A new genus and species of Microphysidae (Hemiptera: Heteroptera) with long labium in Late Cretaceous Iwaki amber from Futaba Group of Iwaki City, Fukushima Prefecture, Japan

The Iwaki insect-bearing amber from Fukushima Prefecture, northeastern Honshu, Japan, is considered from the Late Cretaceous Coniacian age. The insect-bearing amber localities from that period are few worldwide. Here, we report Iwakia longilabiata gen. et sp. nov., a new fossil genus and species of the infraorder Cimicomorpha Leston, Pendergrast and Southwood, 1954 (Hemiptera: Heteroptera) from the Futaba Group of Iwaki City. Although the preservation is incomplete, this fossil is provisionally placed in the family Microphysidae Dohrn, 1859 based on the general consistency of the diagnostic characters of the family. The fossil is distinguishable from any genus of Cimicomorpha including Microphysidae because of its long labium and brachypterous female. Additionally, the fossil shares the female diagnostic characteristics of the Palaearctic and Nearctic taxa, suggesting that it is an early stage in the evolution of sexual dimorphism of the family Microphysidae. The evolution of sexual dimorphism in Microphysidae may have already occurred in East Asia during the Late Cretaceous Coniacian age. This fossil may be the first discovery from Asia and the oldest record of the family Microphysidae.