EQUISETUM CF. PRATENSE (EQUISETACEAE) FROM THE MIOCENE OF YUNNAN IN SOUTHWESTERN CHINA AND ITS PALEOECOLOGICAL IMPLICATIONS.

Rhizomes with tubers of Equisetum cf. pratense Ehrhart are described for the first time from the late Miocene of Lühe, Yunnan Province, southwestern China. The rhizomes consist of distinct nodes and internodes. The nodes bear one to four bunches of tubers (two to four tubers per bunch). The tubers are elliptical, rounded, ovate, or spindle shaped, and the most distal is mucronate. The occurrence of E. cf. pratense would indicate a wet habitat, and the presence of rhizomes with tubers implies that burial occurred during the late fall or winter, assuming that the fossil and its nearest living relative have similar climatic tolerances and phenology. These finds, combined with the presence of thermophilous genera Cyclobalanopsis, Castanopsis, and Liquidambar and hygrophilous elements Alnus and Taxodioxylon, indicate a warm and humid subtropical climate at Lühe in the Miocene. [ABSTRACT FROM AUTHOR]