Stenotaenia Koch, 1847: a hitherto unrecognized lineage of western Palaearctic centipedes with unusual diversity in body size and segment number (Chilopoda : Geophilidae)

Based on morphological evidence, we newly define the genus Stenotaenia Koch, 1847 (= Scnipaeus Bergsøe & Meinert, 1866; = Simophilus Silvestri, 1896; = Onychopodogaster Verhoeff, 1902; = Insigniporus Attems, 1903; = Notadenophilus Verhoeff, 1928; = Bithyniphilus Verhoeff, 1941; = Schizopleres Folkmanova, 1956; = Euronesogeophilus Matic, 1972; all syn. nov.) as including the following 15 species: Stenotaenia linearis (Koch, 1835) (= Geophilus simplex Gervais, 1835; = Geophilus brevicornis Koch, 1837; = Scnipaeus foveolatus Bergsøe & Meinert, 1866; = Himantarium caldarium Meinert, 1886 syn. nov.; = Geophilus (Geophilus) linearis var. polyporus Verhoeff, 1896 syn. nov.; = Geophilus ormanyensis Attems, 1903 syn. nov., after lectotype designation; = Insigniporus acuneli Ca˘pus¸e, 1968 syn. nov.) from central and northern Europe; Stenotaenia frenum (Meinert, 1870) from northern Africa; Stenotaenia romana (Silvestri, 1895) (= Geophilus silvestrii Verhoeff, 1928 syn. nov.) and Stenotaenia sorrentina (Attems, 1903) (= Geophilus forficularius Fanzago, 1881 syn. nov.; = Geophilus linearis abbreviatus Verhoeff, 1925 syn. nov.) from the Italian peninsula and Sardinia; Stenotaenia antecribellata (Verhoeff, 1898) (= Simophilus albanensis Attems, 1929 syn. nov.), Stenotaenia cribelliger (Verhoeff, 1898), Stenotaenia palpiger (Attems, 1903), Stenotaenia rhodopensis (Kaczmarek, 1970), and Stenotaenia sturanyi (Attems, 1903) from the Balkan peninsula; Stenotaenia naxia (Verhoeff, 1901) (= Geophilus graecus Verhoeff, 1902) from the Aegean islands; Stenotaenia asiaeminoris (Verhoeff, 1898) and Stenotaenia bosporana (Verhoeff, 1941) from Anatolia; Stenotaenia giljarovi (Folkmanova, 1956) from western Caucasus; Stenotaenia fimbriata (Verhoeff, 1934) and Stenotaenia palaestina (Verhoeff, 1925) from Palestine; with the only exception of S. linearis, all of these binomens are comb. nov. In Stenotaenia, a strongly conserved overall morphology is matched by an unusual interspecific variation in both the body size of fully grown specimens (from 1.7 cm in S. romana to 7.7 cm in S. sturanyi) and the number of leg-bearing segments (from 43 in male S. romana to 115 in female S. sturanyi). The number of segments correlates with maximum body size.