Palaeochiridium insolitum gen. et sp. nov.

Figs 1–8

Type material. Holotype ♂ (PIN 5608 /335), paratype ♂ (PIN 5608 /336a), Burmese amber.

Description of inclusions. The cut pieces of amber with the type material have the following characteristics: the holotype (PIN 5608/335) has the shape of a prism with dimensions of 2.33 × 2.01 × 1.08 mm; the paratype (PIN 5608/336a) has an irregular prism with dimensions of 3.83 × 2.28 × 0.79 mm. Both pseudoscorpions are partially covered in milky matter.The holotype has a partially deformed carapace. In the paratype, the carapace is significantly deformed, and the pedipalps are also significantly deformed due to partial fragmentation. Due to severe deformation and damage to the paratype, all measurements were performed on the holotype. In both studied specimens, coxa IV is raised by about 55–60º relative to the other coxae and the longitudinal axis of the body, thereby distorting their proportions in the ventral view; however, we do not know whether this is a natural state or a change caused by fossilization. To measure the coxa IV we imaged the inclusions at the appropriate angle, as shown in Judson (2007a: fig. 12). In the form of coxa IV, the new genus and species correspond to the males of Pseudochiridiidae.

Geographic and stratigraphic ranges. Hukawng Valley southwest of Maingkhwan in Kachin State (26º20’N, 96º36’E), Myanmar; lowermost Cenomanian (ca. 99 Ma), Late Cretaceous.

Etymology. The new species was named from the Latin adjective neuter insolitum, which means unusual.

Diagnosis. Same as the genus.

Description. Adults (♂, ♀ unknown). Integument pigmented, carapace, abdomen, and legs amber-yellow color; chelicerae dark yellow; pedipalps pale brown to dark brown, with a light milky coating due to fossilization (Figs 2–5, 6A). Granules of dorsal surfaces large and irregular in form. Setae of dorsal surfaces large and strongly clavate, with jagged tops.

Carapace (Figs 2A, 5A, 7A, B) trapezoidal, with two weakly developed furrows: anterior 0.29–0.32 and posterior 0.72–0.77 mm the length of carapace from anterior margin; with well-developed cucullus; eyespots not visible; prozone with particularly large granules posterolaterally; setal formula of holotype 18: 4: 9 (31), paratype 19: 3: 5 (ca. 27, assuming that some of setae are missing). Posterior margin of carapace and tergites rounded (Figs 2A, 5A, 7A, B). Tergites triangular in lateral view, with setae located along their posterior margin (Figs 3A, 6A).

Pedipalpal coxae with strong granulation (Figs 2B, 5B); coxae of legs I–IV with large, nearly smooth (microgranulate) areas that lack macrogranules, coxa IV triangular with a long posterior extension; chaetotaxy of leg coxae I–III not visible, coxa IV with 42–46 very short setae.

Tergites weakly divided (except at least XI); rounded or very weak chevroned in dorsal view and triangular in lateral view; setae of holotype 5: 8: 8: 8: 8: 8:7: 2: 9: 9: 7, paratype 6?: 5?: 5?: 7?: 8?: 10: 9: 13: 11: 10: 9 (setae of tergites I–V are partially visible). Аnal plate subventral surrounded by tergite and sternite XI.

Setae of anterior genital sternite not visible; posterior sternite with a row of 6–8 smaller setae. Genitalia not visible. Setae of sternites III–XII not visible.

Chelicera (Figs 6B, 7C) with 4 simple setae on hand, b absent, ls more than twice as longer es; movable finger smooth and without teeth; galea long, twice as short as movable finger, forked at distal end; serrula exterior with at least 12–13 blades; rallum of two blades, in the distal part with small tooth in middle.

Pedipalp (Figs 2–5, 6C, D, 7A, B, 8) macrogranulated, with large clavate these setae, with jagged tops (except for some slightly expanded or setiform setae on chelal hand and fingers); granulation of chela extending onto fixed finger, forming slight dorsal elevation in lateral view; trochanter and femur noticeably widened (2–3 times wider than patella); palps non typical, more elongate than in other species of the family; venom apparatus present on both chelal fingers. Trichobothrium isb distal of esb; ist over it; position of t variable—on holotype distal to st and on paratype above st. Fixed finger with 21–22 rounded blunt teeth; movable finger with 16–18 teeth, most of teeth cuspidate and inclined backwards with 2–6 rounded blunt teeth at base of finger.

Legs I–IV with mobile joint between femur and patella; setae of legs clavate, with jagged tops proximally (Figs 3B, 7D) and simple and long in in distal part of tarsi; arolia of legs simple and slightly shorter than claws.

Type locality. Hukawng Valley southwest of Maingkhwan in Kachin State (26º20’N, 96º36’E), Myanmar.

Measurements and ratios of holotype. Body 0.601 × 0.433 (0.844 × 0.552 paratype). Carapace 0.292 × 0.130 (2.25). Palp femur 0.153 × 0.122 (1.25), patella 0.188 × 0.044 (4.27), chela + 0.388 × 0.061 (6.36), chela – 0.356 (5.83), hand + 0.212 (3.47), hand – 0.182 (2.98), movable finger ca. 0.214 (ca. 1.0 × hand +, 1.17 × hand –). Leg II tarsus 0.128 × 0.020 (6.40). Leg IV coxa 0.102 × 0.054 (1.88), femur 0.077 × 0.055 (1.40), patella 0.094 × 0.058 (1.62), femoropatella 0.171 (3.02), tibia 0.133 × 0.041 (3.24), tarsus 0.177 × 0.028 (6.32).

Syninclusions. PIN 5608/336 (Figs 10, 11): numerous fecal pellets; Acari— 1 ex. Autogneta sp. (Oribatida: Autognetidae), 5 exx. Oppiidae (Oribatida), 1 ex. Oribatellidae (Oribatida), 1 ex.? Paratydeidae (Prostigmata), 2 ex. sp. indet. (? Mesostigmata), 1 ex. Prostigmata; Pseudoscorpiones — 1 ex. chelicera not Pseudochiridiidae, 1 ex. body without chelicerae, pedipalps and legs (presumably a nymph Palaeochiridium insolitum gen. et sp. nov.); Collembola —2 exx. Sminthuridae, 2 exx. sp. indet.; Blattodea— 1 ex. nymph; Coleoptera — 1 ex. imago Elateridae, 2 exx. imago Histeroidea, 3 exx. larvae of sp. indet.; Diptera — 1 ex. imago Ceratopogonidae, 1 ex. imago? Ceratopogonidae.