First study on fossil wood from the Middle Pleistocene of the Songliao Plain, Northeast China

Fossil plant, especially fossil wood, is an important tool for detecting climatic changes in the Earth's history. In this study, we report on newly discovered fossil wood from the Middle Pleistocene Huangshan Formation in Changchun City, Jilin Province, Northeast China. To investigate the anatomical characteristics of those permineralized wood, microscopic slides of the transverse, radial, and tangential sections were prepared. The permineralized wood exhibits distinct growth rings, uniseriate or biseriate opposite radial tracheid pits, scarce axial parenchyma, distinctly pitted horizontal and end walls of ray parenchyma cells, 1-16 cells high uniseriate rays, 1-6 subtaxodioid or taxodioid cross-field pits in each unit and traumatic vertical resin canals. The features closely resemble the extant genus Abies. Tree heights were estimated through the application of three classical methods. The distribution and growth pattern of Abies provide important information on the Middle Pleistocene paleoclimate in the Songliao Plain.