Troglorhopalurus Lourenço, Baptista and Giupponi, 2004

Lauren A. Esposito, Humberto Y. Yamaguti, Cláudio A. Souza, Ricardo Pinto-Da-Rocha & Lorenzo Prendini, 2017, Systematic Revision of the Neotropical Club-Tailed Scorpions, Physoctonus, Rhopalurus, and Troglorhopalurus, Revalidation of Heteroctenus, and Descriptions of Two New Genera and Three New Species (Buthidae: Rhopalurusinae), Bulletin of the American Museum of Natural History 415, pp. 1-134 : 116-118

publication ID	https://doi.org/ 10.1206/0003-0090-415.1.1
publication LSID	lsid:zoobank.org:pub:146A0539-0A2C-44CD-986C-8F8A8EB4598C
DOI	https://doi.org/10.5281/zenodo.4610710
persistent identifier	https://treatment.plazi.org/id/8F65ED57-FFBE-B123-38F5-CCC8B21C6ADF
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scientific name	Troglorhopalurus Lourenço, Baptista and Giupponi, 2004
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Troglorhopalurus Lourenço, Baptista and Giupponi, 2004 View in CoL

Figures 1 View FIG. 1 G, H View FIG , 2G, H View FIG , 9 View FIG , 10E View FIG , 11F View FIG , 12D View FIG , 14F View FIG , 15E View FIG , 17F View FIG , 18F View FIG , 19E View FIG , 21K, L View FIG , 22K, L View FIG , 61–63 View FIG View FIG View FIG

Troglorhopalurus translucidus Lourenço et al., 2004 View in CoL , type species by original designation.

Troglorhopalurus Lourenço et al., 2004: 1151– 1156 View in CoL , figs. 1–10; Prendini and Wheeler, 2005: 481, table 10; Volschenk and Prendini, 2008: 236, 249; Prendini et al., 2009: 206, 222; Brazil and Porto, 2010: 57; Ochoa et al., 2010: 17; Ubinski et al., 2016: 122.

Rhopalurus View in CoL (part): Lourenço and Pinto-da- Rocha, 1997: 182–188, 191, figs. 1–3, 5, 7, 9, 11, 14; Kovařík, 1998: 118; Fet and Lowe, 2000: 220; Lourenço, 2002: 102, 111, figs. 228–231; Manzanilla and Sousa, 2003: 3; Lourenço et al., 2004: 1152, 1156; Lenar- ducci et al., 2005: 1, 2, 7; Lira-da-Silva et al., 2005: 2; Teruel, 2006: 52; Lourenço, 2007: 359; 2008: 3; 2008: 3; Prendini et al., 2009: 222, 223; Outeda-Jorge et al., 2009: 44–46, 48, 49; Brazil and Porto, 2010: 50, 62; Porto et al., 2010: 293–295, table 1 View TABLE 1 ; Lourenço, 2014: 69–75, figs. 1–12; Gallão and Bichuette, 2016: 2, 3, 9–11, figs. 1, 18; Ubinski et al., 2016: 122.

DIAGNOSIS: Troglorhopalurus differs from Heteroctenus, Jaguajir , gen. nov., Physoctonus , and Rhopalurus by the proximal dentate margins of the chela fixed and movable fingers of the adult male that are linear, with no gap evident between them, when closed; from Heteroctenus, Jaguajir , and Rhopalurus by the absence of a pecten-sternite stridulatory organ; from Ischnotelson , gen. nov., and Rhopalurus by the separate (unfused) central lateral and posterior central submedian carinae of the carapace; from Heteroctenus by the presence of two lateral depressions in the male pectinal plate, and a subaculear tubercle on the telson; from Ischnotelson by the separate (unfused) lateral ocular and central lateral carinae of the carapace and the telson vesicle not being laterally compressed; from Jaguajir by the separate (unfused) lateral ocular and anterior central submedian carinae of the carapace; from Physoctonus by the larger size (35–40 mm), the more distinct carapacial carinae, the setose proximal dorsal fulcra of the pectines, the bifurcate prolateral pedal spur of leg I, and the oblique subrows of primary denticles on the pedipalp chela fingers flanked closely by pro- and retrolateral accessory (supernumerary) denticles; from Rhopalurus by the slender metasoma, not increasing in width posteriorly; and from Centruroides by the obsolete retromedian carina on the pedipalp chela manus, and the well-separated dorsointernal and proventral carinae of the pedipalp patella.

DESCRIPTION: The following general description outlines characters common to both species of Troglorhopalurus .

Total length: Medium-sized, gracile scorpions (total length, 35–40 mm) with soma slightly dorsoventrally compressed.

Color: Base color predominantly pale brown with pigmentation somewhat reduced, especially in the immature stages (fig. 1G–H). Carapace and tergites similar to or slightly darker than chelicerae, pedipalps, legs, sternites, metasoma and telson vesicle; pedipalp chela fingers darker than chela manus, patella, and femur, carinae darker than intercarinal surfaces; pectines pale yellow; metasomal segments IV and V darker than preceding segments in T. lacrau , comb. nov.; metasomal carinae darker than intercarinal surfaces; telson aculeus dark brown to black.

Chelicerae: Base, dorsal surface with medial transverse row of well-developed tubercles.

Carapace: Median ocular tubercle low (figs. 14F, 15E); two median ocelli reduced, more so in T. translucidus ; three pairs of lateral macroocelli; one pair of lateral microocelli. Anteromedian, median ocular, and posteromedian sulci well developed, forming single, almost continuous, longitudinal sulcus. Lateral ocular, central lateral, anterior central submedian and posterior central submedian carinae somewhat indistinct, finely granular and separate (unfused).

Pedipalps: Pedipalp femur retrolateral accessory carinae absent. Pedipalp chela manus of males incrassate in T. lacrau , slender in T. translucidus (fig. 61), fixed and movable fingers not curved, such that proximal dentate margin linear, no gap present between fingers proximally, when closed; manus, proventral carina present, promedian carina absent; fixed and movable fingers, median denticle rows each comprising eight ( T. lacrau ) or nine ( T. translucidus ) oblique subrows of primary denticles flanked closely by pro- and retrolateral accessory (supernumerary) denticles, smaller and more sparse in T. translucidus ; movable finger without proximal lobe ( fig. 17 View FIG. 17 F). Pedipalps orthobothriotaxic Type A, α configuration; femur with five dorsal trichobothria, trichobothrium d 2 situated on prolateral surface; patella trichobothrium d 3 situated retrolateral to dorsomedian carina; chela fixed finger trichobothrium db situated proximal to trichobothrium et.

Legs: Legs III and IV, tibial spurs absent; I–IV, basitarsi each with bifurcate prolateral pedal spur; telotarsi each with distinct pro- and retroventral rows of fine, acuminate macrosetae.

Pectines: Pectinal plate with two lateral depressions (male), anterior margin with or without sulcus (figs. 18F, 19E). Pectines not proximally expanded; proximal dorsal fulcra setose; pectinal teeth almost straight, slightly curved laterally, proximal teeth, dorsal surfaces without nodules and with irregular striations (figs. 11F, 12D), dorsobasal surfaces with or without macrosetae; pectinal sensillae elongate and acuminate.

Mesosoma: Tergites IV and VI wider than than I–III and VII; dorsosubmedian carinae vestigial or absent, dorsomedian carinae finely granular, vestigial, restricted to posterior margins of segments I–V, complete on VI (fig. 63). Tergite VII pentacarinate, dorsomedian carina restricted to anterior half of segment. Sternites III–V smooth, carinae absent or obsolete, ventromedian carina present on VI and VII; sternite III, lateral margins not forming smooth, raised carina, ventromedian carina not elevated anteriorly, ventrosubmedian surfaces not forming paired depressions, finely and irregularly granular; respiratory spiracles (stigmata) small and short, width ca. 2× length (fig. 10F).

Metasoma: Metasoma slender, not increasing in width posteriorly, I and V similar width in both sexes (fig. 62). Segments I and II each with 10 distinct, costate-granular carinae, III and IV each with eight distinct, costate-granular carinae, V with seven distinct but less pronounced, granular carinae; dorsosubmedian carinae absent or obsolete, reduced to rows of granules on dorsal surfaces of segments I–IV; dorsolateral carinae complete on segments I–IV, often terminating in prominent, spiniform granules posteriorly on III and IV, absent on V; lateral supramedian carinae complete on segments I–V; lateral inframedian carinae complete on segment I, partial on II, absent on III–V; ventrosubmedian carinae complete on segments I–IV, restricted to anterior third on V; ventromedian carina absent on segments I–IV, complete on V. Intercarinal surfaces finely granular.

Telson: Vesicle slightly elongate, not laterally compressed, width similar to metasoma V width; anterodorsal lateral lobes reduced or absent; lateral and ventral surfaces granular ( T. translucidus ) or smooth ( T. lacrau ), with distinct ventromedian carina; subaculear tubercle well developed, spinoid.

Hemispermatophore: Unknown.

Cytogenetics: The diploid chromosome number of T. lacrau is 2n = 20 and of T. translucidus , 2n = 20–22 ( Ubinski et al., 2016).

INCLUDED SPECIES: Troglorhopalurus translucidus Lourenço et al., 2004 ; Troglorhopalurus lacrau ( Lourenço and Pinto-da-Rocha, 1997), comb. nov.

DISTRIBUTION: Troglorhopalurus is endemic to northeastern Brazil, where it has been recorded in the states of Bahía and Ceará (fig. 9).

ECOLOGY: Both species of Troglorhopalurus occur under stones either inside or in close proximity to caves (fig. 2G, H).

REMARKS: Troglorhopalurus was originally monotypic, created to accommodate T. translucidus . In comparing Troglorhopalurus with Rhopalurus, Lourenço et al. (2004: 1153 , 1156) noted “all modifications presented by the new troglobitic scorpion are the result of adaptation to a cave dwelling life,” prompting Prendini et al. (2009) to suggest that Troglorhopalurus might be a junior synonym of Rhopalurus . Rhopalurus lacrau had earlier been described from caves belonging to the same subterranean formation in Brazil and, in the description of Troglorhopalurus, Lourenço et al. (2004) suggested the relationship between these taxa should be investigated using molecular data. Gallão and Bichuette (2016) subsequently identified four morphological characters shared by R. lacrau and T. translucidus , in addition to their troglomorphic habitus (metasomal carination, pectinal tooth count, pectinal peg sensillar shape, and the absence of a pecten-sternite stridulatory apparatus). A close association between the two species was independently verified in the cytogenetic study of Ubinski et al. (2016) which identified a diploid chromosome number of 2n = 20 for R. lacrau and 2n = 20–22 for T. translucidus ( table 2 View TABLE 2 ). Accordingly, the consistent placement of R. lacrau sister to T. translucidus in the analyses of Esposito et al. (in review) is rather predictable, and justifies the transfer of R. lacrau to Troglorhopalurus and the following new combination: Troglorhopalurus lacrau ( Lourenço and Pinto-da-Rocha 1997), comb. nov. (fig. 13).