第九届青年地学论坛

Abstract: A new permineralized gymnospermous fossil wood is described from the Lower Shihhotse Formation (Permian) in Jincheng City, Shanxi Province, North China. The wood is pycnoxylic, possessing tracheids and parenchymatous rays. Growth rings are absent. Radial tracheidal pitting is uniseriate to tetraseriate, and mostly alternately arranged. The percentage of bi-triseriate is 95.2%. Rays are homogeneous, commonly uniseriate, and 1–26 cells high. The cross-field pitting is mainly of the Circopore or glyptostroboid type, rarely pinoid. The number of pits in each cross-field varies from 1 to 11. In most cases, there are 1-3 pits in each field. There is an obvious relationship between the number of cross-field pits and the height of rays. When the rays lower than 3 cells high, there are more than 3 pits in each field. In contrast, when the rays higher than 4 cells, only 1-2 pits are present in each field. The fossil wood of current study is different from those have been described from the Permo-Carboniferous in North China, and may represent a new type based on the anatomy. It is the first fossil plant with anatomical features from the Lower Shihhotse Formation in southeastern Shanxi. Its presence adds our knowledge on the diversity of gymnosperms in the research area during the Permian.

anatomy,fossil wood,lower shihhotse formation,cathaysia flora