FRUITS OF HEMITRAPA (TRAPACEAE) FROM THE MIOCENE OF EASTERN CHINA, THEIR CORRELATION WITH SPOROTRAPOIDITES ERDTMANII POLLEN AND PALEOBIOGEOGRAPHIC IMPLICATIONS

The fruits of the extinct genus Hemitrapa Miki (Trapaceae) are described from the Miocene Shanwang Formation, representing its first fossil record in the Cenozoic of China. Bearing a fusiform, relatively small fruit body with a very long stalk and four sub-equal, strongly ascending, horn-like arms, the Chinese fossil fruits are described as H. shanwangensis Q. Wang new species. Prior to this discovery, a dispersed, trapaceous pollen Sporotrapoidites erdtmanii (Nagy) Nagy was documented from the same formation. Recent paleobotanical and palynological studies in Europe demonstrated that Hemitrapa was closely related to S. erdtmanii, so the co-occurrence of Hemitrapa fruits and S. erdtmanii pollen at Shanwang implies that they may stem from the same parental plant population. Hemitrapa fruits have been widely recognized from the Miocene of mid-latitudes in France, Austria, the Czech Republic, Kazakhstan, Russia, Korea, Japan and the U.S.A. as well as from the late Oligocene-Miocene of Germany and the late Eocene of the Czech Republic. In contrast, dispersed S. erdtmanii pollen has been recovered from the Miocene in central Europe as well as from the late Eocene to the Pliocene of eastern Asiatic shelf basins near the Bohai Sea, Yellow Sea, East China Sea, and the Sea of Japan. Overall, the microfossil and macrofossil records demonstrate that the parental plants of Hemitrapa might have begun to diversify from the mid-latitudes of Eurasia since the Eocene, flourished in eastern Asia and Central Europe during the Miocene, and become extinct after the Pliocene.