Moderate-sized earwigs, with numerous setose and distinctively sculptured (densely punctate-granulose throughout, particularly on head and thorax). Head broad, nearly as wide as anterior border of pronotum, posterior margin nearly straight. Antenna with 20 antennomeres; scape robust and slightly broader than remaining antennomeres; pedicel slightly longer than wide; all flagellomeres longer than wide. Compound eyes large and situated at posterior temples; ocelli absent. Dorsal surface without Y-shaped ecdysial cleavage scar. Pronotum approximately oval, anterior and posterior margins subequal in width, lateral margin convex and rounded. Tegmina without longitudinal veins; tegmina and squamata covering abdominal segment II. Legs with abundant short setae; femora carinulate; all tarsi pentamerous (i.e., tarsal formula 5-5-5 rather than the 4-4-5 of some genera); pretarsal claws simple. Female with exposed ovipositor. Pygidium small. Cerci filiform and long, with about 30 cercomeres.

The generic name is a combination of the Greek prefix a– (ᾰ–, alpha privativum designating negation), neûron (νεῦρον, meaning, “nerve”), and dérma (δέρμᾰ, genitive dérmatos, meaning, “skin” – an allusion to the leathery tegmina and from which the ordinal name is derived, Dermaptera literally meaning, “skin wings”), referencing the absence of tegminal venation, a rare feature among Archidermaptera. The gender of the name is neuter.

As for the genus (vide supra).

Holotype, a completely preserved female, CNU-DER-NN2021003C/P; paratype, CNU-DER-NN2021004C/P. All type material deposited in the College of Life Sciences, Capital Normal University, Beijing, China.

Jiulongshan Formation (Middle Jurassic); Daohugou Village, Wuhua Township, Ningcheng County, Inner Mongolia, China.

Adult female, preserved in both dorsal and ventral aspects. Body with numerous setae and distinctively sculptured (densely punctate-granulose throughout, particularly on head and thorax). Total length as preserved (excluding antennae, ovipositor, and cerci) about 10.75 mm. Head medial length from clypeal apex to posterior border 1.57 mm, maximum width (across level of compound eyes) 1.56 mm, prognathous; maxillary palpus pentamerous, ca 1.33 mm long (Fig. 1E). Antennal length 5.2 mm, with 20 elongate antennomeres; scape thick, broader than remaining antennomeres, longer than wide, length 0.31 mm, apical width 0.22 mm; pedicel shortest, length 0.17 mm; flagellomeres longer than wide and distally becoming tapered. Compound eyes large and prominent, located near posterior margin of head, compound eye length 0.72 mm; distance between compound eyes distinctly longer than compound eye length (Fig. 1E). Ocelli absent. Pronotum approximately oval and almost as broad as posterior margin of head, medial length 1.12 mm, maximum width 1.71 mm; anterior margin 1.56 mm wide, posterior margin 1.53 mm wide, anterior margin nearly straight, posterior margin slightly convex and lateral margins convexly rounded. Tegmina well developed, without venation, length 2.41 mm, maximum width 1.39 mm, lateral margins arc-shaped, posterior margins truncate, squamata extending well beyond tegminal apex, tegmina and squamata covering abdominal terga I and II (Fig. 1C). Femora compressed and ventrally carinulate; tibiae elongate, slender, almost as long as femora; all tarsi pentamerous (Fig. 2D). Pretarsal claws present and simple; arolium absent (Fig. 1D). Abdomen cylindrical, with dense, soft, short setae, lateral margins relatively convex, almost all segments wider than long with apical margins straight, abdominal length as preserved (excluding cerci) 5.38 mm, maximum width 2.41 mm. Abdomen distally with external ovipositor, length 1.64 mm. Pygidium small. Cerci 5.33 mm long, longer than one-half abdominal length, with ca 30 elongate cercomeres, margins with abundant short setae.

Figure 1. 

Holotype of Aneuroderma oiodes gen. et sp. nov. CNU-DER-NN2021003C. A Photograph of dorsal aspect B line drawing of dorsal aspect C dorsal view of tegmina and squamata of hind wings D anterior lateral (prolateral) view of right midleg E dorsal aspect of head. Scale bars: 2.0 mm (A, B); 0.5 mm (C, D, E). The tegmina and squamata of the hind wings in C, the right midleg in D, and the head in C are photographed under ethanol.

The specific epithet is the Greek neuter adjective ōiôdes (ᾠῶδες, meaning, “oval” or “egg-like”), as a reference to the ovoid pronotum.

The new genus is placed within Protodiplatyidae on the basis of the characteristic filiform antenna with 17–23 antennomeres; pedicel and flagellomere I subequal in size; pentamerous metatarsus; cerci elongate, slender, and multimerous; and externalized ovipositor in females.

Figure 2. 

Holotype of Aneuroderma oiodes gen. et sp. nov. CNU-DER-NN2021003P. A Photograph of ventral aspect B ventral view of head C line drawing of ventral aspect D ventral view of midleg and hindleg. Scale bars: 2.0 mm (A, C); 0.5 mm (B, D). The head in C and the right midleg and hindleg in D are photographed under ethanol.

Key diagnostic characters of Aneuroderma gen. nov. are summarized in Table 2 and compared with those of nine genera of Protodiplatyidae. Aneuroderma gen. nov. can be distinguished from Archidermapteron Vishniakova, 1980 by the posterior margin of head as wide as anterior border of pronotum, 20 antennomeres, tegmina without longitudinal veins, and hind wings extending to apex of abdominal segment II, pygidium small, 30 cercomeres, and a cercus/body ratio of 0.5. By contrast, Archidermapteron has the head narrower than the pronotum, the tegmina with longitudinal veins, hind wings extending beyond abdominal segment IV, pygidium transverse and trapeziform, and 40 cercomeres that together are slightly shorter than the body. Aneuroderma gen. nov. differs from Longicerciata Zhang, 1994 by the latter with the head broader than the pronotum, 26 antennomeres, at least 36 cercomeres, and a cercus/body ratio of 1. Aneuroderma gen. nov. differs from Barbderma Xing et al., 2016a in the number of antennomeres (20 instead of 19), and the hind wings extending to the apex of abdominal segment II, instead of segment I. Aneuroderma gen. nov. is similar to Asiodiplatys Vishniakova, 1980 in that the tegmina lack longitudinal veins and the hind wings extend to the apex of abdominal segment II, but the former differs from the latter in only 20 antennomeres (vs. 22 antennomeres), the posterior margin of the pronotum straight (vs. pronotum with shallow, broad notch anteriorly), and 30 cercomeres (vs. 40 cercomeres). Aneuroderma gen. nov. can be separated from Abrderma Xing et al., 2016b, Microdiplatys Vishniakova, 1980, Perissoderma Xing et al., 2016b, and Protodiplatys Martynov, 1925, by the following traits: (1) absence of longitudinal veins in tegmina (present in the aforementioned genera), and (2) 20 antennomeres (vs. 17 to 19 in the other genera). The new genus is readily differentiated from Sinoprotodiplatys Nel et al., 2012 by the posterior margin of the head and anterior border of the pronotum equal in width (head narrower than pronotum in the latter), 20 antennomeres, and 30 cercomeres (18 antennomeres and 20 cercomeres in the latter). Lastly, the distinctive punctate sculpture of the new genus is quite distinctive among several Archidermaptera.

Figure 3. 

Paratype of Aneuroderma oiodes gen. et sp. nov. CNU-DER-NN2021004C/P. A Photograph of dorsal aspect B photograph of ventral aspect. Scale bars, 2.0 mm (A, B). The body in A and B are photographed under ethanol.

[modified from Zhang (2002)]. Moderate-sized earwigs, with short and fine pubescence; head triangular, length subequal to width, mandibles denticulate; antenna filiform, with at least 19 antennomeres (as noted by Zhang (2002)), scape stout and enlarged, pedicel rather small, clearly shorter than scape and flagellomere I; ocelli present; neck prominent, divided into anterior and posterior cervical sclerites (‘blattoid’ neck arrangement). Pronotum transverse, broader than long and about as broad as head. Femora compressed and ventrally carinulate; all tarsi pentamerous, shorter than tibiae; pretarsal claws well developed and bearing broom-shaped arolia. Procoxal cavities positioned close to each other; mesocoxal cavities remote, metacoxal cavities elongate transversely and moderately separated. Tegmina with longitudinal veins strongly developed, main veins of Sc, R, M, and Cu present. Female with a pair of elongate valvulae entirely exposed. Cerci flexible, long, filiform, and multimerous.

Included species. Aside from the type species, the genus currently includes S. concavum Xiong, Engel & Ren, sp. nov. (infra).

The new species can be distinguished from the type species, Sinopalaeodermata neimonggolense (note that the name Sinopalaeodermata is neuter, not feminine, as dérmata is the neuter nominative plural of dérma; and given that the specific epithet is adjectival it must still agree in gender with the generic name) by the relatively straight apical margin of the penultimate sternum (in S. neimonggolense the penultimate sternum has a concave margin); the roughly reniform pronotum, with the anterior margin concave medially the posterior margin weakly convex, and lateral margins rounded (in S. neimonggolense the pronotum is approximately rectangular, with the anterior margin almost as wide as the posterior margin, and the lateral margins relatively straight and parallel to each other); the tegmina with a more pronounced concave arc marginally at the apex of Rs (in S. neimonggolense the margin is more sloping rather than deeply concave); and M does not extend to near the apex of CuA , with CuP terminating more proximal to CuA (even before the tangent with M) (in S. neimonggolense M terminates more proximally and CuP extends to the apex of CuA).

Holotype. A completely preserved female, CNU-DER-NN2021005C/P, deposited in the College of Life Sciences, Capital Normal University, Beijing, China.

Jiulongshan Formation (Middle Jurassic); Daohugou Village, Wuhua Township, Ningcheng County, Inner Mongolia, China.

Adult female, preserved in both dorsal and ventral aspects. Total length as preserved (excluding antennae, cerci, and valvulae) about 18.02 mm. Body with sparse pubescence and punctate. Head medial length from clypeal apex to posterior border 2.08 mm, maximum width (across level of compound eyes) 2.27 mm, triangular. Compound eye large, ovate, located near posterior margin of head; compound eye length 0.91 mm; width between compound eyes 2.58 mm. Ocelli comparatively small. Cervix with large anterior and posterior cervical sclerites, anterior sclerite slightly larger than posterior sclerite. Pronotum approximately reniform, medial length 1.46 mm, maximum width 2.58 mm, anterior width 1.64 mm, posterior width 2.07 mm, anterior margin concave and posterior margin arched, lateral margins convexly rounded. Mesoscutellum large, elliptical, entirely exposed. Tegmina present, not truncated, length 6.73 mm, maximum width 2.55 mm, with medially sinuate anterior (lateral) margin and straight posterior (mesal) margin. Veins simple, Rs curved anterior margin, fading out just before margin; M simple, basally and apically straight, gently curved medially; Cu with two branches (CuA and CuP), CuP terminates proximal to CuA; A1 and A2 simple and straight, running parallel to each other and posterior margin, terminating apically (Fig. 4C). Femora compressed and ventrally carinulate (Fig. 4D); tibiae elongate, slender, and almost as long as femora; tarsi pentamerous, tarsomere IV slightly extending under base of tarsomere V (Fig. 5C). Pretarsal claws present but not well preserved. Abdominal length as preserved (excluding cerci) 9.75 mm, maximum width 3.52 mm; all segments distinctly wider than long, lateral abdominal margins gently convex. Pygidium not evident. Ovipositor exposed, 2.84 mm long. Cerci as preserved only 2.9 mm long, with segments but not clearly preserved.

Figure 4. 

Holotype of Sinopalaeodermata concavum sp. nov. CNU-DER-NN2021005C. A Photograph of dorsal aspect B line drawing of dorsal aspect C dorsal view of right tegmen D anterior lateral (prolateral) view of left midleg. Scale bars: 4.0 mm (A, B); 0.5 mm (C, D).

Figure 5. 

Holotype of Sinopalaeodermata concavum sp. nov. CNU-DER-NN2021005P. A Photograph of ventral aspect B line drawing of ventral aspect C ventral view of right midleg and tegmen. Scale bars: 4.0 mm (A, B); 1 mm (C).

The specific epithet is taken from the Latin adjective concavus (meaning, “concave”), in reference to the more pronounced concave margin to the tegmina relative to the type species.