Fossil evidence of orchid-like dust seeds in Myanmar amber featuring early angiosperm radiation

Myanmar amber is famous worldwide for its abundant, exquisite, and diverse fossils (including those of flowers). However, the importance and value of this amber flora are still underappreciated. Here we report a group of well-preserved tiny seeds embedded in Myanmar amber. Many winged seeds are concentrated in a very limited space, revealing a high abundance and a great diversity of angiosperms previously unknown. There are another group of seeds probably from a single plant fruit, but they demonstrate variable wingless morphologies. The variable morphologies of these seeds indicate a previously unknown seed morphological plasticity of the mother plant. The common feature of all these seeds is their tiny size. The present discovery reflects that, during their mid-Cretaceous radiation, at least some taxa adopted a strategy similar to that of extant orchids.