Zigrasimecia hoelldobleri

Distribution
This taxon was described from.

Nomenclature

 * †. †Zigrasimecia hoelldobleri Cao, Boudinot & Gao, 2020: 164, figs. 1-3 (w.) MYANMAR (Burmese amber).

Worker
Measurements (in millimeters) for holotype (No. CNU-HYM-MA2019053) and paratype (No. CNU-HYM-MA2019054, in brackets [ ]) specimens: Body length 3.53 [2.6]; head length (from vertex to clypeal margin) 0.8 [0.55], width (excluding eyes) 0.9 [0.5]; eyes diameter 0.2 [0.14]; total length of antenna 1.87 [1.11], scape 0.40 [0.12], pedicel 0.15 [0.07], flagellomeres I - X 0.17, 0.15, 0.12, 0.12, 0.12, 0.10, 0.10, 0.10, 0.10, 0.20 [0.12, 0.09, 0.09, 0.09, 0.08, 0.08, 0.07, 0.08, 0.08, 0.15], respectively; maxillary palp: 0.16, 0.12, 0.07, 0.04, 0.03, 0.05, respectively; labral palpomeres I - V: 0.04, 0.04, 0.04, 0.05, 0.07, respectively; mesosomal length 1.25 [0.57], maximum height [0.35]. Legs: forefemur 0.64, mesofemur 0.61, metafemur 0.73; protibia 0.52 in length; mid tibia 0.51 in length; hind tibia 0.62 in length. Petiole length [0.3], height (including subpetiolar process) ~ 0.4; [0.34]. Gastral length (excluding sting): gaster comprising segments III - VII of seven segments exposed of holotype: 0.6, 0.34, 0.18, 0.18, 0.16; total length [1.2] of paratype, sting [0.04].

Holotype No. CNU-HYM-MA2019053; Paratype, No. CNU-HYM-MA2019054, characters of paratype differing from holotype are described in brackets. Whole body covered with long, erect setae; many of the setae clavate [pointed, setae sharp at apex]; setae denser on legs, shorter and fewer on antennal flagellum.

Head: broad [In lateral view, head triangular; frons and lower face forming a plane]. Eyes bulging. Ocelli absent. Antenna with 12 antennomeres. Scape, pedicel as well as flagellomeres I - III covered with a few erect setae on ventral surface, which is shortening in each antennomere. Frontal carinae present between antennae, extending posterolaterally from posterior clypeal margin to anteromedian eye margin, carinae forming posterior margin of short, shallow scrobe. Clypeus curved across its length; lateralmost portions of clypeus, dorsal to mandibular insertion, expanded as disc-shaped lobes; anterior clypeal margin slightly emarginate medially; anterior clypeal margin with at least 48 [34] peg-shaped denticles arranged in a single row. Labrum large, filling most of oral area; distalmost margin covered with a row of short, crooked setae; distal margin with median slit-like cleft; at least 30 [54] suberect spiniform setae present across labral disc; these setae somewhat cone-shaped, with the proximalmost row relatively shorter and thinner. Mandibles with three rows of stiff and spicule-like setae along basal margin; these setae of three different level lengths, the outermost row shortest and the innermost row longest; apex of subapical tooth aligning with apical tooth; both teeth of masticatory margin short, being subequal in length to clypeal traction; a single long seta present on outer mandibular surface. Maxillary palp 6-merous, with erect setae.

Mesosoma: very compact, with dorsal margin evenly convex in lateral view; dorsal lines between each sclerite completely effaced. Mesothorax narrow; metathorax and propodeum in profile with dorsum distinctly rounded [paratype: posterior flange of propodeum forms an angle that is slightly smaller than 90°]; propodeal spiracle slit-shaped. Tibial spur formula 2s, 2(1s,1p); protibia with single spiniform seta posterior to calcar; pectinate metatibial spur large relative to simple spur, which is also subtended by a spiniform seta. Probasitarsus covered with patch of dense setae on ventral surface. Pretarsal claws dentate. Apicomedian lobate setae (plantar lobes) on ventral apex of tarsomeres I - IV absent.

Abdomen with seven exposed segments. Petiolar node squamiform (compressed anteroposteriorly); vertex of petiolar node medially emarginate [for paratype: ventral surface of petiole even, subpetiolar process presence uncertain]. Helcium short. Gaster five segments. Gastral tergum I evenly convex to posterior margin; posterior margins of tergum and sternum I not cinched, that is, not having posteriorly-directed surfaces. Gastral segment II without defined cinctus [for paratype, the second gastral segment distinctly larger; sternite of gastral segment V larger than tergite, connected with tergite closely, gradually narrowing to apex, slightly upcurved apically]. Sting short but stout, largely internalized and only an element of sting exposed.

Type Material
Holotype: No. CNU-HYM-MA2019053, worker; Paratype: No. CNU-HYM-MA2019054, worker. Kachin (Hukawng Valley) of northern Myanmar. The lowermost Cenomanian (near Albian boundary).

Burmese amber, Noije Bum hill, some 18 km southwest of Tanai Village in the Hukawng Valley, of northern Myanmar. Depository: Key Lab of Insect Evolution and Environmental Changes, College of Life Sciences, Capital Normal University (CNU), Beijing, China.

Etymology
The specific name is in honor of myrmecologist Dr. Bert Hölldobler, for his outstanding contributions on studying evolution and social organization in ants.