A Novel Angiosperm Including Various Parts from the Early Cretaceous Sheds New Light on Flower Evolution

The Yixian Formation (Barremian to Aptian, Lower Cretaceous) of China has yielded many fossils of early angiosperms, but not all of these angiosperms are completely understood. The seeds of angiosperms are attached at different positions in the fruits than those previously reported from the Early Cretaceous, which suggests various provenances for these carpels and indicates the necessity of further investigation of the angiosperms present in the formation to elucidate the diversity and evolution of early angiosperm flowers. Here, we report a novel fossil angiosperm,Varifructus lingyuanensisgen. et sp. nov, which has seeds attached on the dorsal sides of its fruits. The fossils are rendered more intriguing by the fact that there appear to be perianths in the flowers, the fruits are frequently arranged in asymmetrical pairs, and two branching patterns are seen in this single specimen. This unique combination of characteristics provides a rare raw material for evaluating flower evolution in the Early Cretaceous.