New insights into the heterosporous lycopsid Changxingia from the Upper Devonian Wutong Formation of Zhejiang Province, China

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• 作者：De-Ming Wang ; Min Qin ; Mei-Cen Meng ; Le Liu…
• 关键词：Changxingia ; Isoёtales sensu lato ; Late Devonian ; Lycopsids ; Monosporangiate strobili ; Wutong Formation
• 刊名：Plant Systematics and Evolution
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：303
• 期：1
• 页码：11-21
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Plant Sciences; Plant Ecology; Plant Anatomy/Development; Plant Systematics/Taxonomy/Biogeography;
• 出版者：Springer Vienna
• ISSN：2199-6881
• 卷排序：303

文摘

A heterosporous lycopsid plant is described from the Upper Devonian (Famennian) Wutong Formation, Changxing County, northern Zhejiang Province, China. The plant is known for its terminal and many detached megasporangiate strobili, most of which do not have sporophylls preserved. Some megasporangiate strobili are closely associated with a vegetative axis bearing leaf cushions and with a mass of microspores. Because of the monosporangiate strobili, the present lycopsid belongs to the Dichostrobiles of the Isoёtales sensu lato. This lycopsid conforms to Changxingia in the vegetative leaves, leaf cushions (including leaf scar and ligule pit), some parts of the megasporophyll (pedicel, heel and lamina), the megasporangium and the megaspores, although the branching pattern of axes, the arrangement and other parts of megasporophyll are still unknown. The fossils are described as Changxingia sp., and this genus is expanded with character of microspore. Hence, the previous and present data indicate that the earliest lycopsids with monosporangiate strobili from the Upper Devonian of China are consistent in Lagenicula megaspores with gula and Lycospora microspores with equatorial cingulum. In contrast, the Carboniferous lycopsids with monosporangiate strobili in Euramerica and Cathaysia show great diversification of both megaspores and microspores.