Key to Australian Acerentomidae species 1. Abdominal legs II and III with 3 setae..................................................................... 2 - Abdominal legs II and III with 2 setae.................................................................... 12 2. Labial palps with apical tuft of setae, abdominal sternite VIII with 6 setae (Acerentulus)............................. 3 - Labial palps without apical tuft of setae, abdominal sternite VIII with 4 setae...................................... 4 3. Sensillum a long, extending past base of t2, a’ short and slender, not reaching base of b’ .................................................................................................... Acerentulus confinis (Berlese, 1908) 1 - Sensillum a short, not reaching base of t2, a’ long and broadened, extending past base of b’ ...................................................................... Acerentulus sexpinatus Womersley, 1936 (South and Western Australia) 4. Striate band with distinct, parallel-sided striae (Australentulus)................................................. 5 - Striate band reduced, striae invisible, hoog-shaped design presents.. Amphientulus ambiguus (Tuxen, 1967) (South Australia) 5. Abdominal tergite I with P1a setae....................................................................... 6 - Abdominal tergite I without P1a setae..................................................................... 9 6. Tergite VII with 8 A -setae (setae A1 present)................................................................ 7 - Abdominal tergite VII with 6 A -setae (setae A1 absent)............ Australentulus victoriae Tuxen, 1967 (South Australia) 7. Labrum protruded, LR = 7.0, comb with 15 long teeth...... Australentulus occidentalis (Womersley, 1932) (West Australia) - Labrum not protruded, LR more than 10, comb with less than 10 teeth........................................... 8 8. Foretarsal sensillum a long and b short, both reaching base of seta γ3, comb with 9 teeth.................................................................................... Australentulus noseki Tuxen, 1967 (West Australia, India) - Foretarsal sensillum a short, reaching base of sensillum t2, b long, extending past base of seta γ3, comb with 5 teeth................................................. Australentulus westraliensis (Womersley, 1932) (West Australia, Victoria) 9. Labrum long, LR = 5.0, abdominal tergite V with 8 A -setae (setae A4 present), tergite VII with 18 P -setae (P3a present).................................................. Australentulus reginae Tuxen, 1967 (West Australia, type area only) - Labrum short, LR more than 10.0, abdominal tergite V with 6 A -setae (setae A4 absent), abdominal tergite VII with 16 P -setae (setae P3a absent).................................................................................... 10 10. Sensillum a sword-shaped; b short, reaching base of seta γ3; sensillum a’ slender; comb with 9 long teeth...................................................................... Australentulus intermedius Tuxen, 1967 (West Australia) - Sensillum a parallel-sided; b longer, extending pass base of seta γ3; sensillum a’ broadened; comb with 5–8 short teeth... 11 11. Sensillum b short, reaching base of seta γ3, e not reaching the base of claw, comb with 8 short teeth..................................................................... Australentulus australensis (Womersley, 1932) (West Australia) 2 - Sensillum b longer, extending past base of seta γ3, e reaching the base of the claw, comb with 6 short teeth................................................................... Australentulus tillyardi (Womersley, 1932) (South Australia) 12. Abdominal legs II and III with long subapical and very short medial apical setae.................................. 13 - Abdominal legs II and III with lateral apical seta more than half as long as the subapical setae....................... 16 13. Striate band with distinct, parallel-sided striae.................................................................... Gracilentulus gracilis (Berlese, 1908) 3 (Europe, Morocco, South Africa, North America, New Zealand, South Australia) - Striate band reduced to two lines, striae invisible........................................................... 14 14. Foretarsal sensillum t1 baculiform, abdominal tergite VI with 8 A -setae, abdominal sternite I with 4 P -setae....................................................... Berberentulus capensis (Womersley, 1931) (warmer regions of the world) - Foretarsal sensillum t1 claviform, abdominal tergite VI with 6 A -setae, abdominal sternite I with 2 P -setae............. 15 15. Abdominal tergite VII with 2 A -setae (A5) and 16 P -setae (absence of P3a)..................................................................................... Baculentulus pseudonitidus Tuxen & Imadaté, 1975 (West Australia) - Abdominal tergite VII with 4 A -setae (A4, 5) and 18 P -setae (presence of P3a)..... Baculentulus breviunguis (Condé, 1961) 4 16. Striate band on VIII with easily visible striae, abdominal sternite VIII with 6 setae, accessory setae sensilliform on abdominal segments I–VI (Tasmanentulus)......................................................................... 17 - Striate band on VIII without striae, “hook-shaped” design present, abdominal sternite VIII with 4 setae, accessory setae setiform on abdominal segments I–VI (Amphientulus).............................................................. 18 17. Foretarsal sensillum b’ present, tergite VII with 8 A -setae (A1, 2, 4, 5).............................................................................. Tasmanentulus tasmanicus (Tuxen, 1967) (Western and South Australia, Tasmania) - Foretarsal sensillum b’ absent, tergite VII with 6 A -setae (A2, 4, 5)........ Tasmanentulus similis (Tuxen, 1967) (Tasmania) 18. Abdominal tergites I–VI with P1a setae.................................................................. 19 - Abdominal tergites I–VI without P1a setae................................................................ 20 19. Abdominal sternite I with 4 P -setae, tergite VII with 8 A -setae (setae A1 present), foretarsal sensillum a’ sword-shaped, b’ slender, length of foretarsus 90 μm............................. Amphientulus validus (Tuxen, 1967) (South Australia) - Abdominal sternite I with 2 P -setae, tergite VII with 6 A -setae (setae A1 absent), foretarsal sensillum a’ slender, b’ broadened, length of foretarsus 55 μm.................................. Amphientulus aestuarii (Tuxen, 1967) (South Australia) 20. Abdominal sternite I with 4 P -setae...................................................................... 21 - Abdominal sternite I with 2 P -setae...................................................................... 22 21. Abdominal tergite VII with 8 A -setae (setae A1 present); comb with 8 very short teeth; foretarsal sensillum a long, reaching base of seta γ3; length of foretarsus 50 μm....................... Amphientulus grangarae (Tuxen, 1967) (Western Australia) - Abdominal tergite VII with 6 A -setae (setae A1 absent); comb with semicircle hind margin and 5 teeth of different lengths; sensillum a short, reaching base of sensillum t2; length of foretarsus 75 μm................................................................................................ Amphientulus sinuous (Tuxen, 1967) (South Australia). 22. Abdominal tergites II–VI with P4a setae, tergite VII with 8 A -setae (seta A1 sometimes present asymmetrically); foretarsal sensilla a and g slender; length of foretarsus 80 μm..................... Amphientulus markstivensi sp. nov. (Tasmania) - Abdominal tergites II–VI without P4a setae; tergite VII with 6 A -setae (seta A1 absent); foretarsal sensilla a and g broadened; length of foretarsus 55 μm.................................... Amphientulus alienus (Tuxen, 1967) (South Australia)

Published as part of Shrubovych, Julia & D'Haese, Cyrille, 2024, Phylogeny of Australian Acerentomidae species (Protura: Acerentomidae), with a key to identification, pp. 86-104 in Zootaxa 5453 (1) on pages 101-102, DOI: 10.11646/zootaxa.5453.1.4, http://zenodo.org/record/11233458