A new planthopper genus Tenebricosus gen. nov. from mid-Cretaceous Kachin amber with its type species Tenebricosus coriaceus sp. nov. is described in the family Mimarachnidae. The new genus and species is the fourteenth genus and 22nd species of the extinct family Mimarachnidae, which is the most diverse planthopper family among Kachin amber inclusion. This genus can be distinguished from the preciously described genera in tegmen venation, with stem ScP + R shorter than the common stem ScP + R + MP, stem MP with two terminals in margin, costal cell broad and tegmen coriaceous with length/width ratio about 2.4. Diagnostic features of the new genus are briefly discussed.

一种新的飞虱属Tenebricosus gen。十一月 来自白垩纪中期克钦琥珀及其类型物种Tenebricosus coriaceus sp。十一月 在家庭 Mimarachnidae 中有所描述。新属新种是已灭绝的蚱蜢科第14属第22种，是克钦琥珀包裹体中种类最多的飞虱科。该属可与盖脉中的珍贵描述属区分开来，茎 ScP+R 比普通茎 ScP+R+MP 短，茎 MP 边缘有两个末端，肋细胞宽，被盖革质，长宽比约为2.4. 简要讨论了新属的诊断特征。