Sauronaradus meganae, Cumming & Mlynarek, 2024

Cumming, Royce T. & Mlynarek, Julia J., 2024, An additional ✝ Archearadinae flat-bug species from Cretaceous Burmese Amber (Hemiptera, Aradidae), ZooKeys 1219, pp. 123-133 : 123-133

Sauronaradus meganae sp. nov.

Figs 1 , 2

Type material.

Holotype: specimen number IMQC -AMB-ara 0001 ; Hukawng Valley , Myanmar, accession c. 2010; male; specimen deposited within the Montreal Insectarium, Montreal, Quebec, Canada ( IMQC).

Taphonomy.

Ovular piece of clear amber (~ 15.5 × 10.9 mm), with minimal debris obscuring the holotype (Fig. 2 D ). The holotype is wholly intact and appears to have little warping. Due to the dark coloration the wings are difficult to discern as they are tucked closely to the abdomen surface. One syninclusion is present, a slightly damaged Cretopiesma suukyiae Grimaldi & Engle, 2008 .

Type locality and horizon.

Latest Albian to lowermost Cenomanian (mid-Cretaceous), Hukawng Valley, northern Myanmar.

Etymology.

Patronym, named to honor Megan Solan, environmental toxicologist and entomologist. The first author wishes to thank Megan for her years of friendship and passion for entomology. Her enthusiasm for research is infectious and a positive driving force in the sciences.

Diagnosis.

Currently the genus is monotypic. See the above diagnosis of the genus for differentiation of this species from other aradids.

Description

(All measurements are in mm and based on the holotype). Macropterous male; large, 5.05 long, 1.88 wide; body flattened (Figs 1 , 2 ).

Head 1.16 long, 0.89 wide (across the compound eyes); dorsally and ventrally rough textured. Compound eyes strongly protruding (Fig. 2 A ). Ocelli absent. Clypeus long, protruding, and boxy, with two clearly defined widths, broad for the posterior half (loral lobe), then half as wide on the apical half (maxillary lobe; Fig. 2 B ). Dorsally there is a prominent anteclypeus on the posterior half (Fig. 2 A ). Clypeus loral lobe with two prominent apically pointing tubercles on each side; clypeus maxillary lobe with nodes on the dorsal and lateral surfaces (Fig. 2 B ). Ventral surface of head with nodes similar to the dorsal surface nodes, and a narrow median depression of gula (Fig. 2 E ). Bucculae not prominent. Open rostral atrium arising between the compound eyes, not at the apex of clypeus. Four, prominent, conical tubercles are present on the dorsal surface of the head. One pair are anteorbital tubercles present near the base of the compound eyes, and the second pair are situated evenly between the anteorbital tubercles (Fig. 2 A ). These four tubercles are of similar size and shapes. Head lacking prominent postocular lobes, instead immediately behind the compound eyes is the notably constricted postocciput, which is slightly narrower than the anterior of the pronotum.

Antenna exceptionally long and thin with antennomeres II, III, and IV with lengths c. 20–22 × their widths. Antenna with four antennomeres; basal antennomere (scape) the shortest, antennomere lengths: I: 0.27, II: 0.62, III: 0.70, IV: 0.74; antennomeres II, III, and IV tubiform; antennomeres II and III with surface granulation, and antennomere IV densely marked with setae throughout the surface with the seta length slightly less than the antennomere width, with the seta strongly angled apically (Fig. 1 E ). Antenniferous lobe prominent with a granular surface; stout, not projecting apically beyond the antennal insertion. Antennal insertion one-third of the way between the compound eyes and the apex of the clypeus (Fig. 2 B ). Rostrum with four segments extending to the posterior margin on the procoxal cavity (~ 1.73 mm long; Fig. 2 E ).

Thorax pronotum (0.99 mm long, greatest width 1.44); roughly trapezoidal in shape (increasing in width caudally) but with somewhat undulating margins (approximate widths from the anterior to the posterior: 0.42 mm, 0.99 mm, 1.44 mm, 1.24 mm; Fig. 2 C ). Pronotum lateral margin armed on the anterior two-thirds with three prominent spiniform tubercles (anterior most 0.11 mm, middle 0.10 mm, posterior-most 0.15 mm long; Fig. 2 B ). The posterior third of the pronotum bulges out to a width of 1.44 mm, and this bulge is armed with several smaller tubercles (Fig. 2 B ). Pronotum surface punctate throughout, with two paramedial carinae on each side of the sagittal plane, the central pair of carinae extend the full length of the pronotum and diverge in a similar fashion to the pronotum width, while the exterior carinae are less pronounced and are more prominent on the posterior half (Fig. 2 C ). Carinae jagged in form, not uniform in intensity throughout the lengths, somewhat rising and falling in rough textures (Fig. 2 C ). Scutellum long and prominent, 1.24 mm wide, 1.16 mm long; dorsal surface with the anterior third slightly raised above the posterior two-thirds; surface flat but punctate throughout; apex broadly rounded. Prosternum; 0.49 mm long, surface punctate and marked with a moderate rostral groove which continues onto the mesosternum as a broader depression along the sagittal plane (Fig. 2 E ). Mesosternum maximum width 1.44 mm, length 0.51 mm; ventral surface punctate (Fig. 2 E ). Metasternum 0.51 mm long, 1.59 mm wide.

Legs long and thin, all with slightly granular surfaces. Profemora 0.90 mm long, thinner on the proximal third. Leg lengths: protibiae 0.75 mm, mesofemora 0.92 mm, mesotibiae 0.60 mm, metafemora 1.16 mm, metatibiae 0.93 mm. Tibiae with sparse setae throughout, with longer and thicker setae on the distal ends (Fig. 2 F ). Tarsi with two tarsomeres; apical tarsomere is 1.5–2.0 times longer than the previous tarsomere; apical tarsomere thin proximally, widening notably for the proximal half, then a uniform broad width on the distal half (Fig. 2 F, G ). Apical tarsomere ventrally with few thin setae, previous tarsomere with thicker but sparse setae on the distal end (Fig. 2 F ). Tarsal claws long and simple; pulvilli approximately lemniscate, slightly shorter than tarsal claws (Fig. 2 F, G ).

Wings fully developed, but details are indiscernible due to taphonomy of the holotype.

Abdomen broad and flat, all surfaces punctate; length 2.41, greatest width 1.88 mm. Abdominal segment lengths: III = 0.57 mm, IV = 0.34 mm, V = 0.32 mm, VI = 0.37 mm, VII = 0.43 mm, VIII = 0.40 mm. Each abdominal segment has margins which gently undulate, with four or five humps, the posterior-most of which is on the posterior margin and larger than the others (Fig. 1 C, D ). Male terminalia broad and roughly bell shaped, surfaces rugose, a distinctly raised median ridge protrudes on the dorsal surface (Fig. 1 C, D ). Paratergite VIII rhomboid, angulated posteriorly, with the lateral margin slightly undulating (Fig. 1 C, D ).

Figures

Figure 1. Sauronaradus meganae gen. et sp. nov. holotype A dorsal habitus B ventral habitus C abdomen, dorsal D abdomen, ventral E right antenna, dorsal.

Figure 2. Sauronaradus meganae gen. et sp. nov. holotype A anterior lit to highlight the spines of the head, dorsal B head through thorax, dorsal C pronotum, lit to highlight carinae, dorsal D full amber piece with holotype inclusion and Cretopiesma suukyiae syninclusion to the lower right of Sauronaradus meganae gen. et sp. nov. E head through thorax, ventral F pro- and meso- legs, mesotibia and tarsus visible, dorsal G right metatibia, dorsal.