A nepticulid leaf-mine ichnofossil is described on the basis of a fossil leaf of Fagus from the early Miocene Geumgwangdong Formation (ca. 21–14 million years ago) in Pohang basin. This mine trace is characterized by a linear-blotch type with clear centric frass trail of closely and randomly dispersed pellets filling the mine width in early stage. We found traces of possible egg case and exit slit from the fossil. These features are most consistent with those produced by Nepticulidae. Our record represents the only reliably-identified nepticulid leaf-mine on Fagus in Miocene. Nepticulid leaf-mines in Miocene and the leaf-mine fossils from the Geumgwangdong Formation are briefly reviewed.

• Jae-Cheon Sohn(Institute of Littoral Environment, Mokpo National University, Muan, Republic of Korea)
• Camiel Doorenweerd(Department of Plant and Environmental Protection Sciences, University of Hawaii, Honolulu, USA)
• Kye Soo Nam(Daejeon Science High School for the Gifted, Daejeon, Republic of Korea)
• Sei-Woong Choi(Department of Environmental Education, Mokpo National University, Muan, Republic of Korea)