Aspidothorax hispanicus, Santos & Hernández-Orúe & Peñalver & Mcloughlin & Diez & Nel, 2025

Santos, Artai A., Hernández-Orúe, Antonio, Peñalver, Enrique, Mcloughlin, Stephen, Diez, José B. & Nel, André, 2025, First Iberian aspidothoracid megasecopteran insect and associated plants evidencing herbivory in a tropical Carboniferous forest from León, Spain, Acta Palaeontologica Polonica 70 (1), pp. 115-124 : 117-120

Aspidothorax hispanicus sp. nov.

Fig. 2 .

Zoobank LSID: urn:lsid:zoobank.org:act:.

Holotype: MUPE-IWC-01, well-preserved distal two-thirds of a wing co-preserved with Alethopteris zeilleri and Pseudomariopteris cordato-ovata plant fragments.

Type locality: Outcrop near Carmen mine, La Magdalena Coalfield, León Province, Spain ( Fig. 1 ).

Type horizon: Un-named “Saberian”, Gzhelian, upper Carboniferous beds.

Diagnosis. —Wing characters only. RP with four branches; CuP and MP veins each with long fork; area between PCu and posterior wing margin broad, with five–six rows of cells in-between.

Description. —Wing hyaline except for darkened costal area, apex, and small spots at forks of RP, MP, and CuP; wing apex pointed; preserved part 29.6 mm long, wing 10.2 mm wide; costal area very narrow, 0.2 mm wide; ScP close to R/RA and terminating at C 8.5 mm from wing apex; R/ RA weakly curved, with apical part of area between it and C slightly widened, with few weak and short crossveins; base of RP 22.5 mm from wing apex; RP posteriorly pectinate, with four main branches, all simple; base of M 26.9 mm basal to that of RP; base of MA 3.6 mm distally; RP and MA touching at one point near base of RP; MA simple, MP with two long branches; a strong crossvein m-cua between base of M and CuA; CuA simple; bases of CuA and CuP not preserved; CuP with two long branches; PCu posteriorly pectinate, with four branches preserved; five–six rows of cells between PCu and posterior margin of wing.

Remarks.—The new insect fossil is similar to the wings of megasecopterans belonging to Aspidothoracidae Handlirsch, 1919 , and Bardohymenidae Zalessky, 1937 . Owing to the lack of phylogenetic analyses of Megasecoptera , we compare the new fossil with all megasecopteran families.

Representatives of Protohymenidae Tillyard, 1924 , have a very narrow area between C and RA and a very distinctive posterior branch of RA near its apex ( Huang et al. 2021), unlike the new fossil. Mischopteridae Handlirsch, 1906 , Foririidae Handlirsch, 1919 , and Aspidohymenidae Martynov, 1930 , have distinctive wing shapes, and the distal crossveins are arranged in several lines as in extant Chrysopidae (or- der Neuroptera ). Representatives of Moravohymenidae Kukalová-Peck, 1972 , have a broader area between RA and RP than the new fossil, and MA, MP and branches of RP slightly curve anteriorly in their distal portion. Anchineuridae Carpenter, 1963 , Hanidae Kukalová-Peck, 1975 , Caulopteridae Kukalová-Peck, 1975 , Arcioneuridae Kukalová-Peck, 1975 , Engisopteridae Kukalová-Peck, 1975 , and Ancopteridae Kukalová-Peck, 1975 , have many more veins and crossveins than the new fossil ( Kukalová-Peck 1975, 1991a). Members of Alectoneuridae Kukalová-Peck 1975 , have MA touching RP at only one point ( Carpenter 1963; Kukalová-Peck 1975). Scytohymenidae Martynov, 1937 , Aykhalidae Sinitshenkova, 1993 , Sphecopteridae Carpenter, 1951 , Brodiopteridae Carpenter, 1963 , and Brodiidae Handlirsch, 1906 , have a relatively simplified venation with very few crossveins ( Carpenter 1992; Pecharová et al. 2015a; Prokop et al. 2017). Representatives of Xenopteraidae Ross et al. 2013 (replacement name for Xenopteridae Pinto, 1986 ) have a MA connected to RP ( Pinto 1986; Pecharová et al. 2015b). Vorkutiidae ( Vorkutia Rohdendorf, 1947 , Siberiohymen Rohdendorf, 1961 , and Fragmohymen Novokshonov, 1995 ) seem to constitute a composite group with taxa having varied venation styles, based on incomplete wings. Nevertheless, they all differ from the new fossil by the ScP ending in RA at the midwing ( Rohdendorf 1947, 1961; Novokshonov 1995). Corydaloididae Handlirsch, 1906 ( Corydaloides Brongniart, 1885 ), Sphecorydaloididae Pinto, 1994 ( Sphecorydaloides Pinto, 1994 ) and Ischnoptilidae Carpenter, 1951 ( Ischnoptilus Brongniart, 1894 ) have a MA that anastomoses with RP, and a CuA anastomosing with M for some distances, unlike in the new fossil.

The new fossil shares with Aspidothoracidae and Bardohymenidae the characters of vein MA not touching RP and CuA not touching M. Pecharová et al. (2020: 10) proposed the following emended diagnosis for Aspidothoracidae : “The fore and hindwings homonomous, venation nearly the same, wings narrowing gradually basally, not petiolate. The apex distinctly pointed. ScP terminates near RA. ScP and RA very close together, connected to costal margin; stem of M very close to, but separate from base of RA + RP; MA free from RP and not diverging towards it, connected by strong cross vein rp-ma; stem of Cu basally very close to M, but not connected to it; CuA not diverging towards MP, connected by a strong cross vein (m-cua); one anal vein A1 [PCu]. Cross veins numerous and nearly evenly distributed over the wing”. All the preserved characters of the new fossil conform well to this diagnosis, except for the presence of a strong crossvein rp-ma.

Pecharová et al. (2020: 2) proposed the following emended diagnosis for the Bardohymenidae : “Fore and hind wings subequal in length and shape (nearly homonomous), petiolate, similar in venation; CA+CP flattened and wide, running close to ScA+ScP (costal space narrow); ScP distinguishable as a separate vein only in proximal part of wing; distally continues along RA, RA connected with CA+CP and ScA+ScP except in the distal part of wing; RA diverging from CA+CP + ScA+ScP and forming an apical cell; RP originating at about midwing, gives rise to 2–5 branches, M lies close to RA+RP basally, but separate from it, diverging away from RA+RP in the second quarter of wing; M dividing into simple MA and MP near to the point at which RP separates from RA; MA connected to RP by a strong cross vein; Cu at the base connected with the stem of M; CuA connected to M by a strong cross vein, one long anal vein with posterior branches; cross veins usually arranged in 2 staggered rows”.

The new fossil shares the presence of more crossveins not arranged in two rows with Aspidothoracidae , in contrast to all taxa of Bardohymenidae . However, it shares the character of area between C and RA broadened apically and having some very short intervening crossveins with Bardynohymenidae. This broadening is similar to that of Aspidothorax triangularis Brongniart 1894 , but is much weaker in the new fossil than in all Bardohymenidae ( Pecharová et al. 2020: fig. 7). Thus, we assign the new fossil to Aspidothoracidae . Aspidothorax permianus differs from the new fossil in its simple CuP and MP vs with a long fork ( Sinitshenkova et al. 2020). Aspidothorax triangularis differs from the new fossil in having a narrower area between PCu and the posterior wing margin, with one–two rows of intervening cells vs five–six ( Carpenter 1992).

Stratigraphic and geographic range.—Known only from type locality and horizon.

Figures

Fig. 2. Aspidothoracid megasecopteran insect Aspidothorax hispanicus sp. nov. holotype (MUPE-IWC-01) from mine heap near Carmen mine, La Magdalena Coalfield, León Province, Spain, “Saberian”: Gzhelian; A1, photography of the specimen, note fossils of the gymnosperm Pseudomariopteris cordato-ovata (Weiss, 1869) Gillespie et al., 1978 ex Krings et Kerp, 2000, with evidence of herbivory; A2, line drawing of wing venation.

Fig. 1. Geological sketch map showing the La Magdalena Coalfield (León Province, NW Spain) and other coalfields previously yielding Carboniferous Megasecoptera in the northwestern Iberian Peninsula (see Table 1 for previous records).