First flower inclusion and fossil evidence of Cryptocarya (Laurales, Lauraceae) from Miocene amber of Zhangpu (China)

Lauraceae have one of the oldest fossil records of angiosperms with the earliest known evidence from the mid-Cretaceous. However, most of these records are based on leaves, especially from the Cenozoic of Asia, which are often challenging to assign to extinct or extant genera or species. In contrast, fossils of reproductive organs are more informative, but remain scarce. We here describe the first Cenozoic Lauraceae flower of Asia and confirm the presence of Cryptocarya in the Miocene Zhangpu flora (Fujian Province, south-eastern China) based on an amber inclusion. The specimen was scanned using synchrotron radiation-based micro-computed tomography (SRμCT) and compared with extant flowers of the genus. The fossil flower is small, bisexual, and polysymmetric, with a whorled and trimerous perianth and androecium, a hypanthium surrounding the gynoecium, six undifferentiated tepals, nine stamens, three staminodes, and a single superior carpel with a unilocular ovary. The fossil shares an unusual position of staminal glands and a short androecial tube with at least one extant Australian species of Cryptocarya. The discovery of this amber-preserved flower, together with abundant Lauraceae leaf fossils from Zhangpu, supports the interpretation of a megathermal seasonal rainforest environment during the Mid-Miocene.