Formicoidea Latreille, 1809, 1866

Boudinot, Brendon E., Perrichot, Vincent & Chaul, Julio C. M., 2020, † Camelosphecia gen. nov., lost ant-wasp intermediates from the mid-Cretaceous (Hymenoptera, Formicoidea), ZooKeys 1005, pp. 21-55 : 21

Formicoidea Latreille, 1809

Definition.

Detailed study of the † Camelomecia clade has redefined the Formicoidea and refined our understanding of the definition and evolutionary patterning of the total and crown Formicidae ( Boudinot et al. 2020a). Formicoids, we now know, are a clade of Formicapoidina (sister to Apoidea : Johnson et al. 2013; Branstetter et al. 2017; Peters et al. 2017) defined by positive (i.e., non- “absence” character) morphological synapomorphies most of which form an innovation suite for cursorial or surface-based predation, including: (1) prognathy and elongation of the postgenal bridge (Figs 13A , 14B ); (2) enlargement of the dorsal (cranial) mandibular condyle (Fig. 13A ); (3) rotation of the antennal toruli laterad in females (Fig. 13A, B ); (4) elongation of the procoxae (Figs 14A , 15A ); (5) partial to complete enclosure of the proximal protrochanteral articulations within the distal procoxal foramina (Figs 14E , 15A , 16E ); (6) internalization of the proximal meso- and metacoxal articulations within the mesosoma (Figs 14B , 15A , 16 ); (7) petiolation of the first metasomal segment (Figs 14A , 15A , 16A, D, E ); (8) gain of the anteroventral process of the petiolar sternum (Fig. 16A ); (9) buttressing of the metasomal waist through gain of the prora (an anteroventral process of the second metasomal sternum) (Figs 15A , 16A, D ); plus (10) an angled juncture between the first free abscissae of Rs and M in the fore wing (Figs 15A , 16A, D ). The † Camelomecia clade, in contrast to the total clade of the Formicidae , probably lack the metapleural gland and apterous workers altogether, while also being defined by a combination of derived and plesiomorphic features (see, e.g., the key below). Based on direct examination of the unique specimen (holotype) of † Camelomecia janovitzi (BEB at the AMNH, 2017), presence of this gland is uncertain and requires further scrutiny.

Figures

Figure 13. Holotype of † Camelosphecia fossor sp. nov. A lateral view of right side of head B full face view of head, right margin blurred on this view due to a folding of the facet. Box on bottom right evidencing scape under fluorescent microscopy C detail of clypeus, mandibles and labrum under fluorescent microscopy D posterodorsal view of anterior section of funiculus (pedicel plus flagellum), evincing pedicel and antennomeres III and IV. Abbreviations: a 3 - 5, antennomeres III-V; abdsw, abductor swelling; bs, bubble stream; ce, compound eye; cl, clypeus; clb, clypeal lobe; clt, clypeal teeth; crcond, cranial condyle; md, mandible; mm, masticatory margins; lbs, labral chaetae; mdcond, mandible condyle; mxp, maxillary palps; oc, ocelli; occ, occipital carina; pd, pedicel; prvmdpr, posteroventral mandible process; sc, scape. Scale bars: 0.2 mm (A, B); 0.1 mm (C); 0.02 mm (D).

Figure 14. Holotype of † Camelosphecia fossor sp. nov. A profile of left side of body B profile of right side of body C dorsal view of mesosoma D delimited area of C under fluorescent light E details of the legs, especially the forelegs. Abbreviations: A 2 - A 3; abdominal segments 2 and 3; aprntr, anterior pronotal rim; ca, calcar; mscx, mesocoxa; msfm, mesofemur; msnt, mesonotum; mspl, mesopleural region of mesopectus; mssctm, mesoscutum; mssctl, mesoscutellum; mtcx, metacoxa; mtfm, metafemur; mtpl, metapleural region of metapectus; plant, plantulae; pr, prora; prcx, procoxa; pretc, pretarsal claws; prfm, profemur; prnt, pronotum; prop, propodeum; proppj, propodeal projection; prots, protarsomeres I and II chaetae; prtbss, distal protibia stout chaeta; psctc, parascutal carina; sp, propodeal spiracle; strg, strigil. Scale bars: 0.2 mm.

Figure 15. A-C † Camelosphecia spp. females examined by images. Specimens in A (BALBuTJ _ 36) and C (BALBuTJ _ 40) are likely conspecifics to † C. fossor. Specimen in B (BALBuTJ _ 38) is probably another species in the genus, not described in here (images by Phil Barden, used with permission) D, E are generalized schemes of † Camelosphecia habitus and forewing, respectively, as interpreted from all specimens examined. Metathoracic sclerites in A-C are indicated with green dots. In D, pedicel and flagellomeres are omitted for simplification. Abbreviations as in Figure 14, except for prstA 4, presternite of A 4; prpl, propleuron; tbsp, tibial spurs; stA 4, sternite of A 4; stng, sting. Wing venation abbreviations: C, costal vein; Sc, subcostal vein; R, radial vein; Rs, radial sector vein; M, medial vein; Cu, cubital vein, A, anal vein; +, indicates composite vein; f , indicates free abscissa index; 2 r-rs, second radiosectoral crossvein; 2 rs-m, second sectoriomedial crossvein; 1 m-cu, first mediocubital crossvein; 1 cu-a, first cubitoanal crossvein; R (bc), radial or " basal " cell; 1 + 2 R (smc 1), undifferentiated first and second distal radial cells or " first submarginal cell "; 3 R (mc 1), third distal radial or " first marginal " cell; 1 Rs (smc 2), first sectorial or " second submarginal " cell; 1 M (dc 1), first medial or " discal " cell; 1 Cu (sbc), first cubital or " subbasal " cell; 2 Cu (sdc 1), second cubital or " first subdiscal " cell.

Figure 16. † Camelosphecia venator sp. nov. holotype (NIGP 163574) A, D right and left profile view of body, respectively B, C right and left profile view of head, respectively E left mesosoma zooming. Abbreviations: ce, compound eye; cl, clypeus; md, mandible; mm, masticatory margins; oc, ocelli; occ, occipital carina; A 2 - A 3; abdominal segments 2 and 3; mscx, mesocoxa; mspl, mesopleural area of mesopectus; mssctm, mesoscutum; mtcx, metacoxa; mtpl, metapleural area of mesopectus; oms, oblique mesopleural sulcus; pr, prora; prcx, procoxa; prnt, pronotum; prop, propodeum. Note that indication of clypeus in C is exactly at its margin as seen in profile, which is concave, and should not be confused with convex right compound eye margin, also indicated. Clypeal concave shape is better evidenced in figure B. Also in C, mm indicated is from the right mandible, while mandible indicated is that of the left side. Scale bars: 1 mm (A, D); 0.2 mm (B, C, E).