The first fossil rust fly (Diptera: Psilidae) from the Insect Bed of the Bembridge Marls of the Isle of Wight is also the first known fossil record of the subfamily Chylizinae. It is late Eocene: Priabonian in age, 34.2 Ma. Chyliza colenutti Ross, Zhou, Hoffeins & Crighton, sp. nov. is compared with 30 extant species of Chyliza and differs from them in having a relatively long 2nd basal cell compared to the discal cell. Some other fossil Acalyptratae records are reviewed and their probable ages updated. The phylogenetic position of the Psilidae is currently uncertain so the family may have appeared anytime from 70–40 million years ago.