Perissoderma triangulum Xing, Shih & Ren, sp. nov.

Perissoderma triangulum Xing, Shih & Ren sp. nov.

(Fig. 2)

Diagnosis. As for the genus due to monotypy.

Etymology. The specific name refers to the shape of head.

Type locality and horizon. Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China; Jiulongshan Formation, the latest Middle Jurassic (late Callovian).

Holotype. CNU-DER-NN2016001, adult female, well-preserved and nearly complete (Fig. 2), housed in the Key Lab of Insect Evolution & Environmental Changes, the College of Life Sciences, Capital Normal University (CNUB), Beijing.

Description. An adult female, dorsal and ventral aspect. Body medium-sized (excluding antenna and cercus), 15.7 mm long, covered with pubescence.

Head 1.5 mm long, 2.1 mm wide, subtriangular. Neck divided into anterior and posterior cervical sclerites, with anterior margin longer than posterior. Ocelli present. Compound eye large, prominent and located near posterior margin of head. Mandible with two apical teeth, other teeth not visible. Left maxillary palpus only with the first 2 segments preserved, right palpus 2 segments preserved. Labrum semicircular with posterior margin straight. Clypeus approximately rectangular, 1.1 mm long, 0.1 mm wide. Antenna 6.6 mm long with 17 elongate antennomeres; scape broader than other antennomeres; flagellomeres longer than wide, distally becoming small and orbicular.

Pronotum approximately elliptical, 1.4 mm wide, 2.3 mm long; anterior margin 2.1 mm wide, posterior margin 1.7 mm wide; both margins convex; lateral margins rounded; width ratio of anterior margin/posterior margins 1.2. Scutellum not present.

Tegmen with longitudinal veins strongly developed, 5.9 mm long, 1.6 mm wide (ratio 3.7); costal margin slightly arched, sutural margin straight, posterior margin apical. Hind wing covered by tegmen and extending slightly beyond the third abdominal segment.

Abdomen 6.9 mm long, 2.4 mm wide; eight abdominal segments; cercus as preserved 8.6 mm long, length ratio of cercus/body 0.55, with segments but not clearly preserved. Abdomen distally with external ovipositor, 1.8 mm long, slot present at the middle. Pygidium small.

Fore femur thick and short, 0.9 mm long, 0.7 mm wide. Middle femur 1.2 mm long, 0.5 mm wide. Hind femur 2.2 mm long, 0.7 mm wide. All tibiae subcylindrical; tarsal segments not clearly preserved.

TABLE]. List of đescribeđ Archiđermaptera fossils.

Family Name of species Locality Geological age Length ratio of cercus/body; number

of cercal segments]

Protođiplatyiđae Archidermapteron martynovi Vishniakova, 1980 Kazakhstan Late Jurassic About 0.7; N/A Abrderma gracilentum Xing, Shih & Ren gen. et sp. nov. China Miđđle Jurassic About 0.2; N/A Asiodiplatys speciosus Vishniakova, 1980 Kazakhstan Late Jurassic About 0.4; N/A Brevicula gradus Whalley, 1985 Englanđ Early Jurassic About 0.25; N/A Microdiplatys campodeiformis Vishniakova, 1980 Kazakhstan Late Jurassic About 0.95; N/A Microdiplatys oculatus Vishniakova, 1980 Kazakhstan Late Jurassic About 0.5; N/A Microdiplatys perfectus Vishniakova, 1985 Russia Miđđle Jurassic N/A

Protodiplatys fortis Martynov, 1925 (Martynov 1925a) Kazakhstan Late Jurassic About 0.15; N/A Protodiplatys gracilis Vishniakova, 1980 Kazakhstan Late Jurassic N/A

Protodiplatys mongoliensis Vishniakova, 1986 Mongolia Early Cretaceous N/A

Sinoprotodiplatys zhangi Nel, Garrouste &Waller, 2012 China Early Cretaceous About 0.8; about 20 segments. Sinoprotodiplatys ellipsoideuata Xing, Shih & Ren,2016 China Early Cretaceous About 0.7; N/A Barbderma oblonguata Xing, Shih & Ren, 2016 China Early Cretaceous About 0.42; N/A Perissoderma triangulum Xing, Shih & Ren, gen. et sp. nov. China Miđđle Jurassic About 0.55; N/A Longicerciata mesozoica Zhang, 1994 2 China Early Cretaceous About 1; more than 36 segments. Longicerciata rumpens Zhang, 1994 2 China Early Cretaceous N/A

Turanoviiđae Turanovia incomplete Vishniakova, 1980 Kazakhstan Late Jurassic About 0.2; N/A

Dermapteriđae Palaeodermapteron dicranum Zhao, Shih & Ren, 2011 China Miđđle Jurassic About 0.15; with 5 segments Engel (2003) anđ Engel & Haas (2007) synonymizeđ Longicerciatiđae Zhang, 1994 with Protođiplatyiđae.