摘要:Nyssopsora eocaenica Tykhonenko and Hayova sp. nov., the only fossil species of the genus Nyssopsora (Pucciniales), is described from the middle Eocene Sakhalinian amber (Russian Far East). It differs from the other known rep-resentatives of the genus by the presence of unbranched hooked appendages on the surface of teliospores. The spores are embedded in the amber sample in close proxim-ity to a syninclusion, Heterotrissocladius naibuchi (Diptera, Chironomidae); most of them are clinged to the insect’s wing or entangled in the bristles on its legs and body. This fossil is ca. 45 myr old and provides useful information for future phylogeny-based calibration and dating of the rust fungi.