Palamnaeus tristis Henderson, 1919: 380–381

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 : 119-125

Palamnaeus tristis Henderson, 1919: 380–381 ,

pl. XXI, figs. 3, 4.

Heterometrus tristis: Takashima, 1945: 94 ; Kovařík, 2004: 1 , 44, 49, 51, 52, tables 2, 3; 2009: 35, 36, 45, tables 1, 2; Javed et al., 2010b: 785, table 1.

Heterometrus (Chersonesometrus) pelekomanus: Couzijn, 1981: 137 , 139, 169, 170, fig. 58 (misidentification, part); Tikader and Bastawade, 1983: 577, 641, 642, 644, 646 (part); Fet, 2000: 440 (part).

Heterometrus (Chersonesometrus) tristis: Couzijn, 1981: 42 , 87, 156–158, 169, 171, 192, table 7, figs. 51, 59; Tikader and Bastawade, 1983: 574, 582–587, figs. 1539– 1552; Kovařík, 1998: 137; Fet, 2000: 442; Indra, 2009: 141.

Heterometrus (Chersonesometrus) palekomanus: Indra, 2001: 56 , 58 (misidentification, part).

Heterometrus mysorensis Kovařík, 2004: 1 , 7, 29, 30, 51, 52, tables 1–3, fig. 21; 2009: 35, 36, 42, 46, 48, 49, 86, 101, 109, tables 1, 2, figs. 89–94, 215, 216, 259–262; syn. nov.

Heterometrus wroughtoni: Kovařík, 2004: 1 , 7, 46, 49, 51, 52, tables 2, 3 (misidentification, part); 2009: 35, 36, tables 1, 2 (misidentification, part).

Heterometrus (Chersonesometrus) pelekomanus: Indra, 2009: 141 (misidentification, part).

Heterometrus (Chersonesometrus) tristis: Indra, 2009: 141 .

TYPE MATERIAL: INDIA: Karnataka: Mandya Distr.: Heterometrus mysorensis : Holotype ♂ (FKPC), Mysore, Maddur env. [Madduru, 12°35′N 77°03′E], ca. 900 m, 1983. Andrha Pradesh: Arcot Distr.: Palamnaeus tristis : Holotype ♂ (ZSI 2422/17), Tirupati Hills [13°39′N 79°25′E], North Arcot District, S.K. Sundaracharlu.

Although Henderson (1919: 380) listed two males from the Tirupati Hills, North Arcot District, and two females and one immature male from the Venkatagiri Hills, Nellore District, the description was based on an adult male, and the “type-specimen” explicitly identified as ZSI 2422/17. Therefore, one of the two males from the Tirupati Hills is the holotype and no other specimens are types. Couzijn (1981: 157) mistakenly listed an adult male holotype and adult male paratype from the Tirupati Hills, and an allotype female from the Venkatagiri Hills, all with the number ZSI 2160/18. Tikader and Bastawade (1983: 587), mistakenly listed a male and a female “type specimens” (ZSI 2160/18), and Fet (2000: 442) followed Couzijn (1981).

DIAGNOSIS: Chersonesometrus tristis may be separated from other species of Chersonesometrus as follows. The carapace is markedly dorsoventrally compressed, the lateral surfaces sloping gently (fig. 15E, F) in C. tristis , but vaulted, the lateral surfaces sloping steeply, in C. fulvipes , C. madraspatensis , and C. shivashankari . The carapace interocular surface is granular along the median longitudinal and anterior bifurcated sulci only in the female (fig. 15F) of C. tristis , whereas the frontal lobes and medial region of the interocular surface are granular with smooth areas in the female of C. bastawadei , C. madraspatensis , C. pelekomanus , and C. shivashankari . The carapace posterolateral surfaces of the female are smooth in C. tristis but granular in C. bastawadei , C. fulvipes , and C. madraspatensis . The cheliceral movable finger prodistal (DI) and retrodistal (DE) teeth are subequal, with the DE tooth only slightly smaller than the DI tooth, and opposable, i.e., forming a bicusp, in C. tristis but unequal, with the DE tooth considerably smaller than the DI tooth, aligned longitudinally and not opposable in C. bastawadei , C. fulvipes , C. madraspatensis , C. shivashankari , and C. wroughtoni . The pedipalps of the adult male are long, with femur length: posterior carapace width ratio (FL:PCW) ≥ 0.80 and femur length: carapace length ratio (FL:CL) ≥ 0.76 (fig. 110) in C. tristis but short, with FL:PCW <0.77, FL:CL <0.74 in all other species except C. beccaloniae and C. madraspatensis . The pedipalp patella dorsal surface is flat or nearly so, with the axes of the dorsomedian and retrodorsal carinae in the same plane (fig. 112), in C. tristis but convex, with the axis of the dorsomedian carina dorsal to the axis of the retrodorsal carina in all other species except C. beccaloniae , C. hendersoni , and C. pelekomanus . The patella retrodorsal carina of the female is as strongly developed as or more strongly developed than the retromedian carinae in C. tristis but absent or obsolete in C. nathanorum . The retromedian carinae are granular in C. tristis but costate in C. nathanorum . The patella dorsal, retrodorsal, and retroventral intercarinal surfaces of the female (fig. 112) are granular in C. tristis but smooth or nearly so in C. nathanorum . The pedipalp chela is infuscate and similar in color to the femur and patella in C. tristis but immaculate and paler than the femur and patella in C. shivashankari . The chela of the adult male is moderately to densely setose in C. tristis but sparsely setose in C. fulvipes , C. madraspatensis , and C. shivashankari . The chela manus dorsal surface (between the dorsomedian and digital carinae) is flat in the male and female of C. tristis , flat in the male and curved, i.e., slightly to markedly convex, in the female of C. bastawadei , C. beccaloniae , C. fulvipes , C. nathanorum , and C. wroughtoni , and curved in the male and female of C. madraspatensis and C. shivashankari . The proximal margin (lobe) of the chela manus dorsal surface is moderately curved and proximal to the proximal margin of the retrolateral surface in the male (fig. 113A), or aligned with the proximal margin of the condyle (articulation with patella) in the female (fig. 113B) of C. tristis ; moderately curved and aligned with the proximal margin of the retrolateral surface in the male, or aligned with or proximal to the proximal margin of the retrolateral surface in the female of C. beccaloniae and C. nathanorum ; and markedly curved and proximal to the proximal margin of the condyle in the male and female of C. hendersoni and C. pelekomanus . The maximum distance between the dorsomedian and dorsal secondary carinae (DMC–DSC) of the chela manus is similar to the maximum distance between the dorsal secondary and digital carinae (DSC–DC) in the male of C. tristis , but greater than the DSC–DC in the male of all other species except C. beccaloniae , C. madraspatensis , C. nathanorum . The dorsal secondary and subdigital carinae of the male are entirely to predominantly granular (fig. 113A) in C. tristis , entirely to predominantly costate in C. nathanorum , and absent or obsolete in C. bastawadei and C. fulvipes . The digital carina is entirely to predominantly granular in C. tristis , entirely to predominantly costate in C. nathanorum , and absent or obsolete in C. bastawadei , C. fulvipes , C. madraspatensis , and C. shivashankari . The manus dorsal intercarinal surface is without reticulation in C. tristis but shallowly reticulate in C. nathanorum . The manus ventral surface is angled, with the axis of the retroventral carina ventral to the axis of the ventromedian carina in C. tristis but flat, with the axes of the retroventral and ventromedian carinae in approximately the same plane in all other species except C. beccaloniae , C. hendersoni , and C. pelekomanus . The legs are very dark or heavily infuscate (figs. 9B, 110, 111) in C. tristis but pale or very lightly infuscate in C. bastawadei , C. fulvipes , C. hendersoni , C. madraspatensis , and C. shivashankari . Macroseta st on the retroventral surfaces of the basitarsi of legs I and II is spiniform (fig. 43I–L) in C. tristis but setiform in C. nathanorum and C. shivashankari . The mesial surfaces of mesosomal tergites I–VI are smooth in the male and the lateral surfaces smooth in the female of C. tristis , whereas the mesial surfaces are granular in the male of C. nathanorum , the lateral surfaces granular in the female of C. beccaloniae , C. hendersoni , C. pelekomanus , and C. wroughtoni , and the mesial surfaces granular in the male and the lateral surfaces granular in the female of C. bastawadei , C. fulvipes , C. madraspatensis , and C. shivashankari . The ventral surface of mesosomal sternite VII bears a pair of weakly developed ventrolateral carinae in C. tristis and two pairs of moderately to strongly developed ventrosubmedian and ventrolateral carinae in C. beccaloniae , C. hendersoni , and C. pelekomanus . The dorsosubmedian carinae are costate on metasomal segments I and II or I–III and granular or costate-granular on III and IV or IV (fig. 58E) in C. tristis but granular or costate-granular on segments I–IV in all other species, except the female of C. beccaloniae . The ventral intercarinal surfaces of segment IV are granular in the male and female (fig. 60E) of C. tristis but smooth in the male and female of C. wroughtoni , the male of C. bastawadei , C. fulvipes , and C. shivashankari , and the female of C. beccaloniae and C. nathanorum . The dorsolateral carinae of metasomal segment V are strong and continuous in C. tristis but weak and discontinuous to absent in C. nathanorum . The dorsal intercarinal surface of segment V is smooth in the male and female of C. tristis , granular in the male and female of C. bastawadei , C. hendersoni , and C. pelekomanus , and granular in the male of C. wroughtoni .

DISTRIBUTION: This species is endemic to India and has been recorded in the states of Andhra Pradesh, Karnataka, and Tamil Nadu (fig. 80, table 1). Records of H. pelekomanus from Mysore, environs of Bangalore (MNHN RS 7804) in Karnataka, and the Tirumalai Hills, Tirupati (MNHN RS 4499) in Andhra Pradesh, cited by Couzijn (1981), are referable to C. tristis .

ECOLOGY: Chersonesometrus tristis inhabits the rocky granite or quartzite/sandstone slopes and ravines of several small mountain ranges, e.g., the Tirumalai Hills and the Venkatagiri Hills, at elevations of 150−915 m on the Deccan Plateau (fig. 7B). The known locality records occur in arid to semiarid areas of deciduous broadleaf woodland on clayey to sandy-loam soils. As noted by Henderson (1919: 380), this species inhabits “short burrows,” or scrapes, under large stones, as well as the cracks and crevices of rock and earthen walls, usually in humid, shaded locations. Specimens observed with UV light detection were abundant in suitable habitat at night and under stones during daytime (P. Jain, personal commun.). The habitat and habitus, especially the dorsoventrally compressed carapace and pedipalp chelae, are consistent with the pelophilous, fossorial and semilithophilous ecomorphotypes ( Prendini, 2001b). This species is sympatric with the buthids Charmus indicus , Hottentotta rugiscutis , and Lychas tricarinatus and several species of Reddyanus across its distribution.

CONSERVATION STATUS: Chersonesometrus tristis is occasionally offered in the exotic pet trade, under the name H. mysorensis .

REMARKS: This species was previously accommodated in subgenus Chersonesometrus of Heterometrus by various authors (e.g., Couzijn, 1981; Tikader and Bastawade, 1983; Fet, 2000).

Kovařík (2004: 29) described H. mysorensis , collected in Mysore and Chittoor, and compared it with H. phipsoni , noting that H. mysorensis “is close to H. phipsoni , but has conspicuous rows of granules (carinae) on the chela and only slightly tuberculate patella of pedipalp, whereas in H. phipsoni the chela is strongly granulose.”

Kovařík (2004: 29) did not examine the holotype of Palamnaeus tristis but suggested based on Henderson’s (1919: 380) figure 3 that it could be a junior synonym of H. gravimanus “with which it shares the shape of pedipalps and the presence of carinae on the chela.” However, Couzijn (1981) and Tikader and Bastawade (1983) each presented detailed redescriptions of H. tristis , based on the holotype, accompanied by illustrations in the case of Tikader and Bastawade (1983), from which it is clear that H. mysorensis is conspecific with C. tristis , based on the similar carapace shape and granulation, chela shape, granulation, and carination, as well as metric and meristic data. For example, the total length of the male of H. mysorensis is 118 mm, the total length of the male of C. tristis is 116 mm, according to Henderson (1919), or 120 mm according to Couzijn (1981), and the total length of the female is 110 mm ( Couzijn, 1981). The pectinal tooth count is 16/ 17 in the male of H. myso- rensis, compared with 17/ 17 in the male and 14/ 15 in the female of C. tristis . The counts of pro- and retroventral spiniform macrosetae on the leg telotarsi are 5−6/6−7 on legs III and IV in H. mysorensis , 4/6, 4−5/6−7, 5/6−7, 5/7 on legs I−IV in the male and 4/5−6, 4/6, 5/6−7, 5/7 on legs I−IV in the female of C. tristis . Kovařík (2004) distinguished H. mysorensis from H. wroughtoni and H. pelekomanus , which was regarded as a junior synonym of the latter, by the sexual dimorphism in the pedipalp shape: the pedipalps of the male are longer and narrower than those of the female in H. mysorensis unlike H. pelekomanus , in which they are similar (this character cannot be evaluated for H. wroughtoni , as the adult male of that species is unknown). However, adult male specimens from the vicinity of the type locality of P. tristis , in the Chittoor area, examined during the present investigation (fig. 80), which appear to be conspecific with adult female specimens from Chittoor identified as H. mysorensis by Kovařík (2009: 42, 86, figs. 92–94) display sexually dimorphic pedipalps, proving that the character cited as diagnostic for H. mysorensis by Kovařík (2004, 2009) occurs in C. tristis . DNA sequence data obtained from samples originating from the vicinities of the type localities of H. mysorensis and C. tristis also failed to differentiate among the two species. The combination of evidence leads to the inescapable conclusion that H. mysorensis and C. tristis are conspecific and the following new synonym is therefore presented: Heterometrus mysorensis Kovařík, 2004 = Chersonesometrus tristis ( Henderson, 1919) , syn. nov.

MATERIAL EXAMINED: INDIA: viii.1973, Chowdaiah, 1 subad. ♀, 2 juv. ♂ (MNHN RS 6558). Andhra Pradesh: Chittoor Distr.: Ithepalli / Agarala, NW of, 13°35′N 79°15′E, 340 m, 1.xii.2004, S. Basi, rocky granite hillslopes and ravine, broadleaf savanna with moderate grass layer on sandy loam, many large and small granite boulders, in crevices or cracks in earthen and rock walls in ravine, 2 ♂ [1 ♂ remains], 1 subad. ♂, 1 juv. ♂ (AMNH), 1 juv. ♂ (AMCC [LP 13135]) ; Palmaner [13°12′N 78°45′E], 6 mi. W, 725 m, 26.ii.1962, E.S. Ross and D.Q. Cavagnaro, 1 juv. ♀ (CAS 9070407) ; Tirumalai Hills [Tirumala, 13°41′N 79°21′E], Tirupati, R.P. Sreenivasa-Reddy, 1 subad. ♀, 2 juv. ♂, 2 juv. ♀, 1 subad. (MNHN RS 4499). Kadapa Distr.: Highway 58, between Rajukunta and Rapur, 14°11′N 79°25′E, 289 m, 12.ii.2004, S. Basi, steep mountain slope, semideciduous broadleaf forest with shale outcrops and loose stones on clayey-loam, in scrape under stone, 1 juv. ♂ (AMCC [LP 13136]), 14°12′N 79°28′E, 148 m, 12.ii.2004, S. Basi, slopes of small rocky hill, semideciduous broadleaf woodland on clayey loam, many quartzite/sandstone outcrops and loose stones, in shallow scrape under stone, 1 juv. ♀ (AMNH). Karnataka: Bengaluru Distr. : Mysore state, env. Bangalore [Bengaluru, 12°59′N 77°35′E], 8.v.1974, Geethamali, 1 juv. ♀ (MNHN RS 7804). Cuddapah Distr. : Mysore, Kamalapuram [14°37′N 78°40′E], 6.ix.1912, Y.R. C.M., 1 juv. ♀ (BMNH). Mandya Distr. : Maddur [Madduru, 12°35′N 77°03′E], iii.2003 [juv. born in captivity on 26.ix.2001], 1 ♀ (AMNH), 1 juv. ♂ (AMCC [LP 2275]), 1 juv. ♀ (AMCC [LP 2276]). Mysore Distr: Mysore [Mysuru, 12°18′N 76°38′E], M. Seiter, 1 ♂, 1 ♀, 1 juv. (NHMW 28529) .