Isoscelipteron bertrandi, Boderau & Ngo-Muller & Nel, 2024

Boderau, Mathieu, Ngo-Muller, Valerie & Nel, André, 2024, First representatives of the stonefly genus Perlomyia and the beaded lacewing genus Isoscelipteron from the Upper Miocene of France (Plecoptera: Leuctridae and Neuroptera: Berothidae), with biogeographical considerations, Zootaxa 5481 (1), pp. 131-140 : 136-137

Isoscelipteron bertrandi sp. nov.

urn:lsid:zoobank.org:act:A122D4A3-1FED-400A-863F-D107AB4D4A6C

Fig. 5

Material. Holotype IF-STR-0105 (a forewing), provisionally housed in the Muséum National d’Histoire Naturelle , Paris, France.

Etymology. Named after Mr Guilhem Bertrand, for the great help he provided in our field research in the Quarry of Sainte Reine.

Locality and horizon. Latest Miocene, diatom paleomaar, Sainte-Reine (quarry of Foufouilloux, Virargues village), near Murat, Cantal, France.

Diagnosis. Forewing characters only. Concavity of postero-distal margin present but not strongly pronounced; 10 posterior branches of RP; line of gradate crossveins making an angle of ca. 20° with the main stem of RP; CuA and CuP with numerous very long parallel branches

Description. A nearly complete forewing, with area between C and R/RA missing; membrane brow, main veins white, and gradate crossvein black; wing 13.3 mm long, ca. 4.5 mm wide; apex of wing pointed; postero-distal margin weakly but distinctly falcate; RP with 10 posterior branches; inner gradate series of crossveins complete, in a weakly curved line making an angle of ca. 20° with the main stem of RP; no outer gradate series of crossveins; MP with two main forks and several long apical branches; CuA and CuP with numerous long parallel branches.

Remark. The acute wing apex, the falcate postero-distal margin of this forewing plus the wing densely covered with setae support an attribution to the Berothidae : Berothinae. Within this subfamily, only some species of the genus Isoscelipteron have 10 branches of RP or more, as in the new fossil (Navás 1929; MacLeod & Adams 1967; Aspöck & Aspöck 1981, 1984a,b, 1985a,b, 1986, 1987, 1988a,b,c, 1989, 1991; Smithers 1984; Adams 1989; Penny & Winterton 2007; Machado et al 2022). These are Isoscelipteron borneole Aspöck & Aspöck, 1991 , Isoscelipteron philippinicola Aspöck & Aspöck, 1991 , and Isoscelipteron fulvum Costa, 1863 ( Aspöck 1987; Aspöck & Aspöck 1991), while the other species have at most eight branches of RP. The new fossil and Isoscelipteron fulvum differ from Isoscelipteron borneole and Isoscelipteron philippinicola in the clearly less pronounced concavity of the postero-distal margin of their forewings ( Aspöck & Aspöck 1991: fig. 12).

The new fossil differs from I. fulvum in the line of gradating crossveins making an angle of ca. 20° with the main stem of RP vs. ca. 40° in the latter. Additionally, CuA and CuP have numerous very long parallel branches, similar to the situation in I. borneole , but unlike in I. fulvum ( Aspöck & Aspöck 1991: fig. 14). We propose to assign the fossil into a new species in Isoscelipteron .

Figures

FIGURE 5. Isoscelipteron bertrandi sp. nov., holotype IF-STR-0105. Photograph of forewing. Scale bar = 2 mm.