
23 Free tergite I, type of integumentary ornamentation: (0) with row of equally sized tubercles; (1) with single, median apophysis (
24 Free tergite II, paramedian pair of projection: (0) absent; (1) present.
25 Free tergite III, paramedian pair of projection: (0) absent; (1) present.
26 Chelicerae, segment I posterior face: (0) with projections; (1) without projections.
27 Pedipalp femur, mesal apical seta: (0) absent; (1) present (Figs
28 Male coxae IV and coxae I–III width ratio in situ, in dorsal view: (0) coxae IV as wide as coxae I–III; (1) coxae IV up to 2 × wider than coxae I–III (Figs
29 Male coxa IV length compared to posterior margin of the stigmatic sternite in situ, ventral view: (0) not surpassing it (
30 Male coxa IV dorso-lateral face, integumentary ornamentation: (0) present (Figs
31 Male coxa IV, integumentary ornamentation density: (0) low, ≤ 4 tubercles; (1) medium, > four, ≤ 13 tubercles; (2) high, > 13 (Figs
32 Male coxa IV, prodorsal apical apophysis, type: (0) slender spine (
33 Male coxa IV, prodorsal apical apophysis, length: (0) very small, similar to the eye diameter (
34 Male coxa IV, prodorsal apical apophysis, insertion angle in relation to body medial axis: (0) almost transversal (
35 Male coxa IV, retro-lateral projection: (0) absent; (1) tubercle like, height comparable to width; (2) robust, much higher than wider (Fig.
36 Male coxa IV, retro-lateral robust projection, number of branches: (0) only one (Fig.
37 Male trochanter IV, shape in dorsal view: (0) as long as wide (
38 Male trochanter IV, prolateral central apophysis: (0) absent (
39 Male trochanter IV, proapical projection: (0) absent; (1) tubercle (Fig.
40 Male trochanter IV, proapical apophysis, size: (0) short, ≤1/2 the trochanter length (
41 Male trochanter IV, retro-lateral central conical apophysis: (0) absent; (1) present (Fig.
42 Male trochanter IV, retro-apical projection: (0) absent (
43 Male femur IV and DS length comparison: (0) less or equal to DS; (1) slightly longer than DS; (2) at least 2 × longer than DS. — Treated as ordered.
44 Male femur IV, lateral curvature in relation to trochanter IV main axis: (0) straight, ca. straight angle; (1) slightly arched, ca. obtuse angle; (2) very arched, ca. acute angle. — Treated as ordered.
45 Male femur IV, retro-basal projection: (0) absent; (1) present.
46 Male femur IV, retro-basal projection, type: (0) conical tubercle, slightly larger than the ones covering the podomere surface; (1) large apophysis (Ázara & Ferreira 2018: fig. 28c).
47 Male femur IV, centro-dorsal projection: (0) absent; (1) present.
48 Male femur IV, centro-dorsal projection, curvature: (0) straight; (1) curved retrolaterally.
49 Male femur IV, medio-apical dorsal projection: (0) absent; (1) present.
50 Male femur IV, prodorsal apical distinct projection: (0) absent; (1) present.
51 Male femur IV, prodorsal apical distinct projection, shape: (0) slender spine with tapered apex (
52 Male femur IV, retro-dorsal apical distinct projection: (0) absent; (1) present.
53 Male femur IV, ventro-apical distinct projections, type: (0) tubercles; (1) spines (Figs
54 Male patella IV, dorsal face ornamentation: (0) a pair of paralateral apical spines (
55 Male patella IV, ventral face ornamentation: (0) granule-like projections (
56 Male tibia IV, retro-ventral row, type of integumentary ornamentation: (0) similar sized tubercles; (1) tubercles that increase in size posteriorly (Figs
57 Male tibia IV, ventro-apical armature: (0) tubercles; (1) spines; (2) apophyses. — Treated as ordered.
58 Male tarsal process on legs III–IV: (0) vestigial, setae-like (
59 Penis glans ventral process: (0) absent (Figs
60 Penis glans, ventral process, stem: (0) absent (
61 Ventral process, apex shape: (0) as a triangle shaped tongue with fringes (
62 Dorsal process of glans: (0) present (
63 Penis VP, apical margin, shape: (0) straight or roughly straight (Figs
64 Penis VP, basal lobes in dorsal view, shape: (0) indistinct from VP outline; (1) laterally projected, as long or slightly longer than distal part of VP (
65 Stylus apex, trichomes: (0) absent; (1) present.
66 Stylus apex, trichomes, density: (0) low, few sparse (Figs
67 Stylus apex, winglet like projections: (0) without those projections; (1) with a dorsal, single projection (Figs
68 Penis VP, MS A arrangement: (0) single row (
69 Penis VP, MS C shape: (0) robust, not twisted (Figs
70 Penis VP, MS C arrangement: (0) clustered and equally spaced (Figs
71 Penis VP, MS D quantity: (0) one pair; (1) two pairs.
72 Penis, podium position relative to MS insertion points: (0) placed basally, not reaching MS A/B (
The implied weighting analysis retrieved a single most parsimonious tree for each fit interval, but the most stable trees (L = 240; CI = 0.43; RI = 0.63), according to the SPR distance and distortion coefficient similarity matrices, were found from the fifth to the eleventh intervals at K values of 2.496, 3, 3.659, 4.558, 5.857, 7.898 and 11.571, respectively (Table
Summary of the results from the
K | Steps | Nº of trees | Fit | DC | SPR | |
k1 | 1.286 | 244 | 1 | 36.005 | 0.871427 | 0.80586 |
k2 | 1.509 | 242 | 1 | 33.800 | 0.963156 | 0.93531 |
k3 | 1.776 | 242 | 1 | 31.523 | 0.963156 | 0.93531 |
k4 | 2.098 | 242 | 1 | 29.174 | 0.963156 | 0.93531 |
k5 | 2.496 | 240 | 1 | 26.737 | 0.980001 | 0.96471 |
k6 | 3.000 | 240 | 1 | 24.192 | 0.980001 | 0.96471 |
k7 | 3.659 | 240 | 1 | 21.537 | 0.980001 | 0.96471 |
k8 | 4.558 | 240 | 1 | 18.757 | 0.980001 | 0.96471 |
k9 | 5.857 | 240 | 1 | 15.830 | 0.980001 | 0.96471 |
k10 | 7.898 | 240 | 1 | 12.732 | 0.980001 | 0.96471 |
k11 | 11.571 | 240 | 1 | 9.432 | 0.980001 | 0.96471 |
All three new species were recovered as a monophyletic group closely related to G. springmanni. The clade G. springmanni+ is supported by three exclusive synapomorphies: (i) scute area I with a pair of slightly prominent tubercles placed near the median groove [17(1)]; (ii) scute area III bearing a pair of paramedian spines curved posteriorly [20(2)]; and (iii) scute area IV with a pair of paramedian tubercles slightly more prominent than the surrounding ones [22(1)]. Despite the new genus being sister taxa to G. springmanni, the former’s penial structure differs considerably, being characterized by a rectangular VP, particular macrosetae disposition, stylus morphology, and the absence of a ventral process of the glans. The G. springmanni+ clade, in turn, is a sister group to representatives that could be related to that which
The new genus is supported by 10 synapomorphies of which two are exclusive: (i) external row of tubercles on the DS lateral margin slightly increasing in size posteriorly [11(1)], and (ii) MS A in a clustered arrangement [68(1)] (Fig.
Most parsimonious and stable tree topology retrieved under implied weighting trough
Gonyleptidae Sundevall, 1833
Pachylinae Sørensen, 1884
Sertaneja gen. nov. resembles Gyndoides because of the ocularium armature (despite being variable in Sertaneja), four scute areas, a pair of paramedian spines on scute area II (except S. falcata sp. nov.) and unarmed free tergites. Sertaneja gen. nov. differs from Gyndoides Mello-Leitão, 1927a by: (i) the lateral margin of DS with an external row of tubercles slightly increasing in size posteriorly, (ii) presence of the mesal apical seta on the pedipalp femur (Figs
Sertaneja bicuspidata sp. nov. (A, C–G) Male holotype (
DS gamma (γ) to alpha (α) shaped (Figs
S. bicupidata sp. nov., S. crassitibialis sp. nov., and S. falcata sp. nov.
S. bicuspidata sp. nov.
‘Sertaneja’ is a Brazilian adjective (fem.) that refers to a woman who lives in the Sertão regions in rural communities often in harsh survival conditions. Sertão is the largest sub-region of Brazilian Northeast characterized by dry climates and Caatinga vegetation.
1 | Ocularium with a single robust apical spine (Fig. |
S. crassitibialis sp. nov. |
1’ | Ocularium with a pair of apical spines (Figs |
2 |
2 | Body surface densely tuberculate (Fig. |
S. bicuspidata sp. nov. |
2’ | Body surface sparsely tuberculate (Fig. |
S. falcata sp. nov. |
BRAZIL, Ceará: Ubajara, Parque Nacional de Ubajara.
Holotype. BRAZIL. Ceará: Ubajara PARNA de Ubajara, Rio Gameleira, elev. 840 m, 27.i.2014, DaSilva M.B. Saraiva N.E.V. and Sampaio C., ♂ (
This species can be distinguished from the other species of the genus by the denser tuberculation of the body surface (Fig.
Holotype MALE (
FEMALE (
Males (n = 4): Measurements: DSL: 4.33–4.86; DSW: 4.47–4.97; LI: 8.52–9.13; LII: 15.60–17.62; LIII: 10.78–12.30; LIV: 14.25–15.83. Dorsum: Ocularium spines as tall as, or slightly taller than the ocularium. Scute area III paramedian pair of spines medium to large, length reaching backwards up to halfway of scute area IV. Pedipalps: Pedipalpal setation: tibial mesal IiIi, lateral IiIi/i-Ii; tarsal mesal IIi/IIii, lateral IiIi/Iii. Legs: Minor males, compared to major males as the holotype, with less developed armature on scute area III and weaker armature of legs: coxa IV narrower and shorter, prodorsal apical and retro-apical apophyses smaller and slender (on major males prodorsal apical apophysis shorter projection can be acuminate); trochanter III retro-lateral projection reduced; trochanter IV all apophyses smaller; femur III prolateral and ventral rows of tubercles less developed, with smaller proapical tubercles; femur IV pro- and ventro-apical tubercles smaller; tibia IV proventral and retro-ventral rows reduced. Tarsal count: 6, 9–10, 6, 6.
‘Bicuspidata’ is a Latin adjective (adj. perf. part., nom. fem.) that refers to the diagnostic bifid apophysis of male coxa IV in this species.
Caatinga shrublands and dry forests of northern interior Ceará and Brejos de Altitude humid montane forests of Ibiapaba mountains.
BRAZIL, Ceará: Quixadá, Serra do Urucu, Santuário Nossa Senhora Imaculada Rainha do Sertão.
Holotype. BRAZIL. Ceará: Quixadá, Serra do Urucu, Santuário Nossa Senhora Imaculada Rainha do Sertão, elev. 344 m, 19.iv.2014, DaSilva M.B. and Saraiva N.E.V., ♂ (
Differs from the other species by the lower density of tubercles and armature (Fig.
Sertaneja crassitibialis sp. nov. (A, C–G) Male holotype (
Holotype MALE (
FEMALE (
Males (n = 3): Measurements: DSL: 4.91–4.99; DSW: 4.67–4.90; LI: 8.98–10.08; LII: 15.31–16.17; LIII: 11.58–12.44; LIV: 16.14–16.34. Dorsum: Ocularium spine more, or less acute. DS lateral margin external row of rounded to acuminate tubercles, becoming almost spine-like. Scute area II with tubercles placed near the lateral margins. Legs: Tibia IV retro-ventral apical spine single or bifid. Tarsal counts: 6, 8–9, 6, 6. Females (n = 5): Measurements: DSL: 4.61–4.75; DSW: 4.20–4.55; LI: 8.56–9.45; LII: 13.93–15.97; LIII: 10.25–11.28; LIV: 14.80–15.52. Pedipalps: Pedipalp tibial setation: mesal IiIi/IIi, lateral IiIi; tarsal setation: mesal IIi, lateral IiIi/Iiii. Legs: Femur IV proventral row of tubercles slightly enlarged or not. Patella IV with or without prodorsal apical projection. Tarsal counts: 5–6, 8–9, 6, 6.
‘Crassi-’ is a Greek adjective, meaning thick, and ‘tibia’ is the Latin noun meaning the podomere; combined to ‘crassitibia’ (nom. sing. fem.) in reference to the diagnostic male tibia IV of the species.
Brejos de Altitude humid montane forests of Ibiapaba mountains and Caatinga shrublands and dry forests of northern interior Ceará.
BRAZIL, Rio Grande do Norte: Portalegre, Cachoeira do Pinga.
Holotype. BRAZIL. Rio Grande do Norte: Portalegre, Cachoeira do Pinga, encosta da serra, elev. 431 m, 23–24.iv.2014, DaSilva M.B. and Saraiva N.E.V., ♂ (
Distinguished from other species by the presence of a pair of slightly enlarged paramedian tubercles on scute area III (Fig.
Sertaneja falcata sp. nov. (A, C–G) Male holotype (
Holotype MALE (
FEMALE (
Males (n = 6): Measurements: DSL 4.43–4.66; DSW 4.84–5.06; LI 8.91–10.21; LII 17.52–19.48; LIII 12.24–13.08; LIV 16.19–17.51. Dorsum: Front margin with or without tubercles. Ocularium with parallel or diverging spines, inclination of these ranging from near-horizontal to vertical. Pedipalps: Femur external lateral row with 2–3 sub-apical tubercles. Legs: Femur IV dorso-apical spines with similar size to retro-lateral largest and strongly curved upwards; retro-lateral central conical apophyses sometimes with an additional apophysis of half the height of the remaining apophyses in the middle; apical half of proventral row bearing small tubercles alternated with large ones. Tarsal counts: 6, 10–12, 6, 4–6. Females (n = 2): Measurements: DSL 4.13–4.27; DSW 4.32–4.46; LI 8.83–8.84; LII 16.16–16.57; LIII 10.93–11.62; LIV 10.09. Pedipalps: Pedipalp tibial setation: mesal IiIi, lateral IiIi. Tarsal setation: mesal IIi, lateral IiIi/IiIii. Legs: Tarsal counts: 6, 9–10, 6, 6.
‘Falcata’ is a Latin adjective (adj. nom. fem.) that means sickle-shaped and refers to the diagnostic retro-apical apophysis of male coxa IV of the species.
Known only from type locality. Caatinga dry forest of tableland slopes of interior Rio Grande do Norte.
These three new species represent a great discovery for Brazilian semiarid diversity and Gonyleptidae phylogeny. Taxonomically, we could assign the three new species to Gyndoides based on their apparent morphological similarity. However, the undivided scute area IV and male genitalia homogeneity of the three new species differed considerably from that of Gyndoides by the (i) lack of a glans ventral process; (ii) mostly rectangular and long ventral plate; and (iii) amount and placement of the MS. Additionally, the three new species inhabit northeastern Brazil in the Ceará and Rio Grande do Norte states, approximately 2,700 km from where Gyndoides species are found (Fig.
From a historical perspective (namely, the Roewerian system) and intuitively, based solely on the overall morphology (except for the penile one) it would be plausible to propose three different genera based on such external variation. But as thoroughly discussed (
Gyndoides springmanni+ is the sister group to the clade that is equivalent to DRMN in the analyses (Figs
As a side note, we justify why we did not assign the three new species to other genera deemed close to Gyndoides according to
In the present analyses, Pachylinae s.s., represented by A. pustulata+, was also retrieved, and is supported by 17 synapomorphies with relative Bremer support of 52 (Figs
Our goal was not to present a Pachylinae s.l. phylogeny, which would certainly be a large, exhaustive, and meticulous task. Currently, the subfamily Pachylinae is one of the greatest challenges in Gonyleptidae systematics because it is species-rich, polyphyletic (
The semiarid region of northeastern Brazil contains 29 Laniatores species north of the São Francisco River, which is considered a major geographical barrier in the region (
The high diversity and endemicity rates of the harvestmen in the northeastern region of coastal Atlantic Forest, when compared to interior drier formations, are generally associated to intrinsic physiological traits, such as the group propensity for rapid dehydration, as well as behavior attributes (
Sertaneja gen. nov. is the first Gonyleptidae recorded from semiarid vegetation, except for some cavernicolous species from Bahia, and was an unexpected find because harvestmen are often associated with humid environments. Through the cladistic analysis, we were able to evaluate the monophyly of the new genus and its proximity to some key, recently revised, Pachylinae s.l. groups.
These new findings help shed light on the potential diversity of the order in northeastern Brazil, which currently is the leading country in the number of registered harvestmen species, with slightly more than 1000 according to
The authors would like to thank Dr. Ricardo Pinto da Rocha (