Vaejovis mexicanus, C. L. Koch, 1836

A, Contreras-Félix Gerardo & Oscar, Francke B., 2019, Taxonomic revision of the “ mexicanus ” group of the genus Vaejovis C. L. Koch, 1836 (Scorpiones: Vaejovidae), Zootaxa 4596 (1), pp. 1-100 : 18-19

Key to identification of females of the species in the “ mexicanus ” group

1 Pedipalp patella more than three times longer than wide....................................................... 2

1’ Pedipalp patella less than three times longer than wide........................................................ 3

2(1) Large sized scorpions, over 40 mm. long; telotarsal ventral distal spinule count more than 4 on each leg; pectinal tooth counts usually 20 or more.............................................................................. V. smithi

2’ Medium to small sized scorpions, less than 40 mm. long; telotarsal ventral distal spinule count less than 4 on each leg; pectinal tooth counts less than 20......................................................................... V. darwini

3(1) Pedipalp femur more than three times longer than wide....................................................... 4

3’ Pedipalp femur less than three times longer than wide........................................................ 9

4(3) Median eyes located on a conspicuously elevated tubercle; base of the pedipalp chela fixed finger retrolateral face granular (Fig: 10-a)................................................................................... V. chiapas

4’ Median eyes located almost at level of carapace surface; base of the pedipalp chela fixed finger retrolateral face smooth (Fig: 10-b).............................................................................................. 5

5(4) Vesicle dorsally with pale area resembling a caudal gland (Fig: 10-c); pedipalp chela ventroexternal carina moderately strong, feebly granular.............................................................................. V. mexicanus

5’ Vesicle dorsally without pale area (Fig: 10-d); pedipalp chela ventroexternal carina absent, or if present smooth......... 6

6(5) Anterior margin of the carapace straight; telotarsal ventral distal spinule count 3 or more (usually 4)................... 7

6’ Anterior margin of the carapace concave; telotarsal ventral distal spinule count 3 or less (usually 2)............ V. pusillus

7(6) Pedipalp chela twice longer than wide; pectinal tooth count less than 15; metasomal segments IV-V with less than 5 setae on ventral carina........................................................................................ 8

7’ Pedipalp chela less than twice as long as wide; pectinal tooth count 15 or more (15–17); metasomal segments IV-V with more than 5 setae on ventral carinae.................................................................. V. prendinii

8(7) Pedipalp chela manus longer than the fixed finger (CM L/FF: 1.1); chela with dorsal marginal and dorsal internal carinae strong, granular................................................................................. V. dugesi

8’ Pedipalp chela manus shorter than the fixed finger (CM L/FF: 0.9); chela with dorsal marginal and dorsal internal carinae weak, feebly granular......................................................................... V. tesselatus

9(3) Vesicle ventrodistally with an aggregation of granules resembling a subaculear tubercle (Fig: 10-e).......... V. nanchititla

9’ Vesicle smooth ventrodistally, without an aggregation of granules (Fig: 10-f).................................... 10

10(9) Metasomal segment I approximately as long as wide (L/W from>0.7).......................................... 11

10’ Metasomal segment I distinctly wider than long (L/W less than <0.7)........................................... 19

11(10) Pedipalp chela with all carinae strong, densely granular (Fig: 10-g).................................. V. santibagnezi

11’ Pedipalp with all carinae smooth or only 1 or 2 feebly granular (Fig: 10-h)....................................... 12

12(11) Fixed finger longer than the chela manus.................................................................. 13

12’ Fixed finger shorter than the chela manus................................................................ 14

13(12) Anterior margin of the carapace with a weak median notch, pectinal tooth count 14 to 18.................... V sprousei

13’ Anterior margin of the carapace concave, but without a median notch, pectinal tooth counts less than 14.............. 14

14(13) Lateral carinae of sternite VII strong and granulose................................................ V. montanus

14’ Lateral carinae of sternite VII weak and slightly granular..................................................... 15

15(14) Weak basal tubercle on the prolateral face of the patella................................................ V. sierrae

15’ Strong basal tubercle on the prolateral face of the patella.............................................. V. mcwesti

16(12) Pedipalp chela manus with dorsal secondary, dorsal marginal and dorsal internal carinae moderately strong, granular.................................................................................................... V. morelia

16’ Pedipalp chela manus lacks carinae, or at most dorsal internal carina weak and feebly granular.............. V. maculosus

17(10) Anterior margin of carapace distinctly concave (Fig: 11-a).................................................... 18

17’ Anterior margin of carapace straight to slightly concave (Fig: 11-b)............................................ 20

18(17) Pedipalp chela internomedian and ventrointernal carinae weak to feebly granular, present basally only......... V. ceboruco

18’ Pedipalp chela internomedian and ventrointernal carinae strong, granular, present entire length of manus.............. 19

19(18) Intercarinal spaces on metasomal segments IV and V smooth, with few scattered granules (Fig: 11-c)........ V. coalcoman

19’ Intercarinal spaces on metasomal segments IV and V densely granulose (Fig: 11-d)....................... V. monticola

20(17) Telotarsal ventral distal spinule count of 2 on all legs........................................................ 21

20 Telotarsal ventral distal spinule count 3 or more on at least one pair of legs...................................... 24

21(20) Pedipalp chela manus thin, at least twice longer than wide................................................... 22

21’ Pedipalp chela manus slightly swollen, never twice as long as wide............................................ 23

22(21) Mesosomal sternite VII commonly with 12 setae (rarely up to 16); vesicle conspicuously rounded (L/W> 1.5).................................................................................................. V. nigrofemoratus

22’ Mesosomal sternite VII commonly with 10 setae; vesicle conspicuously thin (L/W <1.7).................... V. trespicos

23(21) Pedipalp chela external secondary carinae present; body with dark base coloration........................... V. tapalpa

23’ Pedipalp chela external secondary carina absent; body with base coloration yellowish.......................... V. talpa

24(20) Pedipalp chela manus more than twice longer than wide...................................................... 25

24’ Pedipalp chela manus twice or less longer than wide......................................................... 27

25(23) Metasomal segment V swollen (L/ W 1.4); vesicle rounded (L/ W 1.3), dorsoventrally flattened; pedipalp chela carinae well differentiated by underlying dark coloration........................................................... V. franckei

25’ Metasomal segment V thin (L/W ḵ 1.6); vesicle thin (L/W ḵ 1.5); pedipalp chela carinae not differentiated or if present, inconspicuous and without underlying dark coloration........................................................... 26

26(25) Mesosomal sternite VII with more than 12 setae (usually 16); pedipalp chela with dorsal marginal carina feebly granular; pectinal tooth counts 14–15......................................................................... V. setosus

26’ Mesosomal sternite VII with less than 12 setae (usually 10); pedipalp chela with dorsal marginal carina smooth; pectinal tooth counts 12–13................................................................................. V. rossmani

27(24) Intercarinal spaces on metasomal segments IV and V granulose; external face of pedipalp patella feebly granular.................................................................................................... V. granulatus

27’ Intercarinal spaces on metasomal segments IV and V smooth; external face of pedipalp patella smooth................ 28

28(27) Metasomal segment V with the dorsal face conspicuously wider than the ventral face, trapezoidal in cross-section (Fig: 11-e)........................................................................................... V. zapoteca

28’ Metasomal segment V with the ventral and dorsal faces almost the same width, rectangular in cross-section (Fig: 11-f)..... 7

29(28) Yellowish coloration, with the fusco-piceus pattern dispersed on all the segments; 4 ventral distal telotarsal spinules; dorsal lateral carinae on metasomal segments I-II without setae............................................... V. tenamaztlei

29’ Dark coloration, with a dense fusco-piceus pattern on all segments; 2 ventral distal telotarsal spinules; dorsal lateral carinae on segments I-II with at least 1 setae.................................................................. V. dzahui