Identification key to taxa within the Nemastoma bidentatum Roewer, 1914 complex

The identification key refers to species of the N. bidentatum complex, and subspecies of N. bidentatum s. str. including typical male hybrids. Female hybrids show intermediate traits and are not considered in the key. Figs 4–5 summarize the written information visually throughout the key, and are therefore not referred in the key. Detailed morphology is presented in Figs 6–13. Consult characters presented in Figs 6–10 and 13 (pure taxa), and Figs 11–12 (pure taxa and hybrids, males) in support.

1. ♂ ....................................................................................................................................................... 2

– ♀ ..................................................................................................................................................... 16

2. Ch and Pa slender to robust, Pa-Pt> 3.5 times as long as wide ........................................................ 3

– Ch and Pa very robust, Pa-Pt <2.8 times as long as wide (Fig. 12D) ................................................ ........................................................................................... N. pluridentatum (Hadži, 1973) stat. nov.

3. Pa-Fe unarmed or with series of small tubercles, glans isosceles triangular .................................... 4

– Pa-Fe with either spines, thorns, pointed tubercles or 4 long, rigid, subequidistant setae, glans variously shaped ............................................................................................................................................... 5

4. Ch-Apo comb-like, Pa-Fe unarmed, without terminal bonce, Pa-Pt ~ 4.0 times as long as wide (Fig. 12C) .................................................................. N. relictum Gruber & Martens, 1968 stat. nov.

– Ch-Apo rounded-trapezoidal, Pa-Fe with series of ~7 minute irregular tubercles, with terminal bonce, Pa-Pt>4.8 times as long as wide (Fig. 12I) ........................................... N. b. sneznikensis ssp. nov.

5. Ch-Apo variously shaped, Pa-Fe with spines, thorns, pointed denticles or 4 long, rigid setae on low protrusions ........................................................................................................................................ 6

– Ch-Apo low-trapezoid, Pa-Fe slightly club-shaped, with 6–11 medio-ventral pointed denticles, glans isosceles triangular (Fig. 12G) ...................................................................... N. b. martensi ssp. nov.

6. Pa-Fe robust, very club-shaped (Pa-Fe max:min width>2.5:1) and ventrally bent (e.g., Figs 10J, O, 12A, F, H) ......................................................................................................................................... 7

– Pa-Fe moderately club-shaped (Pa-Fe max:min width <2.4:1) and ventrally bent ........................ 13

7. Pa-Ti with small medio-dorsal hump, glans truncated terminally .................................................... 8

– Pa-Ti without hump, glans isosceles triangular .............................................................................. 10

8. Ch-Apo either broadly quarter moon-like or elongated oval-trapezoid ........................................... 9

– Ch-Apo narrowly quarter moon-like, ~ 2.0 times as high as wide (Fig. 9J) ....................................... ................................................................. N. b. bidentatum Roewer, 1914 × N. b. schmidti ssp. nov.

9. Ch-Apo high, broadly quarter moon-like, ~ 2.4 times as high as wide, apically sagittally shallowly bifid, Pa-Fe with evenly arched dorsal and ventral margins, Pa-Ti medio-dorsal hump conspicuous, glans terminally roundly truncated (Fig. 12A) ................................. N. b. bidentatum Roewer, 1914

– Ch-Apo elongated oval-trapezoid, with apical pinnacle posteriorly, apically sagittally shallowly bifid, Pa-Fe with knee-like bent dorsal margin and evenly arched ventral margin, with 3 stout spines in distal fourth, Pa-Ti with low medio-dorsal hump, and glans terminally evenly truncated (Fig. 12H) ........................................................................................................................ N. b. schmidti ssp. nov.

10. Pa-Fe with knee-like bent dorsal and ventral margins .....................................................................11

– Pa-Fe with evenly bent dorsal and ventral margins ........................................................................ 12

11. Ch-Apo very high, Pa-Fe with 4 stout spines in distal half (Figs 9M, 10M) ..................................... ............................................................................... N. b. gruberi ssp. nov. × N. b. schmidti ssp. nov.

– Ch-Apo high to very high, Pa-Fe with 2–3 stout spines in distal third, frontal margin bent approximately in lower quarter (Figs 9P, 10O) ........................................................................................................... .................................................... N. b. schmidti ssp. nov. × N. b. sparsum Gruber & Martens, 1968

12. Pa-Tr with high, evenly arched dorsal margin, Pa-Fe with evenly arched dorsal and ventral margins, with 4 stout, equidistant spines, Pa-Ti dorsally concave, without hump, glans isosceles triangular (Fig. 12F) ................................................................................................................ N. kozari sp. nov.

– Ch-Apo thumb-like, Pa-Fe evenly club-shaped, with 5 small denticles in distal half (Figs 9L, 10L) ............................. N. b. gruberi ssp. nov. × N. b. martensi ssp. nov. × N. b. schmidti ssp. nov.

13. Ch-Apo rhomboidal or apically extended ....................................................................................... 14

– Ch-Apo oblong with pinnacle or distinctive angle, Pa-Fe with either 2 stout spines or tubercle and pointed thorn, glans equilateral triangle (Fig. 12B) ............. N. b. sparsum Gruber & Martens, 1968

14. Ch-Apo apically extended .............................................................................................................. 15

– Ch-Apo rhomboidal, Pa-Fe with either 4 subequidistantly positioned spines or pointed tubercles or long setae on low protrusions, or their combination in the distal Pa-Fe half, or, alternatively, with 2–3 stout thorns distally, glans isosceles triangle with width 80% of length (Fig. 12E) .................... ......................................................................................................................... N. b. gruberi ssp. nov.

15. Ch-Apo apically extended in spire, Pa-Fe with 2 simple denticles (Figs 9N, 10N) ........................... ...................................................... N. b. gruberi ssp. nov. × N. b. sparsum Gruber & Martens, 1968

– Ch-Apo apically extended in narrow, finger-like protrusion, Pa-Fe with 5 equidistant denticles ...... ............................................................................... N. b. gruberi ssp. nov. × N. b. martensi ssp. nov.

16. Pa-Tr dorsal margin arched, Pa-Ti dorsal margin straight or negligibly concave .......................... 17

– Pa-Tr dorsal margin isosceles obtuse-triangular, Pa-Fe with ventral hump distally, Pa-Ti dorsal margin slightly, but conspicuously concave (Fig. 13H) ...................................... N. b. sneznikensis ssp. nov.

17. Apex of Pa-Tr dorsal margin conspicuously leaned anteriorly ....................................................... 18

– Apex of Pa-Tr dorsal margin ~in middle ....................................................................................... 19

18. Frontal margin of Ch basal article ~straight, Pa-Tr conspicuously step-wise broken anteriorly, Pa- Pt relatively robust (Pa-Pt length:width ~4.1:1) strait, Pa-Tr with conspicuous step-wise indention anteriorly, Pa-Pt relatively robust (Pa-Pt length:width ~ 4.1:1) (Fig. 13A) ........................................ ........................................................................................................... N. b. bidentatum Roewer, 1914

– Frontal margin of Ch basal article convex, Pa-Tr inconspicuously broken-bent anteriorly, Pa-Pt relatively normally proportioned (Pa-Pt length:width ~4.9:1) (Fig. 13G) ......................................... ......................................................................................................................... N. b. schmidti sp. nov.

19. Rec sem elongated saccular-like ..................................................................................................... 20

– Rec sem balloon-like ...................................................................................................................... 21

20. Ch basal article length:width ~ 2.6:1, Pa-Pt length:width ~ 4.7:1, Rec sem of 5 irregularly-saccular alveolus (Fig. 13C) ................................................... N. relictum Gruber & Martens, 1968 stat. nov.

– Ch basal article length:width ~ 2.9:1, Pa-Pt length:width ~4.7:1, Rec sem of 5 regularly-saccular alveolus originating in bladder-like structure (Fig. 13E) ........................................ N. kozari sp. nov.

21. Dorsal margin of Pa-Tr moderately high arched, Pa-Fe with conspicuous terminal widening ...... 22

– Dorsal margin of Pa-Tr highly arched, Pa-Fe in whole length equally widening (Fig. 13F) ............. ....................................................................................................................... N. b. martensi ssp. nov.

22. Dorsal margin of Pa-Tr equally arched, Pa-Fe max width behind terminal widening vs min width ~ 2.3:1 (Fig. 13B) ................................................................. N. b. sparsum Gruber & Martens, 1968

– Dorsal margin of Pa-Tr with knee-like medial flexion, Pa-Fe max width behind terminal widening vs min width ~1.9:1 (Fig. 13D) ...................................................................... N. b. gruberi ssp. nov.