山东莱阳盆地早白垩世龙草蛉新属(昆虫纲:脉翅目)

DRAKOCHRYSA, AN EARLY CRETACEOUS NEW GENUS OF CHRYSOPIDAE (INSECTA:NEUROPTERA) FROM LAIYANG BASIN,SHANDONG PROVINCE

本文记述山东莱阳盆地早白垩世莱阳组(K_1l^3)草蛉科的一个新属——龙草蛉属(Drakochrysa gen.nov.)。新属以其脉序特色而区别于相近的幻草蛉属(Nothochrysa),并修改了中草蛉属中一个种归入本新属。同时对草蛉科各个亚科的地史分布及新属的分类位置作了讨论。

The Laiyang basin is situated in the central part of the Jiaodong Peninsula in Shandong Province, where the late Mesozoic continental sediments are well developed and widespread, especially from the Beibozi village to Tuanwang village,in Laiyang County. There are abundant fossil insects and other fossils including fishes, conchostracans and plants. , The Mesozoic continental sediments in this basin were studied by Tan Xichou (1923) who first established the late sequence and discussed its geological age (Table 1). The fossil insects were studied and reported by Grabau A. W. (1923), Bing Ch. (1928), Hong Y.C. (1984). Up to the end of 1984 there were established a total of 10 genera and 12 species of fossil insects in the Laiyang Basin. From 1963 to 1986, while making a detailed study of the late Mesozoic stratigraphy in this basin the author and other workers were fortunate enough to be entrusted with the study of the fossil insects and other taxa. The abundant insects were discovered from 16 localities in the Laiyang Basin. Among them a new genus 'Drakochrysa'is described here withdiscussion of its taxonomic position. Table 1. Cretaceous (K) The new genus 'Drakochrysa' was collected from the greyish black, grey ish green thin-bedded shale (called 'paper shale') intercalated with the thin-bedded siltstone of the Third Member of the Laiyang Formation (K) lying west of Tuanwang, Laiyang County. The specimens are preserved in the Beijing Natural History Museum. I Systematic Description Order Neuroptera Linn6, 1758 Superfamily Hemerobioidea Latreille, 1802 Family Chrysopidae Hagen, 1866 Subfamily Nothochrysopinae Navds, 1910 Genus Drakochrysa gen. nov. Type speciest Drakochrysa sinica sp.nov.; West of Tuanwang, Laiyang County in Shandong Province; Third Member of Laiyang Formation (K). Remarks: Sc very long, curved; Subcostal area with 1 ?2 branches situated after the Rs base; MP, and MP2 zigzag between the intergradated and outergradated crossveins, forming the pseudomedian and pseudocubital parts; m-cu situated near the wing apex about 3/4 of the wing length; CuA forked very late and with four branches near the wing margin. Description: Head lacking; Mesothorax slightly broader than the metathorax; Sctl3 triangular; sctl3 heart-shaped; Forewing larger and broader than the hindwing. Forewing venation: Wing broader; Wing margin arcuate; C stretched conspicuously obliquely upward, then curved downward; Costal area with more than 12 branches, arranged irregularly; Sc running upward obliquely, ended near C, then entering the costal margin; Subcostal area with an oblique crossveins; R base running near Sc, straight, oblique and fused with M; Rs base connected with MA, then separated from it; Rs forked into 8 branches Rs1-Rs8; Wing surface marked with two groups of gradated crossveins (intergradated and outergradated), these crossveins zigzag in the wing surface; M base combined with R, then forked into MA and MP; MA connected with R, then separated from it, and again connected with Rs, then saparated from it again; MP base slightly curved and forked into MP[ and MP2, zigzag twice and/ or thrice then reaching the wing margin; all branches with marginal bifurcations; pseudomedian somewhat longer than the pseudocubitus; MP area with two median crossveins (Im-m, 2m-m) and with two median cells: intermedian cell (or m,2m) and median cell ( 2m ), these two median crossveins belonging to the intergradated and outergradated crossveins; CuA very long and forked into 4 branches near the wing margin; CuP stem short, 3 branches; CuA-CuP area with a crossvein; b cell (basic cell) small; Anal area with 4 branches; Pt curved and long. Hindwing venation; It resembles to the forewing, but differs from the later in having a narrower subcostal area. Forewing 10.5mm long, 4 mm wide; Hindwing 9.5 mm long, 3.7 mm wide. II Systematic Discussion The Chrysopidae Hagen, 1866 may be subdivided into four subfamilies (Canad M.et al., 1984); Mesochrysopinae (J3), Nothochrysopinae (J3-T), Chrysopinae (T R) and Apochrysopinae (