First record of microsporophyll genus Caytonanthus Thomas from Early Cretaceous beds of South Rewa Gondwana Basin, India: Its evolutionary and palaeogeographical significance

详细信息    查看全文

• 作者：Neeru Prakash and Neelam Das
• 刊名：Island Arc
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：26
• 期：1
• 全文大小：1691K
• ISSN：1440-1738

文摘

Pteridosperms (seed ferns) are an extinct group of large and diverse plants. They were dominant elements during Palaeozoic and were also an important component in the Mesozoic vegetation but declined globally in the Cretaceous time with the radiation of angiosperms. The order Caytoniales of Mesozoic pteridosperm is an extinct group of seed ferns in the vegetation. They thrived for about 100 million years from the Late Triassic to the Late Cretaceous. Although they never attained dominant status, their rare occurrence in the vegetation is quite important and fascinating. For this extinct group of seed fern, Thomas (1925) erected a new order Caytoniales which includes three organ genera Caytonia (megasporophyll), Caytonanthus (microsporophyll) and Sagenopteris (leaves). This paper is aimed to document first record of microsporophyll genus Caytonanthus, obtained from the Lower Cretaceous beds of the South Rewa Gondwana Basin of the Indian Peninsula. Its morpho-characters, palaeogeographic distribution, along with its plausible southern origin through ancestral group like Glossopteridales, are surmised here.