Permian carpel-like organs and their implications on origin of angiosperms

Although a widely believed belief assumed that there have been no angiosperms until the Cretaceous, expanding fossil evidence and independent studies are casting increasing doubt over this belief. Ovules/seeds enclosed in a carpel are a trait idiosyncratic of angiosperms, basing on which the famous Archaefructus liaoningensis was recognized as an angiosperm. Many palaeobotanists have long been looking for structures interpretable as carpels in pre-Cretaceous fossils. Here, we report a new fossil, named Permocarpelloides gen. nov. from the Early Permian of Shanxi Province, China. The fossil consists of three structures lying in parallel and containing a number of globular bodies of variable sizes. Based on their morphology, we interpret the fossil as carpels and the bodies inside as ovules/seeds. The occurrence of angiospermy/angio-ovuly in Permocarpelloides suggests that Permocarpelloides is an angiosperm fruit. Compared with previously reported putative Permian angiosperms Taiyuanostachya, Yuzhoua, and Dengfengfructus, Permocarpelloides more closely resembles carpels of modern angiosperms: three orderly arrayed carpel-like structures in a single specimen suggests that they are from a single plant, and that the gynoecium is apocarpous. The discovery of Permocarpelloides adds support to the notion of an ancient, pre-Cretaceous origin of angiosperms.