Platyxyela, Wang, Mei, Shih, Chungkun & Ren, Dong, 2012

Wang, Mei, Shih, Chungkun & Ren, Dong, 2012, Platyxyela gen. nov. (Hymenoptera, Xyelidae, Macroxyelinae) from the Middle Jurassic of China, Zootaxa 3456, pp. 82-88 : 84

Family Xyelidae Newman, 1834

Subfamily Macroxyelinae Ashmead, 1898 Genus Platyxyela gen. nov.

Type species: Platyxyela unica sp. nov.

Diagnosis: Pterostigma sclerotized completely, the antennomere 3 shorter than the other flagellomeres combined, costal area obviously broadest just before the separating point of Rs, Sc2 meeting R only a short distance before origin of Rs, Sc2 nearly equal to the first segment of Rs, and the latter shorter than basal segment of M, hind wing with basal section of Rs very short, and 1r-m intersecting Rs a little beyond origin of Rs, cell 1Cu narrow and longer than cell R, ovipositor with sheath extending far beyond metasomal apex, and relatively wide, nearly as wide as the length of mid metasomal terga.

Etymology: The generic name is a combination of Greek prefix “ platy -” referring to the broad costal area, and “ xyela ”, the name of one of the genera in Xyelidae . The gender is feminine.

Species included: P. unica sp. nov.

Remarks:

This new genus Platyxyela gen. nov., with complex wing venation, very long antennomere 3 (nearly as long as remaining flagellomeres), and two branches of Rs, is clearly a member of Xyelidae . In Macroxyelinae, pterostigma sclerotized either throughout, or except posterocentrally, or only basally, or along the margins. In the tribe Gigantoxyelini, pterostigma sclerotized throughout. The pterostigma of this new genus is sclerotized throughout, with no individual veins discernible, and moderately short 1m-cu indicate that the new genus belongs to the subfamily Macroxyelinae and the tribe Gigantoxyelini. There are four genera ( Gigantoxyela , Chaetoxyela, Shartexyela, Heteroxyela ) belonging to the tribe Gigantoxyelini up to now ( Rasnitsyn 1969; Zhang & Zhang 2000).

This new genus differs from Gigantoxyela in the latter with very short flagellum (antennomere 3 three times as long as the rest flagella combined), forewings with 4-branched Sc; differs from Chaetoxyela in Sc2 entering R just at origin of Rs; differs from Shartexyela in the latter with 3-branched Sc, first free section of Rs slightly longer than basal section of M. Platyxyela gen. nov. is very similar to Heteroxyela in Sc entering R before origin of Rs, but can be differentiated from latter by the following characters: 1) the first segment of Rs shorter than the first segment of M; 2) Sc2 nearly equal to the first segment of Rs; and 3) terminal part of flagellum 1.15 times of antennomere 3 in length.