The fossil was found in the Saint Louis quarry situated to the north, northwest of Montceau-les-Mines city, in direction of Blanzy town, department of Saône-et-Loire (71), France (Charbonnier, 2014). The age, depositional conditions, and stratigraphy are also summarized in Charbonnier et al. (2008). This quarry was located between the quarries of La Sorme and St François, all in activity between 1975 and 1980, opened for coal extraction by the French company ‘les Houillères de Blanzy’. The coal level exploited was named ‘Couche n^o 1’. It is the top coal-level from the ‘Faisceau des grandes couches de l’assise de Montceau’ (figure and Log in Charbonnier, 2014). The insect is in a nodule from the ‘Couche à nodules’, situated at around 20 m above the last level of coal of the ‘Couche n^o 1’. This layer has yielded a lot of insects, crustaceans (Syncarida, Conchostraca), arachnids, fishes, tetrapods or bones of tetrapod, and plants. Although many insects were found in these nodules, comparatively few have been described or figured (Béthoux and Nel, 2010, Burnham, 1981, Burnham, 1983, Burnham, 1984, Burnham, 1985, Burnham, 1986, Burnham, 1994, Garwood et al., 2012, Langiaux, 1984, Langiaux and Parriat, 1974, Langiaux and Parriat, 1975a, Langiaux and Parriat, 1975b, Langiaux and Parriat, 1975c and Oudard, 1980).

The fossil specimen is preserved as a sub-tridimensional gently pyritized compression in a sideritic nodule. The specimen was observed under an Olympus SZX-9 stereomicroscope under film layer of ethyl alcohol. The venation pattern was drawn directly using a stereomicroscope with a camera lucida, and finally readjusted to the photograph scales using image-editing software (Adobe Photoshop). Photographs were made using an Olympus 5050 digital camera connected to the stereomicroscope.

We follow the wing vein nomenclature and systematics proposed by Storozhenko, 1998 and Storozhenko, 2002. Abbreviations of wing venation symbols throughout the text and the figures are given as: A, anal veins; CuA, cubitus anterior; CuP, cubitus posterior; MA, media anterior; MP, media posterior; RA, radius anterior; RP, radius posterior; Sc, subcosta posterior.

Order: Grylloblattodea Walker, 1914

Clade: Lemmatophorina Storozhenko, 1997

Family: Euryptilonidae Martynov, 1940

Montceaupterum gen. n.

Type species: Montceaupterum baillyi sp. n., by monotypy.

Etymology. Named after Montceau-les-Mines and ‘pterum’ for wing. Gender masculine.

Diagnosis. Characters concern forewing only: clear division of CuA into well-defined CuA1 and CuA2; CuA1 with broad distal area and three long branches ending on posterior wing margin; CuA1 touching median vein in one point; area between CuP and CuA basally broadened; Sc not ending on radius in distal part of wing; RP probably with few distal branches; MA simple; MP distally forked into two simple branches.

Montceaupterum baillyi sp. n.

(Fig. 1, Fig. 2, Fig. 3 and Fig. 4)

Etymology. Named after Mr Maurice Bailly, who discovered this fossil, 35 years ago.

Locus typicus and stratum typicum. Gzhelian, Late Pennsylvanian, Upper Carboniferous (Charbonnier et al., 2008), sideritic concretion outcrop of Saint Louis quarry, Montceau-les-Mines, France.

Material. Holotype specimen JMP.365.B (thorax with remnants of at least three wings visible, coll. Bailly), housed in the private collection of Jean-Marc Pouillon.

Remark. This specimen was figured in Langiaux (1984: 195, fig. 317), as an undetermined Insecta ‘forme 6’.

Diagnosis. As for the genus.

Description. Head, abdomen, and legs not preserved. Pronotum rounded, 1.5 mm long and 1.7 mm wide, with an anterior narrow depressed zone, 0.3 mm long and 1.6 mm wide; pronotum divided into two parts by a median furrow; two lateral lunular membranous extensions showing traces of rudimentary veins, 1.0 mm wide and 2.0 mm long, possibly attached to pronotum in one point (Fig. 2); mesothorax partly visible, showing two rounded dark depressions, 1.0 mm apart, possibly corresponding to insertions of mid coxae.

Wings (Fig. 3 and Fig. 4) covering posterior part of body as a roof; length of forewing fragment ca. 11.0 mm, probable total length ca. 13.6 mm, width in widest part 5.0 mm; costal area 1.0 mm wide, rather broad in middle of wing, bearing 13 preserved crossveins, all simple; Sc straight, apically deflected but probably reaching costal margin 4.0 mm from edge of wing; R not really straight, RA and RP separating at about approximately midway of wing length from base, 5.8 mm from wing base; RA simple and straight; area between RA and RP with numerous crossveins (seven of them being preserved); stems of M and R very close running parallel for a short distance, area between M and radius basal of RP poorly preserved so that the possible crossveins are not visible; M divided into MA and MP 2.3 mm basal of separation of RA and RP; MA simple, nearly straight, not approximating RP; area between RP and MA numerous crossveins (five of them being preserved); base of MP ca. 8 mm from wing base, bifurcated about mid-wing and reaching posterior wing margin with two branches; MP area narrow with seven preserved crossveins between MA and MP; CuA basally strongly diverging from CuP towards M, connected to it for 0.3 mm, and with two basal branches CuA1 and CuA2; CuA1 divided into three distal branches; CuA2 simple; CuP simple and nearly straight; area between CuA and CuP with one row of large transverse cells; anal area poorly preserved but with simple straight A1 and fragments of A2 visible.

Following the key to the “grylloblattodean” families of Storozhenko (1998: 65–67), it is quite delicate to discriminate among several families because one crucial node number ‘20(59)’ of this key concerns the ‘clear division of CuA into well-defined CuA1 and Cu2’ versus ‘CuA not clearly divided into CuA1 and CuA2’. It is supposed to discriminate between the Euryptilonidae Martynov, 1940 (supposed to have no clear division of CuA) and the Pinideliidae Storozhenko, 1997 for instance (supposed to have a clear division of CuA). But the euryptilonid genus Oborella Kukalová, 1964 and the pinideliid genus Pinidelia Storozhenko, 1994 both have a well-defined CuA2 (Storozhenko, 1998: figs 150 and 240). Therefore, it is quite delicate to use this key.

Nevertheless, this fossil has important diagnostic characters of the Euryptilonidae, and more precisely with the genus Oborella Kukalová, 1964, i.e. pronotum with broad membranous lateral extensions and an anterior transverse zone; costal area rather narrow with simple crossveins; Sc not ending on radius but on costa; RP with few distal branches; MA simple; MP with a distal fork into two simple branches; CuA1 with distal fork(s); CuA2 well-defined and simple; area between CuP and CuA basally broadened; CuA touching median vein in one point; crossveins simple (Prokop et al., 2012 and Storozhenko, 1998). We compare our fossil to the different euryptilonid genera as listed in Storozhenko (1998).

Montceaupterum gen. n. differs from Euryptilon Martynov, 1940 and Karaungirella Storozhenko, 1991 in the shape of CuA divided into CuA1 and CuA2 instead of being anteriorly pectinate. Note that Euryptilon cuculiophoris Aristov, 2002 is based on a very poorly preserved specimen with only fragments of forewing veins preserved (Aristov, 2002). It shares with Stereopterum Carpenter, 1950 the division CuA1–CuA2, but its CuA and M are not fused for a long distance, unlike in Stereopterum and Karaungirella. Quercopterum Kukalová, 1964, Maculopterum Kukalová, 1964, Villopterum Kukalová, 1964, and Oborella have also a clear CuA2 but CuA1 defines a reduced area unlike Montceaupterum. Sharovipterum Kukalová, 1964 has a shorter Sc than Montceaupterum, ending on costal margin three cells distal of base of RP. Only Torrentopterum Kukalová, 1964 has a CuA2 well-defined and CuA1 defining a broad distal area with three long branches of CuA1 ending on posterior wing margin. Nevertheless, it differs from Montceaupterum in the MP simple. Lastly the genus Stereosylva Aristov, 2002, originally attributed to the Euryptilonidae, was later transferred into the Soyanopteridae Aristov and Rasnitsyn, 2011 (Aristov and Rasnitsyn, 2011).

The Euryptilonidae are currently recorded only in the Permian (Storozhenko, 1998), thus the Late Carboniferous Montceaupterum can be considered as the oldest record of the family.