Fullerenes have been identified by high-performance liquid chromatography with UV-visible spectroscopic analysis of toluene extracts of deep sea claystones from Permo-Triassic (P/T) boundary sections in the Inuyama area, central Japan. The analysis reveals the presence of 10--20 parts per trillion of C60 only in the dark-colored rock samples, suggesting the anoxia at the time of the P/T boundary 250 million years ago, when the greatest Phanerozoic mass extinction occurred. The fullerenes were likely synthesized within locally anoxic zone in the extensive wildfires on the supercontinent Pangea and deposited on an anoxic deep-sea floor of the superocean Panthalassa. ¿ 1999 American Geophysical Union