中国科学院南京地质古生物研究所机构知识库

报道产于北京西山门头沟区色树坟石炭一二叠系太原组的一块蜚蠊类前翅化石,可归入Phyloblatta,代表一新种Phyloblatta beijingensis sp.nov.,以狭小的爪区别于该属其他已知种类。Phyloblatta蜚蠊类在我国山西省下二叠统山西组曾发现多种类型。对北京地区以前报道的昆虫化石所属时代和地层均进行厘定,如土城子组、大灰厂组、夏庄组的昆虫化石。

Here we report a new species belonging to the extinct genus Phyloblatta,Phyloblatta beijing- ensis sp.nov.,from the Carboniferous-Permian Taiyuan Formation at Seshufen,Mentougou District (Xishan,Beijing)based on a dictyopteran forewing.The new species can be readily separated from other congeners mainly by its prolate clavus. Diverse Phyloblatta dictyopterans have been discovered from the Lower Permian Shanxi Formation in Shanxi Province.The age and biostratigraphy of the insect-yielding formations in Beijing,such as the Tuchengzi,Dahuichang and Xiazhuang formations,are also discussed.Description Tegmen prolate,length 17.3mm,width 6.2 mm.Costal field bandshaped,longer than three-fourths of tegmen length,width 2.0 mm.Sc stem sigmoid, interspace between Sc and R broad,Sc area probably armed with 5-6 branches.Radial field long,triangular,R bifurcated before centre of tegmen,with nine terminal branches.Medial field narrow,M bifurcated distal to the R fork,with three terminal branches.Cubital field narrow, curved distally,CuA with six terminal branches. Clavus tiny,prolate,shorter than half the tegmen length,width 1.3 mm,two veins visible.Discussion The new species can be placed in the extinct Phyloblatta (Phyloblattidae)based on the following combination of characters,bandshaped costal field,with its width equal in the proximal half,and the sigmoid Cul.The new species differs from other congeners in having a tiny clavus,a feature diagnostic for the new species.The anterior half of Phyloblatta beijingensis sp.nov.is similar to that of P.sinica Hong,1980,P.variata Hong,1985 and P. scabrata Hong,1985,but the posterior half is narrow and distinctly different from the latter species.The interspace between Sc and R of P. beijingensis is fusiform,curved,and broad, similar to that of Liroblatta internata Hong,1985 from the bottom of the Permian Shanxi Formation, but the M veins of the latter are well developed, distinct from P.beijingensis.