A typical Euramerican floral element from the Shanxi Formation (Cisuralian, lower Permian) in the Wuda Coal Field, Inner Mongolia, North China

摘要

Autunia conferta (Sternberg) Kerp is one of the best known, earliest and most widespread callipterids in Euramerica during the Cisuralian. Unambiguous A. conferta foliage is for the first time recorded from Cathaysia in the Shanxi Formation of Wuda, Inner Mongolia, North China. Together with the find of Autunia naumannii (Gutbier) Kerp in the lowermost Permian strata of the same region, it proves that the radiation and spatio-temporal distribution of peltasperms was apparently not hampered by the floral provincialism, and it also indicates a mutual migration of floral elements between Cathaysia and Euramerica. Their long stratigraphic range, from the Cisuralian to the Lopingian, demonstrates that callipterids played an important role in the palaeotropical landscape and had a long history in North China during the Permian. The nearly absence of callipterids in typical Cisuralian wetland floras indicates their preference for well-drained settings and uplands. It is inferred that A. conferta lived contemporaneously with the wetland floral elements in Cathaysia during the Cisuralian, but commonly outside the window of preservation.