Key to the known Iranian species of Tullbergiidae (adapted from Fjellberg, 1998; Castaño-Meneses et al., 2000)

1 Sense organ of antennal segment III in adults with one greatly thickened dorsal sensory club. ............... ......................................................................................................................... Doutnacia xerophila Rusek, 1974

— Sense organ of antennal segment III in adults with 2–3 greatly thickened dorsal sensory clubs. ............ 2 2 Abdominal segment VI without midventral projection. ................................................................................ 3

— Abdominal segment VI with midventral projection-best seen in ventral view. [Genus Metaphorura Stach, 1954] ............................................................................................................................................................ 7

3 Sense organ of Antennal segment III with 2 sense clubs. ............................................................................. 4

— Sense organ of Antennal segment III with 3 sense clubs. .............................................................................. 6

4 Post antennal organ with six v-shaped vesicles. ......... Wankeliella bescidica Smolis & Skarzynski, 2004

— Post antennal organ with simple vesicles in two rows. ................................................................................ 5

5 Abdominal segment VI with additional dorsal or lateral tubercles bearing strong bristles. ...................... ............................................................................................................. Paratullbergia callipygos (Börner, 1902)

— Abdominal segment VI dorsally smooth except for crescentic ridges. [Genus Mesaphorura Börner, 1901] ...................................................................................................................................................................... 9

6 Sixth abdominal segment with 1+1 dorsolateral spines in front of posterior anal spines. .......................... ............................................................................................. Fissuraphorura duplex (Lucianez & Simon, 1992)

— Sixth abdominal segment without dorsolateral spines in front of posterior anal spines. ........................... .............................................................................................................................. Tullbergia simplex Gisin, 1958

7 Median process spiniform or stout; Post antennal organ with 18–25 bilobated or trilobated vesicles. ..... ........................................................ Metaphorura riozoi Castaño-Meneses, Palacios-Vargas & Traser, 2000

— Median process spiniform; Post antennal organ with 20–25 simple vesicles. ............................................. 8

8 Pseudocellar formula 11/111/11111. ....................................................... Metaphorura affinis Börner, 1902

— Pseudocellar formula 11/122/22221. ......................................................... Metaphorura denisi Simon, 1985

9 Abdominal segment with 3+3 short a-setae between long a 4 setae. .......................................................... 10

— Abdominal segment with 2+2 short a-setae between long a 4 setae. ........................................................... 1 3

10 Abdominal segment with p 1 –p 1 distance shorter than p 2 –p 2. ..................................................................... 11

— Abdominal segment with p 1 –p 1 distance longer than p 2 –p 2 ......................................................................... 1 2

11 Anal lobe with l 2ʹ present. ............................................................. Mesaphorura macrochaeta (Rusek, 1976)

— Anal lobe with l 2ʹ absent. ............................................................... Mesaphorura krausbaueri (Börner, 1901)

12 Thoracic segments II–III with pseudocelli in median position, between p 3 –p 4; Abdominal segment IV without m 5. ................................................................................................... Mesaphorura yosii (Rusek, 1867)

— Thoracic segments II–III with pseudocelli in lateral position, between p 5 –p 5; Abdominal segment IV without m 5 present. ............................................................................... Mesaphorura italica (Thibaud, 1996)

13 Thoracic segments III with a 2 present. ......................................................... Mesaphorura critica Ellis, 1976

— Thoaxic segments III with a 2 absent. .............................................................. Mesaphorura jirii Rusek, 1982