Phylloleon elegans Lu, Wang & Liu, 2019

Phylloleon elegans Lu, Wang & Liu sp. nov.

( Figs 3–5 View Figure 3 View Figure 4 View Figure 5 )

Diagnosis. Generally same as for the genus. In addition, forewing more acutely produced distad, and fore- and hind wings almost equal in width.

Material. Holotype, NIGP 168257 , amber piece preserving a partly preserved adult female of Phylloleon elegans , together with a mayfly and some hymenopterans and dipterans. It is polished in the form of a flattened rhombus cabochon, with length × width about 58.0 × 40.0 mm, height about 1.0 mm. Paratype, NIGP 168258 , amber piece preserving a poorly preserved adult of Phylloleon elegans , and a psychopsid larva. It is polished in the form of a flattened subellipse cabochon, with length- × width about 40.3 mm × 30.0 mm, height about 8.60 mm .

Etymology. The specific epithet elegans refers to elegant appearance of the new species. An adjective in the neuter gender.

Description. Body length 9.85 mm; head 0.56 mm long and 1.17 mm wide; distance between compound eyes 0.32 mm; antenna length 3.86 mm; prothorax 0.55 mm long and 0.54 mm wide; mesothorax 1.41 mm long and 1.30 mm wide; metathorax 0.49 mm long and 0.67 mm wide; forewing 17.60–20.37 mm long and 5.02–5.35 mm wide; hind wing 16.76–18.17 mm long and 4.76–5.01 mm wide; abdomen 7.46 mm long and 1.72 mm wide.

Head orthognathous, much wider than long. Compound eyes large, semi-globular; diameter of eyes much shorter than distance between compound eyes. Antenna slightly dilated distad, nearly as long as length of head plus thorax.

Prothorax slightly widened posteriad, much longer but narrower than head; meso- and metathorax robust, metathorax slightly smaller than mesothorax. Wings elongated, transparent and immaculate.

Forewing leaf-like, with narrow wing base and acuminated apex. Costal space quite narrow proximally, strongly widened medially, and again slightly narrowed distad, with over 60 veinlets. ScA absent; ScP and RA fused together, slightly bending and running to wing margin posteriad wing apex; subcostal crossveins absent. Presectorial crossveins absent. Hypostigmal cell long. RP þ MA originating near wing base, and diverging into RP and MA distad midpoint of wing; 20 crossveins present in RA space; RP pectinately branched, with few crossveins among anterior branches; infra radial cell short. M proximally leaving a short oblique stem of MA that is fused with R near wing base; MA distally with three branches. MP1 long, almost straight for a long distance, distally slightly curved, with three branches. Base of MP2 (oblique vein) present proximad initial branching point of MP 2 þ CuA. CuA and CuP diverging near wing base; MP 2 þ CuA pectinately branched from proximal 1/4 into 18 straightly directing branches, posterior six branches of MP 2 þ CuA1 mostly bifurcated distad, while remaining branches of MP 2 þ CuA1 simple, CuA2 long and deeply branched; CuP long, pectinately branched into 10 simple branches; nine cua-cup crossveins present. A1 short and zig-zagged, forked from its midpoint into two simple branches, connected with CuP by two short crossveins; A 2 þ A3 short, pectinately branched into three branches.

Hind wing costal space broad and slightly widened distad, with 30 veinlets. ScP and RA distally fused together, running to wing margin slightly posteriad wing apex; subcostal crossveins absent. RP þ MA originating distad wing base, but slightly proximad midpoint of wing; eight crossveins present in RA space. Seven presectorial crossveins present. MP1 zig-zagged, MP2 nearly straight, both of them bifurcated distally. CuA long, with stem running parallel to posterior margin, and pectinately branched into 15 simple and short branches. CuP þ A1 very short, bifurcated; A2 simple, very weak; A3 absent.

Legs slender and long; tibiae and tarsi bearing several long spinous setae, these setae on tibia longer than those on tarsi, about 1/3 × length of tibia; tibial spurs slightly longer than tarsomere 1; numerous short setae present along tibiae and tarsi; protarsus nearly as long as protibia, meso- and metatarsus about half length of meso- and metatibia, tarsomere 1 and tarsomere 5 nearly equal in length, but much longer than the other tarsomeres; paired simple pretarsal claws present, slender and distally curved, opposable on last tarsomere; arolium absent.

Abdomen slenderly elongate, about 0.7 times as long as body length, with anterior three segments slightly narrower than remaining segments. Female genitalia preserved; segment 8 much shorter than segment 7, strongly narrowed ventral in lateral view, but with ventral sclerites not clearly visible; tergum 9 about half length of tergum 8, slightly tapering ventrad in lateral view; gonocoxites 9 ovoid, bearing long setae along ventral margin; ectoprocts ovoid, slightly directed ventrad, with long setae; callus cerci not detected.