Aristoviidae Storozhenko & Gröhn, 2023

STOROZHENKO, SERGEY YU. & GRÖHN, CARSTEN, 2023, A new family of grylloblattids (Insecta: Grylloblattida) from mid-Cretaceous Burmese amber, Palaeoentomology 6 (2), pp. 165-173 : 166

Family Aristoviidae Storozhenko & Gröhn fam. nov.

Type genus. Aristovia gen. nov., here designated.

Diagnosis. The new family is most similar to the Early Permian–Middle Triassic Megakhosaridae and the Middle Permian–Middle Jurassic Blattogryllidae in the large head with relatively large compound eyes and three small ocelli, filiform multi-segmented antennae, orthopteroid mouthparts, 5-segmented tarsi, and wing venation, but differs from both by lacking the paranotalia (lateral expansions of the pronotum) and by Sc ending on RA near the apex in both fore- and hind wings. In Megakhosaridae and Blattogryllidae , the ring of paranotalia is always present and Sc ends in C. The new family is also similar to the wingless Grylloblattidae but easily recognizable from it by the lack of the strong transverse furrow separating the anterior part of pronotum from its posterior part, the character typical for all known extant species of Grylloblattidae .

Description. Medium sized insects ( Fig. 1A, B ), length of body (from apex of mandibles to apex of wings) 25 mm.

Head large ( Figs 2A , 4A ); cranium (length = 2.7 mm, width = 3.0 mm) about 1.2 times as wide as the pronotum, without setae; compound eyes large, oval; ocelli moderately large. Antennae filiform with at least 25 antennomeres; scapus widest, pedicel narrower than scapus; segments of flagellum narrow, 5.5–6.2 times as long as wide. Mouthparts orthopteroid. Mandibles (length 1.6 mm) highly sclerotized, asymmetrical; inner side of right mandible with a strong preapical tooth; left mandible with two small teeth near the middle. The distal part of maxillae extends past the top of the mandibles; galea sickle-shaped; lacinia as long as mandible, curved, its inner side without preapical teeth and a row of setae near the base ( Fig. 4B ); maxillary palp 5-segmented, 1st segment short, other segments elongated, 5th segment longest, about 7.5 times as long as wide, with pointed apex.

Pronotum 1.25 times as long as wide with broadly rounded posterior margin; paranotalia, the transverse sulcus at the anterior margin, the median longitudinal suture, and setae absent.

Forewing ( Fig. 3C ). Membranous, 16.9 mm long, 3.4 times as long as wide; crossveins present between main veins. Sc ending on RA near the apex of wing. Subcostal area narrow. RA simple, almost straight, parallel to Sc, ending on the anterior wing margin. RA/RS fork slightly after the basal fourth of wing length; RS posteriorly pectinate, with four branches. Area between anterior wing margin and Sc and Sc–RA area slightly narrower than RA–RS area. The base of M absent. MA diverges from CuA in the basal fifth of the wing length, apically with short fork. MP diverges from CuA slightly after the origin of MA, with four branches directed to the posterior wing margin; middle part of MP sclerotised. Cubital vein forks into CuA and CuP near the base of wing; both veins simple, CuA–CuP area with a few straight crossveins. A1 and A3 simple, A2 with fork.

Hind wing ( Fig. 3D ). Membranous, 16.7 mm long. Anterior margin of wing straight. Sc ending in RA near the apex of wing. Subcostal area narrower than RA–RS area. RA/RS fork slightly before the basal seventh of wing length; R fused with M for a short distance; RS+MA pectinate, with six branches. MP diverges from RS+MA slightly after the origin of RS, with long fork, middle part of MP strongly sclerotised. Cubital vein forks into CuA and CuP slightly before the origin of R. CuA–CuP area without crossveins. Anal veins simple.

Legs ( Fig. 4C, D ). Femora and tibiae of all legs with dense microsetae (clearly tomentose), spines and long setae absent but apical part of the tibia ventrally contains two relatively short apical spines. Fore leg with enlarged coxa; femur stout, 2.3 mm long; tibia 2.4 mm long. Mid leg similar to fore leg; femur 2.4 mm long; tibia 2.7 mm long, tarsus 5-segmented, apical segment with long tarsal claws, length of claw 0.5 times 5th segment ( Fig. 4D ). Hind legs well preserved ( Fig. 4C ); coxa enlarged; trochanter elongated; femur stout, 3.4 mm long, 3.5 times as long as wide; tibia 3.6 mm long, 1.1 times longer than femur; tarsus 5-segmented, length of 1st–4th segments almost equal and each segment ventrally with a pair of euplantulae; 5th segment longest, with large unpaired euplantula and long tarsal claws, arolium absent.

Eggs ( Figs 2B , 4E, D ). Lengths 1.5–1.6 mm. Capsule elongate; in lateral view, the ventral side S-shaped while dorsal side almost straight; lateral sides with three low longitudinal ridges. Operculum broadly oval.

Composition. Family consists of a type genus only.

Stratigraphic range. The lowermost Cenomanian, mid-Cretaceous, ca. 98.79 ±0.62 Ma ( Cruickshank & Ko, 2003).

Figures

FIGURE 1. Aristovia daniili gen et sp. nov., photograph of holotype. A, Habitus, dorsal view. B, The same, ventral view. Scale bars = 5 mm.

FIGURE 2. Aristovia daniili gen et sp. nov., photograph of holotype. A, Head and pronotum, dorsal view. B, Eggs, ventral view. Photograph by D.E. Shcherbakov. Reproduced with author’s permission. Scale bars = 1 mm.

FIGURE 3. Aristovia daniili gen et sp. nov., sketch drawing of holotype. A, Body, dorsal view. B, The same, ventral view. C, Right forewing. D, Combined drawing of right and left hind wings. Scale bars: A, B = 5 mm; C, D = 3 mm.

FIGURE 4. Aristovia daniili gen et sp. nov., sketch drawing of holotype. A, Head and pronotum, dorsal view. B, Left lacinia, ventral view. C. Mid tibia and tarsus, lateral view. D, Hind leg, lateral view. E, Egg, dorsal view. F, The same, lateral view. Scale bars = 1 mm.