Abstract
Kujiberothateruyukii gen. et sp. n., a remarkable new genus and species of Rhachiberothidae, is described from Upper Cretaceous amber from the Kuji area in northeastern Japan. This discovery represents the first record of this family both from Japan and from East Asia. This fossil taxon has the largest foreleg in the subfamily Paraberothinae found to date and its discovery implies that this group had higher morphological diversity in the Cretaceous than it does now. This finding also stresses the importance of the insect inclusions in Kuji amber, which have not been well explored in spite of their potential abundance.