Stenotaenia, KOCH, 1847

Bonato, Lucio & Minelli, Alessandro, 2008, Stenotaenia Koch, 1847: a hitherto unrecognized lineage of western Palaearctic centipedes with unusual diversity in body size and segment number (Chilopoda: Geophilidae), Zoological Journal of the Linnean Society 153 (2), pp. 253-286 : 255-259

GENUS STENOTAENIA KOCH, 1847

Stenotaenia Koch, 1847: 85 , 187. Bergsøe & Meinert, 1866: 99. Pocock, 1890: 66. Attems, 1929a: 330.

Scnipaeus Bergsøe & Meinert, 1866: 95 . Cook, 1896: 75. Pocock, 1901: 330. Syn. nov.

Simophilus Silvestri, 1896: 154 . Attems, 1903: 170, 272; 1926: 362; 1929a: 195; 1929b: 334; 1947: 109. Brölemann, 1909a: 332. Geophilus (Simophilus) : Verhoeff, 1941a: 89. Syn. nov.

Onychopodogaster Verhoeff, 1902: 560 ; 1925: 73. Attems, 1926: 362. Geophilus (Onychopodogaster) : Brölemann, 1909b: 211. Verhoeff, 1924a: 413; 1928: 267; 1934a: 9; 1934b: 114; 1937a: 97; 1938: 346; 1941a: 89; 1943b: 79; 1945: 311. Syn. nov.

Insigniporus Attems, 1903: 269 ; 1909: 36; 1926: 362; 1929a: 208; 1947: 108. Brölemann, 1909a: 332. Folkmanova, 1928: 124; 1929: 36; 1956: 1641 (misspelled as Insignoporus). Căpuşe, 1968: 699. Matic, 1972: 121. Syn. nov.

Notadenophilus (subgenus of Geophilus ) Verhoeff, 1928: 268. Syn. nov.

Bithyniphilus Verhoeff, 1941b: 40 ; 1945: 4, 6. Chamberlin, 1952: 198. Syn. nov.

Schizopleres Folkmanova, 1956: 1640 . Syn. nov.

Euronesogeophilus (subgenus of Nesogeophilus ) Matic, 1972: 99. Syn. nov.

Type species: Geophilus linearis Koch, 1835 ; by subsequent designation ( Pocock, 1890: 66).

Brief description (based on an adult): Head capsule: cephalic plate only slightly longer than wide; frontal line not evident. Antennae: about two or three times as long as the head; apical sensilla spear-like, only slightly swollen at mid-length, c. 10–12-Mm long; clublike sensilla, c. 10–12-Mm long, on both sides of antennal article XIV. Clypeus: uniformly areolate, without ‘clypeal areas’, i.e. distinct areas with finer areolation; setae arranged approximately in two or three transverse rows, on the anterior part of the clypeus; a pair of distinct, not areolate, transversally elongated areas along the posterior margin. Labrum: margin slightly projecting backwards into a medial, obtuse angle with concave sides; a row of slender, pointed, finely ciliated filaments along the margin, projecting backwards; a few stout tubercles sometimes present at the midpoint of the margin. Mandible: ventral side swollen, covered with dense, hair-like projections. First maxillae: one or two pairs of lappets covered with scales. Second maxillae: telopodite bearing a slender, pointed claw. Forcipular segment: tergum c. 2.0–2.5 times as wide as long; exposed part of coxosternum wider than long, anterior margin without evident teeth, pleurocoxal margins completely ventral, evidently convergent backwards; chitin lines evident, either reaching the condyles of the coxosternum or not; forcipules shorter than the maximum width of the coxosternum, basal article wider than long, evidently narrowing distad; intermediate articles extremely short to apparently coalescent; tarsungulum gradually narrowing, its internal margin entire; mesal sides of forcipules without any evidence of tubercles; calyx of poison gland elongated, reaching the basal article. Leg-bearing segments: sternal pores arranged into a single, rounded to oval, medio-posterior area on each of the anteriormost and posteriormost segments, but arranged into two distinct, transversally paired areas on each of the intermediate segments; anterior margin of sterna without evident ‘carpophagus’ sockets. Last leg-bearing segment: tergum subtrapezoid, wider than long; sternum subrectangular to trapezoid, wider than long, either not evidently or only slightly narrowing backwards; channels of coxal glands mostly converging into two pouches on the internal margin of each coxopleuron, which open on the anterior end and on the ventral median point, respectively; telopodite only slightly longer than the telopodite of the penultimate leg-bearing segment; relatively dense, short setae on the ventral side of the telopodite; claw well developed. Terminal segments: female gonopods in the shape of an entire, short, slightly bilobate lamina.

Differential diagnosis (differences from most similar and possibly most closely related genera; see also Table 1 and Fig. 1 ): Stenotaenia Koch, 1847 differs from Geophilus Leach, 1814 mainly in having a relatively shorter basal article of the forcipule, forcipular tarsungulum without basal tubercle, trunk sterna without ‘carpophagus’ sockets, sternal pores in the anterior part of the trunk arranged in a longitudinally elongate oval area, instead of a transversally elongate band, and coxal glands opening in common pouches, instead of through independent pores. Stenotaenia Koch, 1847 differs from Clinopodes Koch, 1847 mainly in having sternal pores in the anterior part of the trunk arranged in a longitudinally elongate oval area, instead of a transversally elongate band, and legs of the last pair bearing well-developed claws. Stenotaenia Koch, 1847 differs from Tuoba Chamberlin, 1920 mainly in having a relatively shorter basal article of the forcipule, forcipular tarsungulum without basal tubercle, trunk sterna without ‘carpophagus’ sockets, sternal pores in the anterior part of the trunk arranged in a longitudinally elongate oval area, instead of a transversally elongate band, and coxal glands opening in two pouches, instead of a single pouch.

Taxonomic history: Stenotaenia Koch, 1847 is the oldest among all of the available genus-group names of which the type species are included here in this genus. Koch (1847) introduced Stenotaenia to include the two species Geophilus linearis Koch, 1835 and Geophilus acuminatus Leach, 1815 , but failed to select a type species. Most subsequent authors recognized that these two species are so different as to deserve being assigned to different genera, as G. linearis and Scolioplanes acuminata , respectively ( Latzel, 1880, 1885; Haase, 1881; Sselivanov, 1884; Daday, 1889a; Attems, 1895, 1903; Verhoeff, 1902– 25). Therefore, Stenotaenia was most often considered as an invalid taxon, and was usually listed as a synonym of both Geophilus Leach, 1814 and Scolioplanes Bergsøe & Meinert, 1866 , mostly ignoring that G. linearis had been validly designated as the type species of Stenotaenia by Pocock (1890), and even irrespective of the principle of priority ( Latzel, 1880; Haase, 1881; Sselivanov, 1884; Daday, 1889a; Verhoeff, 1902–25; Attems, 1903; Berlese, 1903; Brade-Birks, 1934; Matic, 1972). In his fundamental monograph on world geophilomorphs, Attems (1929a)

Characters are based on type species only. Differences in respect to Stenotaenia are in italics.

registered Stenotaenia as a taxon of uncertain status. Indeed, the name Stenotaenia was not used as valid after Fanzago (1881a).

Remarks on synonyms

Scnipaeus Bergsøe & Meinert, 1866 . The genus Scnipaeus was introduced by Bergsøe & Meinert (1866) to include the two new species Scnipaeus sodalis Bergsøe & Meinert, 1866 and Scnipaeus foveolatus Bergsøe & Meinert, 1866 , but no type species was fixed at that time. Scnipaeus foveolatus was subsequently designated as the type species by Cook (1896). For a long time these two nominal species were recognized as junior synonyms of Geophilus carpophagus Leach, 1815 and G. linearis , respectively. As a consequence, Scnipaeus was regarded most often as a synonym of Geophilus ( Meinert, 1870; Latzel, 1880; Sselivanov, 1881, 1884; Attems, 1903, 1929a; Crabill, 1954), or as a synonym of Clinopodes ( Brolemann, 1930) . Indeed, it was not cited as valid since Pocock (1901). Scnipaeus is recognized here as a junior synonym of Stenotaenia , as its type species is recognized as being identical to the type species of Stenotaenia [see Stenotaenia linearis ( Koch, 1835) ].

Simophilus Silvestri, 1896 . The genus Simophilus was introduced by Silvestri (1896) for the single species Geophilus frenum Meinert, 1870 , which thus is the type species by monotypy. Attems (1929b) described another species under this genus, namely Simophilus albanensis Attems, 1929 , and also moved Geophilus palaestinus Verhoeff, 1925 under it ( Attems, 1929a); the latter combination was not accepted in the subsequent literature. As the identity of both G. frenum and S. albanensis remained unclear, Simophilus continued to be cited as a genus of uncertain identity in all major works (Verhoeff, 1902–25, 1945; Brölemann, 1909a; Attems, 1929a, 1947). Occasionally, it was treated as a subgenus of Geophilus ( Verhoeff, 1941a) . Simophilus is recognized here as a junior synonym of Stenotaenia , as its type species is very similar to the type species of Stenotaenia [see Stenotaenia frenum ( Meinert, 1870) ], and deserves to be considered congeneric with it. Silvestri’s (1896) original diagnosis is fully compatible with the diagnosis of Stenotaenia provided here, even in major diagnostic traits such as the shape of the sternal pore areas and the last pair of legs.

Onychopodogaster Verhoeff, 1902 . Onychopodogaster was first introduced by Verhoeff (1902) only citing Onychopodogaster graecum [sic] as an alternative, ‘in litteris’ name for his new species Geophilus graecus . Onychopodogaster was explicitly used as a valid taxon in different publications (Verhoeff, 1902– 25, 1924a, 1925, 1928, 1934a, 1934b, 1937a, 1938, 1941a, 1943b, 1945; Brölemann, 1909b; Attems, 1926; Folkmanova, 1952). Therefore, as already discussed by Jeekel (2005), Onychopodogaster is an available name dating from 1902 (ICZN: art. 11.6; International Commission on Zoological Nomenclature, 1999), its author is Verhoeff (ICZN: art. 50.7), and its type species is Geophilus graecus Verhoeff, 1902 by monotypy (ICZN: art. 67.12). Onychopodogaster was not used as a valid taxon name after Folkmanova (1952); it was considered to be a synonym of Clinopodes Koch, 1847 , based on the unwarranted opinion of a close affinity of its type species with Clinopodes flavidus Koch, 1847 ( Brölemann, 1909a; Brolemann, 1930; Matic, 1972), or as a synonym of Geophilus Leach, 1814 ( Foddai et al., 1995), or was even completely ignored ( Attems, 1929a). Onychopodogaster is recognized here as a junior synonym of Stenotaenia , as its type species has been considered very close to the type species of Stenotaenia since it was introduced originally by Verhoeff (1902), and was later synonymized under Geophilus naxius Verhoeff, 1901 ( Verhoeff, 1925) , which is shown here to be congeneric with Stenotaenia linearis ( Koch, 1835) [see Stenotaenia naxia ( Verhoeff, 1901) ].

Insigniporus Attems, 1903 . The genus Insigniporus was introduced by Attems (1903) for his new species Insigniporus sturanyi , which is thus the type species by monotypy. The identity of this taxon has remained poorly understood, and different authors have proposed different affinities for it ( Attems, 1909; Brölemann, 1909a), yet its validity remained unchallenged, and another species, Insigniporus acuneli , was later described under it by Căpuşe (1968). Insigniporus is recognized here as a junior synonym of Stenotaenia because its type species is so close to the type species of Stenotaenia that it deserves to be included in the same genus. It is worth noting that I. acuneli is demonstrated here to be identical to S. linearis [see Stenotaenia linearis ( Koch, 1835) ]. Even the original diagnosis of Insigniporus is largely coincident with that of Stenotaenia , as revised here, in all characters that best differentiate the genus in respect to the other geophilids. The diagnosis of Insigniporus provided by Attems (1903, 1909, 1929a) departs from Stenotaenia only in two points, i.e. the putative presence of distinct labral sidepieces and the presence of a medial suture in the coxosternum of the second maxillae. However, direct examination of representative specimens of the type species Stenotaenia sturanyi ( Attems, 1903) demonstrated that the published accounts were inaccurate on these points [see Stenotaenia sturanyi ( Attems, 1903) ].

Notadenophilus Verhoeff, 1928. Notadenophilus was introduced by Verhoeff (1928) as a subgenus of Geophilus for his new species Geophilus (Notadenophilus) silvestrii , which is thus the type species by monotypy. No other species has ever been included in it, and Notadenophilus was indeed ignored by most authors, even though its taxonomic validity was never rejected explicitly. Notadenophilus is considered here to be a junior synonym of Stenotaenia because its type species is recognized as a junior synonym of Geophilus romanus Silvestri, 1895 , which clearly belongs to the genus Stenotaenia as diagnosed here [see Stenotaenia romana ( Silvestri, 1895) ].

Bithyniphilus Verhoeff, 1941 . The genus Bithyniphilus was introduced by Verhoeff (1941b) for the single species Bithyniphilus bosporanus , which is the type species by monotypy. Its identity has remained poorly understood, and indeed Zapparoli (1999) doubted its validity. So far, however, its taxonomic position has not been resolved. Bithyniphilus is recognized here as a junior synonym of Stenotaenia as its type species is very close to the type species of Stenotaenia [see Stenotaenia bosporana (Verhoeff, 1941) ], as explicitly admitted by Verhoeff (1945) in providing a detailed description of B. bosporanus . Furthermore, the peculiar traits given by Verhoeff (1941b, 1945) as being diagnostic are indeed fully compatible with the morphological variation of Stenotaenia , as are the apparent coalescence of the intermediate articles of the forcipules, the elongation of the sternal pore areas, and the aggregated pattern of the coxal pores.

Schizopleres Folkmanova, 1956 . The genus Schizopleres was introduced by Folkmanova (1956) for the new species Schizopleres giljarovi , which is thus the type species by original designation. No other species have since been included, and its status has remained undiscussed. Schizopleres is regarded here as a junior synonym of Stenotaenia , because its type species shares all the diagnostic characters of the genus with the type species of Stenotaenia , including all putative synapomorphies: above all, the shape of the labral margin, the conformation of the forcipules, the pattern of the sternal pores, and the pattern of the coxal pores. It is worth mentioning that Folkmanova (1956), in introducing Schizopleres , compared it with Clinopodes as well as with Insigniporus .

Euronesogeophilus Matic, 1972 . Euronesogeophilus was introduced by Matic (1972) as a subgenus of Nesogeophilus Verhoeff, 1925 to include two species, namely Geophilus ormanyensis Attems, 1903 , which he selected as the type species, and Geophilus palpiger Attems, 1903 . Euronesogeophilus was ignored by all subsequent authors, and was listed under the synonyms of Geophilus by Foddai et al. (1995). Euronesogeophilus is considered here as a junior synonym of Stenotaenia because its type species is synonymized here under G. linearis [see Stenotaenia linearis ( Koch, 1835) ].

Figures

Figure 1. Main differential characters between Stenotaenia and related genera to which species of Stenotaenia have been assigned, to date. Drawings represent the type species of each genus (see Table 1): A, forcipular segment, ventral; B, sternum at about one third of the length of the trunk, ventral; C, last leg-bearing segment and terminal segments in the female, ventral. Abbreviations: ch, chitin line; co, condyle of forcipular coxosternum; cs, ‘carpophagus’ socket; cx, forcipular coxosternum; fb, forcipular basal article; fi, forcipular intermediate articles; ft, forcipular tarsungulum; go, gonopods; lc, claw of last leg; ls, sternum of last leg-bearing segment; op, openings of coxal glands; pc, forcipular pleurocoxal margin; po, sternal pore area.