Ailanthus americana Cockerell
Oligocene
Ruby River Formation
Ruby River Basin, Madison Co.
Montana, USA.

Beautiful fossil winged fruit of Ailanthus americana Cockerell, an extinct relative of the modern tree of heaven. Preserved in fine-grained sediment, this specimen captures the delicate reproductive structure that allowed the plant’s seeds to be carried by wind across ancient forest landscapes.
35mm winged fruit on 91mm slab. Rare locality.