We have radiocarbon dated series of tree rings from 2 fossil trees (named ND-113 and the Fuji tree) buried in fossil volcanic avalanche deposits in Japan. They are dendrochronologically floating, dating beyond the tree-ring part of the C-14 calibration curve. The trees show about 350 and 400 annual rings, respectively, which are dated in intervals of 2 to 10 yr. Both sequences are wiggle-matched to the calibration curve IntCal09. This resulted in an age range of 16,534-16,204 cal BP for ND-113, and 23,678-23,290 cal BP for the Fuji tree.