Sahyadrimetrus, Prendini & Loria, 2020

Prendini, Lorenzo & Loria, Stephanie F., 2020, Systematic Revision Of The Asian Forest Scorpions (Heterometrinae Simon, 1879), Revised Suprageneric Classification Of Scorpionidae Latreille, 1802, And Revalidation Of Rugodentidae Bastawade Et Al., 2005, Bulletin of the American Museum of Natural History 2020 (442), pp. 1-480 : 323-332

Sahyadrimetrus , gen. nov.

Figures 4 , 8D, 9G, 10, 25C–F, 26, 39C–F, 40, 54, 55, 73–75, 198–224, tables 1, 3, 5

Type species: Pandinus scaber Thorell, 1876b: 202 [= Sahyadrimetrus scaber (Thorell, 1876) , comb. nov.], here designated.

Heterometrus (Chersonesometrus) : Couzijn, 1981: 80, 83, 131, 133, 161, 169–171, 173, 182, 184, 186–188, 192, figs. 21, 57–59, 66b, 68, 69 (part); Tikader and Bastawade, 1983: 519, 520, 573 (part).

Heterometrus (Heterometrus) : Tikader and Bastawade, 1983: 519, 520 (part); Biswas, 1984: 320; Bastawade et al., 2004: 47; Bastawade and Borkar, 2008: 212, 218; Aswathi and Sureshan, 2017: 9847 (part).

Heterometrus: Kovařík, 2004: 1 , 2, 7, 49, 51, tables 1, 2 (part); 2009: 34, 35, table 1 (part).

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1828

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FIGURE Malaysia

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.

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FIGURE Scale bar DIAGNOSIS: Species of Sahyadrimetrus may be separated from other Asian scorpionid genera as follows. The carapace is moderately to markedly dorsoventrally compressed, the lateral surfaces sloping gently (figs. 25C–F, 26A, B), in all except two species of Sahyadrimetrus , S. mathewi and S. scaber , in which the carapace is vaulted, the lateral surfaces sloping steeply (fig. 26C–F), as in Gigantometrus , Heterometrus , Javanimetrus , two species of Deccanometrus , D. latimanus and D. xanthopus , three species of Chersonesometrus , C. fulvipes , C. madraspatensis , and C. shivashankari , and all except three species of Srilankametrus , S. indus , S. pococki , and S. serratus . The carapace anterior margin is concave, with the frontal lobes uneven and sloping medially (figs. 25C–F, 26) in Sahyadrimetrus , whereas the anterior margin is straight, with the frontal lobes evenly rounded or truncate in Gigantometrus , Srilankametrus , two species of Deccanometrus , D. latimanus and D. xanthopus , and some species of Chersonesometrus . The carapace anterolateral margins converge gradually anteriorly in Sahyadrimetrus but are subparallel anteriorly in Javanimetrus and Srilankametrus . The carapace rostrolateral margin is entire in Sahyadrimetrus but distinctly incised adjacent to the posterior lateral ocelli in Heterometrus . Anterocular extensions of the superciliary carinae are present in Sahyadrimetrus but absent in Srilankametrus . The median ocelli are relatively small, the distance between them equal to or greater than the width of an ocellus in Sahyadrimetrus but relatively large, the distance between them less than the width of an ocellus in Heterometrus ; the median ocular tubercle is situated anteromedially to medially, the distance from carapace anterior margin: carapace length (CAM:CL) 0.40–0.50 in Sahyadrimetrus , but posteromedially, CAM:CL 0.51–0.62 in Chersonesometrus . The interocular suture is absent in Sahyadrimetrus but present in Chersonesometrus , Gigantometrus , and all except one species of Deccanometrus , and two species of Srilankametrus . The carapace posterior sutures are absent in Sahyadrimetrus ; present, extending to the median ocular tubercle, and connected by a short cross-suture anterior to the postocular depression in Heterometrus ; and present, extending past the median ocular tubercle, and connected anteriorly to the posterior bifurcations of the interocular suture or disconnected in Chersonesometrus , Deccanometrus , Gigantometrus , and most species of Srilankametrus . The frontal lobes and medial region of the carapace interocular surface are mostly to entirely granular in Sahyadrimetrus , whereas the interocular surface is entirely smooth in all species of Srilankametrus except S. caesar and some species of Heterometrus . The cheliceral movable finger prodistal (DI) and retrodistal (DE) teeth are unequal, with the DE tooth considerably smaller than the DI tooth, aligned longitudinally and not opposable in Sahyadrimetrus , but opposable in two species of Deccanometrus , and subequal, with the DE tooth only slightly smaller than the DI tooth, and opposable, i.e., forming a bicusp, in Heterometrus and some species of Chersonesometrus . The pedipalp patella dorsomedian carina of the female is absent or obsolete (figs. 201, 205) in all except one species of Sahyadrimetrus , S. rugosus , in which the carina is predominantly granular or costate (fig. 214), as in Chersonesometrus , Gigantometrus , and all except three species of Deccanometrus , D. latimanus , D. liurus , and D. ubicki . The prominent spiniform granule of the patella proventral carina is absent (figs. 201, 205, 210, 214, 217, 222) in Sahyadrimetrus but present in Heterometrus . The patella dorsal, retrodorsal, and retroventral intercarinal surfaces of the female are smooth or nearly so (figs. 201, 205) in all species of Sahyadrimetrus except S. rugosus , in which the surfaces are granular (fig. 214), as in all species of Chersonesometrus except C. nathanorum . The pedipalp chela of the adult male is moderately to densely setose (figs. 206, 211, 218, 223) in Sahyadrimetrus but sparsely setose in Gigantometrus , Heterometrus , Javanimetrus , most species of Srilankametrus , and some species Chersonesometrus . The distance between the chela manus dorsomedian and promedian carinae or setal rows (DMC–PMC) is slightly to markedly greater than the distance between the promedian and proventral carinae or setal rows (PMC–PVC) in Sahyadrimetrus whereas the DMC–PMC is similar to the PMC–PVC in Heterometrus . The dorsomedian carina becomes obsolete proximally in Sahyadrimetrus but is continuous to the proximal edge of the manus in Chersonesometrus , Gigantometrus , and two species of Deccanometrus , D. obscurus and D. phipsoni . The chela manus dorsal secondary, subdigital, and digital carinae (setal rows) are well separated along their entire length in Sahyadrimetrus whereas the proximal half of the dorsal secondary carina, distal half of the subdigital carina and distal third of the digital carina are closely adjacent in Chersonesometrus and Gigantomentrus. The dorsal secondary and subdigital carinae of the male are absent or obsolete in Sahyadrimetrus but present and entirely to predominantly granular or costate in Gigantometrus , all species of Chersonesometrus except C. bastawadei and C. fulvipes , and all species of Srilankametrus except S. indus and S. pococki . The chela manus digital and retromedian carinae are similarly developed (figs. 202, 206, 207, 211, 212, 215, 218, 219, 223, 224) in Sahyadrimetrus whereas the retromedian carina is more pronounced than the digital carina in Chersonesometrus . The retromedian carina of the male is absent or obsolete in Sahyadrimetrus but entirely to predominantly granular in Gigantometrus , Srilankametrus caesar , and S. serratus , and entirely to predominantly costate in Chersonesometrus , Srilankametrus couzijni , S. gravimanus , and S. yaleensis . The depression in the dorsal surface of the chela manus, proximal to the fixed finger of the adult male, is absent or obsolete (figs. 206, 211, 218, 223) in Sahyadrimetrus but present and distinct in Heterometrus . The chela manus dorsal surface is shallowly reticulate in Sahyadrimetrus but without reticulation in Gigantometrus , Srilankametrus , most species of Chersonesometrus , all except three species of Heterometrus , H. glaucus , H. laevigatus , and H. thorellii , and two species of Deccanometrus , D. obscurus and D. phipsoni ; the dorsal surface is finely to coarsely granular in all except two species of Sahyadrimetrus , S. kanarensis and S. tikaderi , in which the dorsal surface is smooth, as in Heterometrus , Javanimetrus , and one species of Dec- canometrus, D. ubicki . The chela manus ventral surface is flat, with the axes of the retroventral and ventromedian carinae in approximately the same plane in Sahyadrimetrus but angled, with the axis of the retroventral carina ventral to the axis of the ventromedian carina in Javanimetrus , four species of Chersonesometrus , C. beccaloniae , C. hendersoni , C. pelekomanus , and C. tristis , and two species of Srilankametrus , S. indus and S. pococki . The pro- and retrolateral surfaces of the tibiae of legs I and II each bear a row of two or three spiniform macrosetae in Sahyadrimetrus and scattered, setiform macrosetae, not arranged in a definite row, in Heterometrus . Macroseta st on the retroventral surface of the basitarsus of leg I is spiniform (figs. 54, 55) in Sahyadrimetrus but usually setiform in Heterometrus , and sb on the retroventral surface of the basitarsus of leg III is spiniform in Sahyadrimetrus but setiform in Deccanometrus , Gigantometrus , Srilankametrus , and most species of Chersonesometrus and Heterometrus . The pseudonychium (dactyl) of the telotarsi of legs I–IV is usually reduced and rounded in Sahyadrimetrus but prominent and acuminate in Heterometrus . The pectinal first proximal median lamella (scape) of the female is distinctly angular,> 90° but <180° (figs. 39C–F, 40) in Sahyadrimetrus but straight or shallowly curved in Srilankametrus . The mesial surfaces of mesosomal tergites I–VI of the male are smooth in all except two species of Sahyadrimetrus , S. mathewi and S. scaber , but granular in Gigantometrus , one species of Deccanometrus , D. xanthopus , and some species of Chersonesometrus . The lengths of metasomal segments I and II are approximately equal to or less than their respective widths (figs. 73, 75) in Sahyadrimetrus but markedly greater than their respective widths in Gigantometrus . The ventrosubmedian and ventrolateral carinae are granular or costate-granular on metasomal segment IV only and costate on segments I–III (figs. 74, 75) in Sahyadrimetrus but granular on segments I–IV, II–IV (costate on I), or III and IV (costate on I and II) in Gigantometrus . The ventral intercarinal surfaces of metasomal segment IV are smooth in all except one species of Sahyadrimetrus , S. tikaderi , in which the surfaces are sparsely granular, as in Javanimetrus . The dorsosubmedian carinae of metasomal segment V are vestigial (fig. 73) in Sahyadrimetrus but partial in Gigantometrus and absent in Heterometrus . The dorsal intercarinal surface of segment V is smooth in Sahyadrimetrus but granular in Gigantometrus , and some species of Chersonesometrus and Srilankametrus . The telson is paler than segment V in Sahyadrimetrus but as dark as segment V in most species of Srilankametrus , and some species of Deccanometrus and Heterometrus . The width of the telson vesicle is approximately equal to or less than the width of metasomal segment V in the female of Sahyadrimetrus but greater than the width of segment V in the female of Gigantometrus and the vesicle is elongate in Sahyadrimetrus but globose in Chersonesometrus , Deccanometrus , Gigantometrus , and three species of Srilankametrus , S. indus , S. pococki , and S. serratus .

ETYMOLOGY: The generic name refers to the Western Ghats, also known as Sahyadri, a mountain range covering an area of 140,000 km 2 in a stretch of 1600 km parallel to the western coast of the Indian peninsula, traversing the states of Gujarat, Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu. Along with many other taxa, all species in the genus are endemic to the Sahyadri.

INCLUDED SPECIES: Sahyadrimetrus , gen. nov., is hereby created to accommodate four species, formerly assigned to subgenera Chersonesometrus and the nominotypical subgenus of Heterometrus

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Camp

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1892

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Pocock.

(mm

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192

.

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by various authors ( Couzijn, 1981; Tikader and Bastawade, 1983; Fet, 2000), and two new species, recovered as a monophyletic group by phylogenetic analysis of morphological characters and DNA sequences from the nuclear and mitochondrial genomes (fig. 10): Sahyadrimetrus barberi (Pocock, 1900) , comb. nov.; Sahyadrimetrus kanarensis (Pocock, 1900) , comb. nov.; Sahyadrimetrus mathewi , gen. et sp. nov.; Sahyadrimetrus rugosus ( Couzijn, 1981) , comb. nov.; Sahyadrimetrus scaber (Thorell, 1876) , comb. nov.; Sahyadrimetrus tikaderi , gen. et sp. nov.

DISTRIBUTION: This genus is endemic to the Konkan and Malabar Coast, and the Western Ghats of southern India and recorded from the states of Goa, Karnataka, Kerala and Tamil Nadu (figs. 4, 198, 199, table 1).

ECOLOGY: Species of Sahyadrimetrus inhabit scrub forest, deciduous forest, primary and secondary lowland rainforest, swamp forest and montane forest at elevations ranging from 10−1200 m above sea level. All species of the genus are pelophilous and fossorial, constructing shallow burrows (ca. 10–40 cm deep) or scrapes in clayey, sandy-clay, or sandy-loam soils under or at the base of stones and logs, in earthen banks, among the roots of trees, or in open ground. The species of Sahyadrimetrus are allopatric with each other and with the species of other Indian scorpionid genera.

CONSERVATION STATUS: Sahyadrimetrus kanarensis and S. scaber are occasionally harvested for the commercial trade in exotic pets.

Figures

FIGURE 4. Map of South India and Sri Lanka, plotting known locality records of Sahyadrimetrus, gen. nov., and Srilankametrus Couzijn, 1981, stat. nov. et stat. rev., based on material examined, and verified records from virtual museums and the literature.