Utrillabracon electropteron Alvarez-Parra & Engel, 2022

Alvarez-Parra, Sergio, Penalver, Enrique, Delclos, Xavier & Engel, Michael S., 2022, A braconid wasp (Hymenoptera, Braconidae) from the Lower Cretaceous amber of San Just, eastern Iberian Peninsula, ZooKeys 1103, pp. 65-78 : 65

Utrillabracon electropteron Alvarez-Parra & Engel sp. nov.

Fig. 2

Material.

Holotype, MAP-7819 (SJE2012 49-04), sex unknown, from San Just amber. The holotype is largely preserved as the forewings and hind wings. Some parts of the head, an antenna, and a leg are next to the wings. Undetermined cuticular fragments are visible near the wings. Deposited in the Museo Aragones de Paleontologia ( Fundación Conjunto Paleontológico de Teruel-Dinópolis) in Teruel, Spain. Syninclusions include three other hymenopterans (probable serphitid, platygastrid, and stigmaphronid wasps). The holotype is prepared isolated in an epoxy prism of 20 × 15 mm.

Locality and horizon.

San Just amber-bearing outcrop, Utrillas, Teruel, Spain; Maestrazgo Basin, Escucha Formation, upper Albian ( Peñalver et al. 2007).

Diagnosis.

As for the genus (vide supra).

Description.

Head deformed and incomplete as preserved (Fig. 2A, B ); antenna partially preserved with 11 flagellomeres covered by setae, multiporous plate sensilla not visible; only distal two maxillary palpomeres preserved, covered by fine setae. Forewings and venation rather complete (Fig. 2C ), forewing base not preserved, more than 1.31 mm long and 0.53 mm in its maximum width, margin bearing setae; C + Sc + R fused anterobasally, extending along wing margin to pterostigma; pterostigma 4 × longer than wide (0.33 mm vs 0.08 mm); elongate marginal cell, 3 × longer than wide (0.57 mm vs 0.19 mm), reaching wing apex; 1Rs relatively long and curved; Rs + M slightly sinuous; first submarginal cell 2 × longer than wide (0.31 mm vs 0.15 mm), pentagonal; 2Rs slightly sinuous; r-rs oblique, arising medially from pterostigma, 0.08 mm long; 3Rs extending nearly straight until wing margin, 0.55 mm long; r-rs several times longer than abscissa of M between 2Rs and m-cu; 1M curved, 2 × longer than 1Rs (0.14 mm vs 0.07 mm); 2M straight, 0.38 mm long; almost straight 3M, disappearing before wing margin; rs-m nebulous, 0.13 mm long; elongate, pentagonal second submarginal cell, 3 × longer than wide (0.38 mm vs 0.13 mm); trapezoidal third submarginal cell, 0.31 mm long; first discal cell almost 2 × longer than wide (0.21 mm vs 0.12 mm); m-cu distinctly postfurcal (absence of a vein 2Rs + M), 0.12 mm long; lacking 2m-cu; elongate second discal cell, 0.63 mm long; cu-a (nervulus) slightly postfurcal (therefore presence of an exceptionally short 1Cua), 0.06 mm long, perpendicular to 1Cu and A; 1Cu nearly straight, 0.14 mm long; 2Cu strongly curved basally separating 2Cua (0.05 mm long) and 2Cub, latter curved and directed towards wing margin (but without meeting margin); first subdiscal cell 2 × longer than wide (0.13 mm vs 0.07 mm); elongate and narrow second subdiscal cell; A tubular and nearly straight; 1a and 2a not visible. Hind wings and venation rather complete (Fig. 2D ), hind wing base not preserved, more than 0.94 mm long and 0.23 mm at its maximum width, margin bearing setae; Sc + R fused anterobasally; R1 distally widened with several hamuli beyond its apex; Sc + R not aligned with Rs; 1M short, 0.05 long; rs-m oblique, 0.07 mm long; Rs and M ending as nebulous veins before margin; 1Cu + cu-a inclivitous, 0.03 mm long; short 2Cu, not contacting wing margin. Two fragments of legs visible: a partial femur and a tarsus; four distal tarsomeres preserved covered by fine setae (Fig. 2E, F ), tarsomere III 0.06 mm long, tarsomere IV 0.04 mm long, tarsomere V 0.08 mm long; pretarsus with paired claws, preapical tooth absent, arolium wide.

Etymology.

The specific epithet is a combination of the Greek ἤλεκτρον ( élektron), meaning, “amber”, and πτηνόν ( ptéron), meaning, "winged creature", and referring to the fact that the holotype is mainly preserved by the wings in amber.

Figures

Figure 2. Utrillabracon electropteron Alvarez-Parra & Engel, gen. et sp. nov. (Braconidae, † Protorhyssalinae) from the upper Albian amber-bearing outcrop of San Just, specimen MAP- 7819 (SJE 2012 49 - 04). A, B photograph and drawing of preserved remains, both to the same scale C forewing venation D hind wing venation E, F photograph and drawing of tarsus and pretarsus, both to the same scale. Abbreviation: pt = pterostigma. Scale bars: 0.5 mm (A, B); 0.2 mm (C, D); 0.1 mm (E, F).