The isolated and anatomically_preserved lepidodendralean leaf cushions were described from coal balls in Wangjiazhai Formation (upper Upper Permian) in western Guizhou Province. These leaf cushions are very similar t...The isolated and anatomically_preserved lepidodendralean leaf cushions were described from coal balls in Wangjiazhai Formation (upper Upper Permian) in western Guizhou Province. These leaf cushions are very similar to Lepidodendron lepidophloides Yao both in size and morphology. They probably belong to the same species in different preservative condition. Comparisons on morphology and anatomy of L. lepidophloides and lepidodendralean leaf cushion genera, such as Lepidodendron, Lepidophloios, Sigillaria and Cathaysiodendron revealed that L. lepidophloides possesses mixed features of all these genera and it can not be assigned into any of them without doubt. It probably represents a new genus. Because the anatomical features of the other parts of the stem as well as the fertile organs related to these leaf cushions are unknown, the specific name L. lepidophloides is adopted. We leave this taxonomic problem open till the relationship between these leaf cushions and the stem and fertile organs become clear. This is the first report on the detailed anatomical features of the Cathaysian lepidodendralean leaf cushions.展开更多
A new Bergeria(Lepidodendrales, Flemingitaceae), B. wenquanensis sp. nov., is described in this paper, typically characterized by the longest and elongated leaf cushions ever found. The specimen, collected from the Mi...A new Bergeria(Lepidodendrales, Flemingitaceae), B. wenquanensis sp. nov., is described in this paper, typically characterized by the longest and elongated leaf cushions ever found. The specimen, collected from the Mississippian of Wenquan County, Xinjiang Uygur Autonomous Region, China, is represented by a fossil stem about two meters long, with distinct leaf cushions. The genus Bergeria has usually been assigned to partially decorticated Lepidodendron stems. Although Cathaysian Lepidodendron have been extensively reported in China, most of them were found in the central, eastern and southern parts of the country, rarely in northwestern China. This new species is so far the westernmost record and the most isolated representative from the Cathaysian Lepidodendron center.Based on the distribution of the Cathaysian Lepidodendron during the Mississippian, most of the species were in the South China Plate near the Equator, while the new species is discrete in the north, far from the Equator. According to the spatiotemporal distribution of Cathaysian Lepidodendron, this genus appeared during the Mississippian, a period which was represented by rather few species, it flourished and expanded northwards during the Pennsylvanian, taking the north block of the South China Plate as the center. Since the Cisuralian to the Guadalupian, the genus became gradually sparser in all areas of distribution, probably due to strong climate change. During the Lopingian, the genus migrated southwards to the South China block and had a broader distribution range again, and it became extinct to the end of this interval. The new species is also significant for the evolution of Lepidodendron leaf cushions. During the Mississippian, the primitive species of Lepidodendron usually had narrow, fusiform leaf cushions, while the Pennsylvanian or Permian species were more variable in shape of leaf cushions, from inverted water-drop, rhomboidal, hexagonal, trapeziform to horizontal rhomboidal.展开更多
文摘The isolated and anatomically_preserved lepidodendralean leaf cushions were described from coal balls in Wangjiazhai Formation (upper Upper Permian) in western Guizhou Province. These leaf cushions are very similar to Lepidodendron lepidophloides Yao both in size and morphology. They probably belong to the same species in different preservative condition. Comparisons on morphology and anatomy of L. lepidophloides and lepidodendralean leaf cushion genera, such as Lepidodendron, Lepidophloios, Sigillaria and Cathaysiodendron revealed that L. lepidophloides possesses mixed features of all these genera and it can not be assigned into any of them without doubt. It probably represents a new genus. Because the anatomical features of the other parts of the stem as well as the fertile organs related to these leaf cushions are unknown, the specific name L. lepidophloides is adopted. We leave this taxonomic problem open till the relationship between these leaf cushions and the stem and fertile organs become clear. This is the first report on the detailed anatomical features of the Cathaysian lepidodendralean leaf cushions.
基金supported by the National Natural Science Foundation of China under the Grant 41271070the West Light Foundation of Chinese Academy of Sciences under Grant 2015-XBQN-B-25
文摘A new Bergeria(Lepidodendrales, Flemingitaceae), B. wenquanensis sp. nov., is described in this paper, typically characterized by the longest and elongated leaf cushions ever found. The specimen, collected from the Mississippian of Wenquan County, Xinjiang Uygur Autonomous Region, China, is represented by a fossil stem about two meters long, with distinct leaf cushions. The genus Bergeria has usually been assigned to partially decorticated Lepidodendron stems. Although Cathaysian Lepidodendron have been extensively reported in China, most of them were found in the central, eastern and southern parts of the country, rarely in northwestern China. This new species is so far the westernmost record and the most isolated representative from the Cathaysian Lepidodendron center.Based on the distribution of the Cathaysian Lepidodendron during the Mississippian, most of the species were in the South China Plate near the Equator, while the new species is discrete in the north, far from the Equator. According to the spatiotemporal distribution of Cathaysian Lepidodendron, this genus appeared during the Mississippian, a period which was represented by rather few species, it flourished and expanded northwards during the Pennsylvanian, taking the north block of the South China Plate as the center. Since the Cisuralian to the Guadalupian, the genus became gradually sparser in all areas of distribution, probably due to strong climate change. During the Lopingian, the genus migrated southwards to the South China block and had a broader distribution range again, and it became extinct to the end of this interval. The new species is also significant for the evolution of Lepidodendron leaf cushions. During the Mississippian, the primitive species of Lepidodendron usually had narrow, fusiform leaf cushions, while the Pennsylvanian or Permian species were more variable in shape of leaf cushions, from inverted water-drop, rhomboidal, hexagonal, trapeziform to horizontal rhomboidal.
