New ommatids of Ommatinae (Coleoptera: Archostemata: Ommatidae) from the Yixian Formation of western Liaoning, China

Four new fossil species of the family Ommatidae from the Yixian Formation of western Liaoning, China are described. Two of them belong to tribe Brochocoleini: Brochocoleus sulcatus sp. nov. and Brochocoleus angustus sp. nov. The other two refer to tribe Ommatini: Cionocoleus planiusculus sp. nov. and Cionocoleus cervicalis sp. nov. The diagnosis of Brochocoleus and Cionocoleus, respectively, are revised. A preliminary analysis of geographical distribution suggests a possible migration pathway of the genus Brochocoleus. The relationship between the genus Cionocoleus and the extant family Crowsoniellidae is briefly discussed.