Vaejovis baggins Azzinnari, Bryson, Graham, Solís-Rojas, and Sissom, 2021

Azzinnari, Jessica S., Bryson Jr, Robert W., Graham, Matthew R., Solís-Rojas, Carlos & Sissom, W. David, 2021, A new Vaejovis C. L. Koch from the Sierra Madre Occidental of Durango, Mexico (Scorpiones: Vaejovidae), Insecta Mundi 2021 (852), pp. 1-12 : 3-10

Vaejovis baggins Azzinnari, Bryson, Graham, Solís-Rojas, and Sissom

( Fig. 2–19 , Table 1)

Type data. Holotype male (CNAN-T01428) from Rancho Santa Barbara , ca. 15 km S Hwy 40, Municipio Durango, Durango, Mexico (23°49.580′N, 104°54.896′W; 2245 m). 23 July 2013. R. W. Bryson Jr. and A. Huereca.

Paratypes. Same locality as holotype: 16 July 2010 (R. W. Bryson Jr., M. Torocco, and J. Jones), 10 adult females (CNAN-T01429) ; 23 July 2013 (R. W. Bryson Jr. and A. Huereca), five adult males, one subadult male ( CNAN- T01430), two adult males, two adult females ( UANL) ; Hwy 40 Durango – El Salto, km 91, Municipio Durango, Durango, Mexico (23°58.846′N, 105°19.155′W; 2446 m). 8 Aug 2005 (O.F. Francke, et al.), 1 adult male, 1 adult female ( AMNH) ; Hwy 40 Durango – El Salto, km 45.5, Puente Mimbres, Municipio Durango, Durango, Mexico (23°55.605′N, 104°57.118′W; 2289 m), 8 Aug 2005 (O.F. Francke, et al.), 1 adult male ( AMNH), 1 adult female (CNAN-T01431) .

Etymology. This species epithet is a noun in apposition and based on the fictional character Bilbo Baggins in J.R.R. Tolkien’s The Hobbit in reference to its small size.

Distribution. Known from three localities in the Sierra Madre Occidental southwest of Ciudad Durango in Durango, Mexico.

Diagnosis. Vaejovis baggins is most similar to V. sierrae and V.mcwesti from Durango and V. montanus from Chihuahua and Sonora. Vaejovis baggins differs from V. sierrae in the following ways: (1) V. baggins has a wider telson with the telson length to vesicle width ratio of males 2.37–2.68 and females 2.41–2.63, whereas V. sierrae has a ratio of 2.73 in the male holotype and a range of 2.71–2.83 in females; (2) V. baggins has a moderate basal tubercle on the inner face of the pedipalp patella, whereas V. sierrae has a weak basal tubercle; (3) V. baggins has a moderate dorsointernal carina of the chela with several medium-sized granules and a few large granules, but it is weak with only a few granules in V. sierrae ; (4) V. baggins has a weak dorsomarginal carina with more granules, whereas in V. sierrae it is weak and feebly granulose; (5) V. baggins most commonly has seven or more inner accessory denticles on the chela movable finger (43/44; 98%), whereas V. sierrae has six (9/14; 64%) or seven (5/14; 36%); (6) V. baggins most commonly has a setal count on the dorsolateral carinae of the metasoma of 0:0:1:1 (39/44; 89%), whereas V. sierrae most commonly has a setal count of 0:0:0:1 (12/14; 86%); and (7) V. baggins has 1–6 setae on each side when totaling all of the setae on the lateral inframedian carinae of metasoma I–IV, whereas V. sierrae is limited to one or two in total. The localities of V. baggins along Hwy 40 southwest of Ciudad Durango are also separated from the mountain range with V. sierrae by the Rio Mezquital drainage ( Fig. 1 ). This river drainage is a formidable barrier to many codistributed montane taxa ( Bryson et al. 2012).

Vaejovis baggins differs from V. mcwesti in the following ways: (1) V. baggins has more slender pedipalp chela with a length to width ratio of 3.26–3.79 in males and 3.52–3.86 in females, whereas V. mcwesti has a ratio of 3.16 in the holotype male and a range of 3.25–3.42 in females; (2) V. baggins females have a wider telson with the telson length to vesicle width ratio 2.41–2.63, whereas V. mcwesti has a ratio of 2.64–2.77; (3) V. baggins has approximately 20 granules on the internal face of the pedipalp femur, whereas V. mcwesti has approximately eight; (4) V. baggins has a granular dorsolateral carinae on metasoma V, whereas V. mcwesti is serrate anteriorly; (5) V. baggins most commonly has three setae on the ventral submedian carinae of metasoma IV (40/44; 91%), whereas V. mcwesti has four or more (11/12; 92%); (6) V. baggins has a 1+2 (29/44; 66%) or 2+2 (15/44; 34%) setal arrangement flanking the ventromedian carinae of metasoma V, whereas V.mcwesti most commonly has a 2+2 (4/12; 33%), 3+2 (3/12; 25%), or 4+2 (3/12; 25%) arrangement; and (7) V. baggins has a few granules on the ventrointernal carina on the chela, whereas it remains a smooth ridge in V.mcwesti .

Vaejovis baggins differs from V. montanus in the following ways: (1) V. baggins is a smaller species with males ranging 18.56–22.03 mm (n = 8) and females ranging 21.97–26.25 mm (n = 12) in length where V. montanus males are larger than 26.00 mm and some females (n = 4) exceed 28.00 mm in length; (2) V. baggins has pedipalp carinae that is weaker and less granulose than V. montanus ; (3) the lateral and ventral intercarinal surfaces of metasoma IV and V, as well as the underside of the telson, have only a few granules in V. baggins but are moderately to densely granular in V. montanus ; (4) V. baggins has weaker metasomal carinae; and (5) V. baggins has a 1 + 2 (29/44; 66%) or 2 + 2 (15/44; 34%) setal arrangement on the ventromedian carinae of metasoma V, whereas V. montanus most commonly has two to four anterior setae.

Description. The following description is based on the holotype male.

Coloration. Carapace and tergites dark brown, with distinct pattern of dusky markings ( Fig. 2–3 ). Metasomal segments dark brown; dorsal markings limited to posterior ends of carinae and small dark spots in dorsal intercarinal spaces; lateral fuscosity more extensive, associated with the carinae, setal pits, and intercarinal spaces; ventral fuscosity limited to carinae and setal pits; metasoma V with heavier fuscosity in posterior half. Telson orange brown with a few small dorsal and lateral dusky spots; aculeus dark reddish brown. Cheliceral manus light orange brown, dorsally with distal edge and movable finger bearing dusky markings; cheliceral teeth dark brown. Pedipalp femur and patella orange brown with small amounts of fuscosity located at or near trichobothrial setal pits. Pedipalp chela orange brown with fuscous spots surrounding trichobothria and setal pits and a band of fuscosity at distal end of manus which extends well onto fixed finger. Carinae of pedipalps and metasoma dark brown to reddish brown. Coxosternal region and sternites III–VI yellow brown, unmarked; sternite VII yellow brown with light fuscosity on posterior edge. Legs lighter yellow brown with strong fuscosity.

Prosoma. Carapace length slightly greater than posterior width; ratio of carapace L/metasomal segment V length 0.96. Median ocular prominence slightly raised above carapacial surface. Two macrosetae anterior to eyes on ocular prominence. Anterior margin obtusely emarginate; median notch rounded. Carapace densely finely granular, with scattered coarse granulation associated with fuscous areas. Posterior margin strongly fuscous. Three pairs of evenly spaced macrosetae on posterior margin.

Mesosoma. Longitudinal median carina absent on tergites I–II; on III–VI represented by faint granular ridges. Tergite VII with median carina present, weak on anterior half, granular; both pairs of lateral carinae strong, serratocrenulate. Pre-tergites densely finely granular; post-tergites densely, finely granular with scattered coarse granulation in fuscous areas. Pectinal teeth numbering 14/14. Sternite III with two anterior medial macrosetae and a transverse, row of four macrosetae near midsegment; sternites IV–VI with two macrosetae anterior to each book lung spiracle (lateral macroseta missing on left side of sternite VI) and a transverse, recurved row of four macrosetae near mid-segment; sternite VII with three pairs of lateral setae (two of these on lateral carina) and one pair of medial setae; all five sternites with regularly spaced lateral and posterior marginal macrosetae. Sternite V with an inconspicuous medial pale patch along posterior margin; anterior edge of patch evenly convex. Sternites III–VII shagreened medially, with granulation laterally (stronger and denser on posterior sternites). Sternite VII with one pair of weak, granular lateral carinae that weakens anteriorly.

Hemispermatophore ( Fig. 6–9 ). Lamelliform with strong dorsal crest on distal lamina extending approximately one-third the length of the blade; distal lamina with basal constriction, widening at middle, and distinctly tapering distally. Two dorsal “hooks” positioned just above the dorsal trough, with ectal hook distinctly larger. Ventral capsular area with a flat, rounded plate bearing a sharp prong which projects ectally.

Metasoma ( Fig. 10 ). Segment I length/width ratio 0.71, III length/width ratio 0.93, V length/width ratio 2.11. Segments I–IV: Dorsolateral carinae strong, irregularly serratocrenulate on I, crenulate on II–IV; terminal denticles distinctly enlarged, spinoid. Lateral supramedian carina on I strong, serratocrenulate, on II–IV strong, crenulate; terminal denticles enlarged, spinoid on I–III, flared on IV. Lateral inframedian carinae on I strong, complete, granulose on left, crenulate on right; on II present on posterior one-half, stronger posteriorly, crenulate; on III present on posterior one-quarter, stronger posterior, crenulate; on IV absent. Ventrolateral carinae on I moderate, serratocrenulate; on II–IV strong, serratocrenulate. Ventral submedian carinae on I weak, granular; on II moderate, crenulate; on III–IV strong, crenulate. Intercarinal spaces densely, finely granular with a few scattered coarse granules in fuscous areas. Segment V: Dorsolateral carinae stronger anteriorly, granulose. Lateromedian carinae moderate basally, weak distally; present on anterior three-fourths, granulose. Ventrolateral and ventromedian carinae strong, serrate. Intercarinal surfaces densely finely granular, with a few coarse granules ventrally in fuscous areas. Metasomal I–IV carinal setation ( Fig. 10 ): dorsolaterals, 0/0:0/0:1/1:1/1; lateral supramedians, 0/0:1/1:1/1:2/2; lateral inframedians, 1/1:0/0:0/0:0/0; ventrolaterals, 2/2:2/2:3/3:3/3; ventral submedians, 3/3:3/3:3/3:3/4; ventromedian intercarinal spaces lacking accessory setae. Setation of metasomal segment V: dorsolaterals, 3/3; lateromedians, 2/2; ventrolaterals, 4/4; ventromedians, 1/1 + 2/2.

Telson ( Fig. 10 ). Moderately slender, distinctly narrower than metasoma V and with length/depth ratio 3.11. Dorsal surface of vesicle slightly bulged. Underside of vesicle with eight pairs of macrosetae and several smaller paired setae. Ventral aspect of telson with sparse, scattered granulation.

Chelicera. Movable finger dorsally with one large distal tine, two smaller subdistal tines, one large medial tine, and one small basal tine. Ventral margin of cheliceral movable finger with well-developed serrula.

Pedipalp. Trichobothrial pattern, Type C, orthobothriotaxic ( Fig. 11–19 ). Femur ( Fig. 11 ): length/width ratio 2.99. Tetracarinate: dorsointernal carina moderate, irregularly crenulate; dorsoexternal carinae moderate, granulose; ventrointernal carina moderate, crenulate; ventroexternal carina weak, granular. All faces densely, finely granular; internal face additionally with about 20 larger, irregularly spaced, rounded granules. Internal face with one supramedial macroseta and three inframedial macrosetae; external face with two medial macrosetae. Patella ( Fig. 12–14 ): length/width ratio 2.73. Pentacarinate. Dorsointernal carina moderate, irregularly crenulate; internomedian carina oblique, moderate, irregular with several large granules and a few small granules, with pronounced basal tubercle; ventrointernal carina moderate, serrate; dorsoexternal and ventroexternal carinae moderate, granular. All faces densely, finely granular. Internal face with 2 supramedial and 2 inframedial macrosetae. Proximal slope to the basal tubercle relatively steep. Chela ( Fig. 15–19 ): dorsal marginal carina weak and granulose; dorsal secondary, digital, and external secondary carinae represented by faint, smooth, rounded ridges; dorsointernal carina moderate, with several medium-sized granules and some large granules; ventrointernal carina weak, with a few small granules; ventroexternal carinae weak, granular; ventromedian absent. Intercarinal surfaces densely, finely granular. Dentate margin of fixed finger ( Fig. 18 ) with primary denticle row

divided into six subrows by five enlarged denticles; seven inner accessory denticles. Dentate margin of movable finger ( Fig. 19 ) with primary row divided into six subrows by five enlarged denticles; apical subrow consisting of a single small denticle; seven inner accessory denticles. Dentate margins of chela fingers straight in lateral profile. Chela length/width ratio 3.56; fixed finger length/carapace length ratio 0.67.

Leg. Right telotarsus III with ventromedian spinule row terminating between a single pair of slightly offset spinules; left telotarsus III terminating between a pair of enlarged spinules; fourteen macrosetae on left and fifteen macrosetae on right (excluding superoterminal landmark macroseta) as follows (L/R): ri 1/1, rid 1/1, rit 1/1, rm 1/2, rmt 1/1, rs 1/1, rst 1/1, pi 1/1, pid 1/1, pit 1/1, pm 1/2, pmt 1/1, ps 1/1, pst 1/1 (after McWest 2009).

Measurements of male holotype (mm). Total L (additive), 20.35; carapace L, 2.73; mesosoma L, 6.17; metasoma L (additive), 8.47; telson L, 2.98. Metasomal segments: I L/W, 1.16/1.64; II L/W, 1.29/1.52; III L/W, 1.37/1.47; IV L/W, 1.82/1.42; V L/W, 2.83/1.34. Telson: vesicle L/W/D, 1.87/1.16/0.96; aculeus L, 1.11. Pedipalps: femur L/W, 2.12/0.71; patella L/W, 2.35/0.86; chela L/W/D, 3.77/1.06/1.16; fixed finger L, 1.82; movable finger L, 2.28; palm (underhand) L, 1.67.

Measurements of female paratype (mm). Total L (additive), 22.78; carapace L, 3.13; mesosoma L, 7.38; metasoma L (additive), 9.10; telson L, 3.16. Metasomal segments: I L/W, 1.21/1.79; II L/W, 1.39/1.69; III L/W, 1.47/1.62; IV L/W, 1.92/1.57; V L/W, 3.13/1.52. Telson: vesicle L/W/D, 1.92/1.26/0.94; aculeus L, 1.24. Pedipalps: femur L/W, 2.38/0.88; patella L/W, 2.65/1.01; chela L/W/D, 4.30/1.14/1.26; fixed finger L, 2.10; movable finger L, 2.58; palm (underhand) L, 1.87.

Variation. Variation in morphometric characters for both males and females is summarized in Tables 1 and 2. The 13 female specimens exhibited pectinal tooth counts as follows: there was one comb with 10 teeth, 16

combs with 12 teeth, eight combs with 13 teeth, and one comb with 14 teeth. The nine male specimens exhibited pectinal tooth counts as follows: there were 13 combs with 14 teeth, and five combs with 15 teeth.

All the specimens had six denticle subrows and inner accessory denticles on the chela fixed finger (n = 43 fingers) except for one that could not be counted. All specimens had six denticle subrows on the chela movable finger (n = 44 fingers). Nineteen of the 21 specimens had seven inner accessory denticles, one had eight with the 6 th denticle doubled, and one had five.

There was no observed variation in the numbers of macrosetae on the pedipalp femur (internal supramedials and inframedials; external medians) and patella (internal supramedians and inframedians). There was some variation in metasomal segments I–IV setal counts (n = 44 carinae), as follows: dorsolaterals, 0:0:0:1 (n = 3; 6.82%), 0:0:1:1 (n = 39; 88.64%), 0:1:1:1 (n = 2; 4.55%); lateral supramedians, 0:1:1:1 (n = 1; 2.27%), 0:1:1:2 (n = 43; 98.73%); lateral inframedians, 1:0:0:0 (n = 17; 38.64%), 1:0:0:1 (n = 4; 9.09%), 1:0:1:0 (n = 1; 2.27%), 1:1:0:0 (n = 3; 6.82%), 2:0:0:0 (n = 2; 4.55%), 2:0:0:1 (n = 1; 2.27%), 2:0:1:0 (n = 2; 4.55%), 2:1:0:1 (n = 1; 2.27%), 2:1:1:0 (n = 1; 2.27%), 2:1:1:1 (n = 7; 15.91%), 3:1:1:1 (n = 6; 6.82%); ventrolaterals, 2:2:2:3 (n = 1; 2.27%), 2:2:3:3 (n = 6; 13.64%), 2:3:2:3 (n = 2; 4.55%), 2:3:3:3 (n = 35; 79.55%); and ventral submedians I–IV, 3:2:3:3 (n = 2; 4.55%), 3:3:3:3 (n = 38; 86.36%), 3:3:3:4 (n = 4; 9.09%). All specimens had no accessory setae except for one on metasoma IV. For segment V: dorsolaterals, 3 (n = 41; 93.18%), 4 (n = 3; 6.82%); lateromedians, 2 (n = 24; 54.55%), 3 (n = 20; 45.45%); ventrolaterals, 3 (n = 1; 2.27%), 4 (n = 38; 86.36%), 5 (n = 4’ 9.09%), 6 (n = 1; 2.27%); the ventromedian carinae bore 2+2 (n = 15; 34.09%) or 1+2 macrosetae (n = 29; 65.91%).

Two more hemispermatophores were dissected, and one lacked the dorsal crest on the blade whereas the other matched the morphology of the first.

Genetic comparisons. The uncorrected pairwise sequence divergence between V. baggins and other Vaejovis in the Sierra Madre Occidental ranged from 8.10% ( V. baggins vs V. sierrae ) to 6.73% ( V. baggins vs V.mcwesti ). Phylogenetic analyses of mitochondrial DNA ( Fig. 20 ) placed V. baggins and V.mcwesti together in a clade that was divergent from the southern species V. sierrae , consistent with the expectation that the low-elevation Mezquital River drainage may be acting as a filter barrier to highland taxa ( Bryson et al. 2011, 2012). Vaejovis baggins and V. mcwesti were estimated to have shared a common ancestor during the late Miocene or Pliocene (3–8 Mya; Fig. 20 ). Based on mean estimated divergence dates, the montane species of Vaejovis in the Sierra Madre Occidental likely diverged around 5–13 Mya ( Fig. 20 ).

Figures

Figure 1. Type localities of species of the mexicanus group of Vaejovis C. L. Koch 1836 from the main massif of the Sierra Madre Occidental: V. montanus Graham and Bryson 2010, V. sierrae Sissom, Graham, Donaldson, and Bryson 2016, V. mcwesti Sissom, Graham, Donaldson, and Bryson 2016, and V. baggins new species. (white dot represents type locality; two black dots represent paratype localities).

Figure 20. Time-calibrated mitochondrial phylogeny showing the relationship of Vaejovis baggins new species to other species of montane Vaejovis from the Sierra Madre Occidental. Posterior probabilities indicated at nodes. Bars represent highest posterior densities (95%) around mean date estimates. GenBank accession numbers are provided in parentheses.

Figures 2–5. Vaejovis baggins new species, from Rancho Santa Barbara, Durango, Mexico. 2) Ventral aspect, male holotype. 3) Dorsal aspect, male holotype (CNAN-T01428). 4) Ventral aspect, female paratype. 5) Dorsal aspect, female paratype (CNAN-T01429). Scale line = 5 mm.

Figures 6–9. Right hemispermatophore of Vaejovis baggins new species. 6) Dorsal surface of hemispermatophore. 7) Ventral surface of hemispermatophore. 8) Ectal view of midsection. 9) Ectoventral aspect of capsular disk.

Figures 10–19. Morphology of Vaejovis baggins new species, based on male holotype. 10) Lateral view of metasoma and telson. 11) Right pedipalp femur, dorsal. 12) Right pedipalp patella, dorsal. 13) Right pedipalp patella, external. 14) Right pedipalp patella, ventral. 15) Right pedipalp chela, dorsal. 16) Right pedipalp chela, external. 17) Right pedipalp chela, ventral. 18) Apposable dentate margin of chela fixed finger. 19) Apposable dentate margin of chela movable finger.