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Cone‐producing gymnosperms are important elements of the Mesozoic floras. Studying their cone organizations can potentially help us understand the evolutionary trends of seed plants through time and the origin of angiosperms. In this paper, we present a new and an undetermined species of Ixostrobus Raciborski, a fossil genus representing male cones of the Czekanowskiales from the Middle Jurassic Daohugou locality in Inner Mongolia, China. The holotype specimen of the new species was studied using the neutron tomography (NT) technique. The cone shows higher neutron attenuation than the surrounding matrix. To detect the different organic compounds, a volume rendering of tomographic reconstruction with false colour spectrum of relative neutron attenuation is presented. The highest concentration of organic material is in the axis and some parts of the sacs, the rest of the cone has lower concentration, and the surrounding matrix has the lowest concentration. It seems that the remnant organic materials are regularly differentiated in different parts of the cone probably because of the preservation and different taphonomic process of different type of cells. In addition to revealing more detailed morphological features of the cone by NT reconstruction, the application of NT is potentially important for detecting remnant organic materials preserved in fossil plants. [ABSTRACT FROM AUTHOR]

The Yuzhou Flora of the southern North China Platform possesses the typical regional features of the Middle and Late Cathaysian Flora. For a long time during the Permian, this area was located on shoreline marine tidal flats and deltas at low latitudes with a warm and humid climate. Consequently, many successive layers with abundant well-preserved plant fossils and a complete evolutionary sequence were developed. This is a unique and ideal place to study the Middle and Late Cathaysian Flora. We have recognized 111 genera and 307 species from this flora. The rapid morphological evolution and uninterrupted stratigraphic succession of Lobatannularia (Sphenophytes) make this group one of the bases for biostratigraphic divisions of the Permian System of the North China Platform. Ninety percent of Pteridophytes belong to the order Marattiales, which are well developed during the early and middle stages of the Yuzhou Flora but experience a sudden decline during the late stage. Ancient Pteridospermatophytes only flourished during the Middle Permian whereas advanced Peltaspermales are extremely well developed at the end of the early Late Permian. Among them Shenzhouphyllum is one of characteristic elements in the late stage of the Yuzhou Flora. The Cycadophytes evolved relatively early in this area and they differentiated and proliferated during the late Middle to early Late Permian. The number of species of Ginkgophytes is small but this group is extremely abundant, especially in the early Late Permian. The Gigantopteridales (preangiosperms) is a very important and unique group in the Yuzhou Flora. Based upon their venation and leaf architecture, this group can be divided into three evolutionary stages, i.e., appearance and differentiation, first flourishing, and second flourishing and sudden disappearance, which form the basis for biostratigraphic division and correlation of the Permian System of the North China Platform. Based upon the evolutionary trend of venation pattern and leaf architecture, we propose some taxonomic changes at the generic level. The Yuzhou Flora emerged at the middle Early Permian (Zisongian) and suddenly disappeared at the early Late Permian (Wujiapingian). It is later replaced by the Euro-American Zechstein flora in the late Late Permian. The Yuzhou Flora is divided into three (early, middle and late) stages based upon the cyclic development of its plant groups. Five fossil plant assemblage zones are recognized from the Yuzhou Flora based upon the succession of each group and their combined characters in different layers. [ABSTRACT FROM AUTHOR]

The Middle Jurassic Daohugou Biota is named for a fossil assemblage after a village in Ningcheng County, Inner Mongolia, China. Over the last twenty-five years, abundant, exceptionally well-preserved fossils have been reported from various localities in the Daohugou area. While the fauna of the Daohugou Biota has been well-studied, little research has been done on the flora. In this paper, we establish the Daohugou Flora for the first time and document its high diversity of plants which are mainly composed of Filicopsida, Cycadopsida, Ginkgopsida, Czekanowskiales and Coniferopsida. We recognize 49 species belonging to 32 genera, including a new species Sphenobaiera eximia sp. nov. Na, Sun et Wang. An emended diagnosis of Anomozamites villosus Pott, McLoughlin, Wu et Friis is presented. The floristic composition indicates that the Daohugou Flora belongs to the North Floristic Province and it reflects a warm-temperate and humid climate with seasonal temperature and precipitation variations. This report, representing the first systematic treatment of fossil plants from the Daohugou area, is of great significance for understanding the Daohugou Biota. It also provides important information for reconstructing the paleoclimate and paleoenvironment in this area, and lays a solid foundation for studying co-evolution of plants and animals of the Daohugou Biota. [ABSTRACT FROM AUTHOR]