Prionopetalum

Henrik Enghoff, 2016, A mountain of millipedes IV: Species of Prionopetalum Attems, 1909, from the Udzungwa Mountains, Tanzania. With notes on “ P. ” fasciatum (Attems, 1896) and a revised species key (Diplopoda, Spirostreptida, Odontopygidae), European Journal of Taxonomy 215, pp. 1-23 : 16-20

A key to the species of Prionopetalum

This key builds extensively on previous keys provided by Kraus (1960) and VandenSpiegel & Pierrard (2009).The new species described here is included, but Aquattuor fasciatus is excluded, and P. stuhlmanni is treated as a synonym of P. kraepelini (cf. above). I follow VandenSpiegel & Pierrard (2009) in not considering Spinotarsus werneri Attems, 1910 as a species of Prionopetalum , although Kraus (1960) suggested such a relationship (but still listed S. werneri under ”species incertae sedis ”).

1. Coxa with a straight, mostly long lateral spine pointing basad, laterobasad or laterad ( Fig. 9 A –L) ......................................................................................................................................................2 – Coxa different, sometimes with another type of lateral process, but not a straight basad, laterobasad or laterad spine.................................................................................................................................13

2. Lateral coxal spine directed laterad, set off by right angles from main coxal margin ( Fig. 9 A) ...... ......................................................................................................... P. megalacanthum Attems, 1912 – Lateral coxal spine different.............................................................................................................3

3. Lateral coxal spine directed basad, in part overlying main body of coxa ( Fig. 9 B) ....................... ............................................................................................................. P. frundsbergi (Attems, 1927) – Lateral coxal spine different.............................................................................................................4

4. Tip of distal telomere process (tdp) divided into two equal branches ( Fig. 10 A). Gonopod coxa profile as Fig. 9 C ............................................................ P. bifidum VandenSpiegel & Pierrard, 2009 – Tip of distal telomere process not divided into two equal branches, but one or two small subapical processes may be present..................................................................................................................5

5. Distal telomere process (tdp) ending in three dark spines ( Fig. 10 B). Gonopod coxa profile as Fig. 9 D ................................................................................................ P. tricuspis Brolemann, 1920 – Tip of distal telomere process at most with a single accessory process/spine...........................6

6. Proximal telomere process (tpp) distally expanded, asymmetrically club-shaped ( Fig. 11 A –F)......7 – Proximal telomere process not strongly expanded distally ( Fig. 11 G–K).......................................12

7. Distal telomere process (tdp) with a small accessory process ( Fig. 10 C)....................................8 – Distal telomere process without accessory process (like Fig. 10 D).............................................9

8. Lateral coxal spine relatively short, directed almost basad ( Fig. 9 E). Proximal telomere process (tpp) moderately asymmetrical ( Fig. 11 A) ............................................. P. aculeatum Attems, 1914 – Lateral coxal spine directed almost laterad ( Fig. 8 F). Proximal telomere process strongly asymmetrical ( Fig. 11 B) ............................................................. P. ndelei VandenSpiegel & Pierrard, 2009

9. Coxa mesapically rounded ( Fig. 9 G). Proximal telomere process as in Fig. 11 C ............................... ...................................................................................................................... P. serratum Attems, 1909 – Coxa mesapically with a spinous projection ( Fig. 9 H–J, arrows)................................................10

10. Distal margins of proximal telomere process (tpp) smooth ( Fig. 10 D). Gonopod coxa profile as Fig. 9 H .................................................................................................. P. dentigerum Verhoeff, 1941 – Distal margin of proximal telomere process wavy or with a denticle ( Fig. 11 E–F).........11

11. Distal margin of proximal telomere process (tpp) wavy ( Fig. 11 E). Gonopod coxa profile as Fig. 9 I ............................................................................................................. P. tanganjikum Verhoeff, 1941 – Distal margin of proximal telomere process with a single denticle ( Fig. 11 F, arrow). Gonopod coxa profile as Fig. 9 J .............................................................................. P. xerophilum (Carl, 1909) 12. Proximal telomere process (tpp) straight, apically rounded ( Fig. 11 G). Body diameter 5.5 mm. Gonopod coxa profile as Fig. 9 K ..................................................... P. clarum ( Chamberlin, 1927) – Proximal telomere process slightly curved, pointed ( Fig. 11 H). Body diameter 3 mm. Gonopod coxa profile as Fig. 9 L .............................................................................. P. pulchellum Kraus, 1960

13. Coxa with a strongly curved lateral spine ( Fig. 9 M–N)............................................................14 – Lateral coxal spine, if present, not strongly curved.....................................................................15

14. Gonopod coxa profile as Fig. 9 M. Body diameter 2.5 mm ............ P. etiennei Damange, 1982 – Gonopod coxa profile as Fig. 9 N. Body diameter 3.3–3.8 mm ........................................................ ............................................................................................ P. lindi VandenSpiegel & Pierrard, 2009

15. Lateral coxal spine sizeable, directed apicad and partly overlying main body of coxa. Coxa apically bifid ( Fig. 9 O–Q)...............................................................................................................16 – Coxa at most with a tiny lateral spine or bump ( Fig. 9 R–W).............................................18

16. Both apical branches of coxa pointed, the mesal branch hook-like ( Fig. 9 O) ................................ ................................................................................................................... P. coronatum Kraus, 1958 – Mesal-apical branch of coxa not pointed ( Fig. 9 P–Q)...............................................................17

17. Gonopod coxa profile as Fig. 9 P ........................................................ P. exaratum ( Attems, 1938) – Gonopod coxa profile as Fig. 9 Q ............................................................ P. cornutum Kraus, 1958

18. Proximal telomere process (tpp) with several lobes along one side ( Fig. 11 I). Gonopod coxa profile as Fig. 9 R ................................................................................. P. kraepelini ( Attems, 1896) – Proximal telomere process at most with a single lateral lobe ( Fig. 11 J–K)..........................19

19. Coxal apex hook-like ( Fig. 9 S). Body diameter 2.5 mm .................... P. glomeratum Attems, 1935 – Coxal apex not hook-like ( Fig. 9 T–W). Body diameter 4.4–5 mm ............................................20

20. Coxal apex with three mesad processes ( Fig. 9 T) ................................ P. urbicolum (Carl, 1909) – Coxal apex with two mesad processes ( Fig. 9 U–W)................................................................... 21 21. Both mesad processes of coxal apex pointed ( Fig. 9 U) ...................... P. suave (Gerstäcker, 1873) – Subapical mesad process of coxal apex rounded ( Fig. 9 V–W).....................................................22

22. Gonopod coxa profile as Fig. 8 V. Solenomere with a short accessory branch at c. ⅔ of its length. Proximal telomere process as Fig. 11 J. ............................................................ P. fryeri ( Turk, 1956) – Gonopod coxa profile as Fig. 8 W. Solenomere without an accessory branch. Proximal telomere process as Fig. 11 K ........................................................................................... P. asperginis sp. nov.

Figures

Fig. 8. Aquattuor fasciatus (Attems, 1896) comb. nov., syntype of Odontopyge fasciata (NHMW 2672). A. Gonopods, anterior view. B. Left gonopod, posterior view. Scale bars = 0.5 mm. Photographs: N. Akkari.

Fig. 9. Prionopetalum spp., outlines of distal part of gonopod coxa. The species appear in the sequence in which they key out in the identification key. A. P. megalacanthum (after a specimen in NHMW). B. P. frundsbergi (based on Kraus 1960). C. P. bifidum (based on VandenSpiegel & Pierrard 2009). D. P. tricuspis (based on Brolemann 1920). E. P. aculeatum (based on Kraus 1960). F. P. ndelei (based on VandenSpiegel & Pierrard 2009). G. P. serratum (based on Kraus 1960). H. P. dentigerum (based on Kraus 1960). I. P. tanganjikum (based on Kraus 1960). J. P. xerophilum (based on Kraus 1960). K. P. clarum (based on Kraus 1960). L. P. pulchellum (based on Kraus 1960). M. P. etiennei (based on Demange 1982). N. P. lindi (based on VandenSpiegel & Pierrard 2009). O. P. coronatum (based on Kraus 1958). P. P. exaratum (based on Kraus 1960). Q. P. cornutum (based on Kraus 1960). R. P. kraepelini (orig.). S. P. glomeratum (based on Attems 1935). T. P. urbicolum (based on Kraus 1960). U. P. suave (based on Kraus 1960). V. P. fryeri (based on Kraus 1960). W. P. asperginis sp. nov. (orig). Not to scale.

Fig. 10. Prionopetalum spp., outlines of distal telomere process (tdp). A. P. bifidum (based on VandenSpiegel & Pierrard 2009). B. P. tricuspis (based on VandenSpiegel & Pierrard 2009). C. P. aculeatum (based on Attems 1914). D. P. asperginis sp. nov. (orig.). Not to scale.

Fig. 11. Prionopetalum spp., outlines of proximal telomere process (tpp). A. P. aculeatum (based on Attems 1914). B. P. ndelei (based on VandenSpiegel & Pierrard 2009). C. P. serratum (based on Attems 1909). D. P. dentigerum (based on Kraus 1960). E. P. tanganjikum (based on Kraus 1960). F. P. xerophilum (based on Kraus 1960). G. P. clarum (based on Kraus 1960). H. P. pulchellum (based on Kraus 1960). I. P. kraepelini (orig.). J. P. fryeri (based on Kraus 1960). K. P. asperginis sp. nov. (orig.). Not to scale.