A fossil ovule with wind dispersal mechanisms and a probable micropyle.

Anemochory (wind dispersal) represents a key dispersal strategy that has allowed seed plants (spermatophytes) to expand habitats. To facilitate anemochory, the spermatophytes use diverse wind dispersal mechanisms, including wings or plumes of the ovule or seed. Seed wings are integument outgrowths of an ovule, while seed plumes refer to a bundle of filaments. These two wind dispersal mechanisms are independently employed by many seed plants, but are very rarely combined in a single taxon. Seed wings originated in the Late Devonian (Famennian) while seed plumes first appeared in the Early Carboniferous (Mississippian). An opening, or micropyle, in the integument characterizes the ovules of seed plants. This essential structure had not appeared until the Carboniferous, and it evolved through the gradual fusion of integumentary lobes. Famennian ovules demonstrate great diversity in integumentary lobes. Nevertheless, notably few of these earliest ovules exhibit wings or wing-like integumentary lobes and none possess plumes or micropyles. Here, we document a Famennian ovule Gnetopsis quadria sp. nov. from Anhui Province, China. It combines wing-like lobes and plumes as two dispersal mechanisms, and probably has a micropyle.