Studies on the Late Mesozoic snake-flies of China (Raphidioptera: Baissopteridae, Mesoraphidiidae, Alloraphidiidae)

Abstract

well preserved fossil snake-fly specimens were collected recently by the author from the Late Jurassic Yi-clan Formation of Beipiao City, Liaoning Province. They belong to Bais- sopteridae, Mesoraphidiidae and Alloraphidiidae and include 10 genera and 14 species. Of them 4 genera and 7 species are new to science. All the type specimens are preserved in the Geological Museum of China, Beijing. Baissoptera euneura sp. nov. (Plate I: 1 ) Fig. 1) Holotype No. LB95101, Beipiao City, Liaoning Province ; Late Jurassic Yi-clan For- mation. Characters of body are shown in Fig. 1. The new species similar to B. martinsoni, but differs from latter in the number and form of Rs, longer branches of 2A, the forking form of MP in hindwing. The new species can also be distinguished from the B. grandis by all the branch of Rs bifurcating, R_1 with 2 or 3 terminal branches, 1A with 3 terminal branches, and longer branches of 2A. Rudiraphidia gen nov. Type species: Baissoptera liaoningensis Ren, 1994. Diagnosis. Head nearly elliptical, longer than prothorax. Pronotum square,longer than meso-and metathorax combined. Sc terminating beyond mid-wing. Pterostigma elogate., with a crossvein. A crossvein between Sc and R_1 locates basad of the separating point of Rs from R. CuA joins M distad of the separation of M from R. MA in the hindwing originates from R. The short vein (be) from base of MP to CuA is very long and curved. Fore- and hind wings with more cells in Rs and M areas. Comparison. The new genus differs from the Baissoptera in square pronotum not only shorter than head but also shorter than Meso-and metathorax combined, a crossvein be- tween Sc and R, basad of separation of Rs from R. Distribution. Liaoning, Late Jurassic. Phiradia myrioneura sp. nov. (Plate II: 2, Fig. 5) Holotype No. LB95110. Beipiao City, Liaoning Province; Late Jurassic Yixian Forma- tion. Characters of body are shown in Fig. 5. This new species can easily be separated from P. pterostigmalis (Martynova) by having more closed cells between Rs and R_1, MA with more terminal branches, 2 crossveins be- tween MA and MP in the hindwing. Mioraphidia gen. nov. Type species: Mesoraphidia furcivenata Ren, 1995. Diagnosis. Pterostigma elogate, without crossvein. MA in the fore wing originates from the point of forking of MP. Rs with 3 terminal branches, MA with 2 branches. The forking features of MP in forewing is without the usual fork as in Mesoraphidta and Phira- dia, 4 crossveins present between anterior and posterior main branches of MP. Crossveins absent among posterior main branches of MP. Comparison. The new genus can be distinguished from Mesoraphidia and Phiradia by the special forking form of MP in the forewing, which only similar to the features of the hlndwings of Mesoraphidia. Distribution. Beijing, Early Cretaceous. Mesoraphidia heteroneura sp. nov. (Plate I: 3, Fig. 6) Holotype No. LB95111. Beipiao City, Liaoning Province; Late Jurassic Yi-clan Forma- tion. Characters of body are shown in Fig. 6. The new species can be easily separated from the all known species of this genus by sin- gle R_1, Rs with 3 terminal branches, forking form of MA, less branches of MP. Mesoraphidia sinica sp. nov. (Plate I: 5, Fig. 7) Holotype No. LB95112. Beipiao City, Liaoning Province; Late Jurassic Yixian Forma- tion. Characters of body are shown in Fig. 7. This new species differs from all known species of the genus in hasal piece of MA obviously longer than the hasal part of Rs, 3 closed cells between R, and Rs, only 1 crossvein among branches of MP in hindwing. Mesoraphidia amoena sp. nov. (Plate I: 2, Fig. 8) Holotype No. LB95113, LB95114 (part and countpart ). Beipiao City, Liaoning Province; Late Jurassic Yixian Formation. Characters of body are shown in Fig. 8. The new species is related to M. sinica sp. nov., but differs in 2 close cells between R, and Rs, first hasal part of MA not long, posterior branch of MA in the hindwing forking earlier. Alloraphidia anomala sp. nov. (Plate 11: 4, Fig. 9) Holotype No. LB95117. Beipiao City, Liaoning Province ; Late Jurassic Yi-cl