Hydrasperman pteridosperm ovules from the Permian of China: palaeoecological and palaeobiogeographic implications
Hydrasperman pteridosperm ovules from the Permian of China: palaeoecological and palaeobiogeographic implications
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DOI：
10.1080/08912963.2020.1867125
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发表时间：
2021-01
影响因子：
1.4
通讯作者：
Xiaoyuan He;Alan R. T. Spencer;Shijun Wang;J. Hilton
中科院分区：
文献类型：
--
作者：
Xiaoyuan He;Alan R. T. Spencer;Shijun Wang;J. Hilton
摘要水龙(Hydrasperman)蕨类(种子蕨类)广泛分布于欧亚大陆石炭纪赤道湿地，虽然存在于华夏二叠纪赤道湿地，但对它们的胚珠(未受精种子)却知之甚少。Hydrasperman胚珠可以从其独特的花粉室组织中辨认出来，但那些以前从华夏二叠纪植物群中发现的胚珠的特征并不完美，需要进一步研究以确认它们的亲和力和身份。在这里，我们记录了Hyasperman胚珠孔菌cf。中国北部太原组早二叠世煤球中的裸子植物，其初步发现已发表在一本关于中国煤球植物群的中文书中。我们提供了有关胚珠组织和结构的更多信息，并首次考虑了它们的古生态和古地理意义。我们得出的结论是，在宾夕法尼亚晚期，湿地植物物种在欧亚大陆和华夏之间的迁移过程中发生了显著的分类过滤，由于栖息地丧失和气候变化，大部分欧亚混血蕨类在石炭纪末期灭绝。保留在华夏植物区系中的为数不多的海蛇属和物种是二叠纪赤道湿地植物群的遗迹和次要组成部分。
ABSTRACT Hydrasperman pteridosperms (seed ferns) were widespread and diverse in Carboniferous equatorial wetlands of Euramerica, and although present in Permian equatorial wetlands in Cathaysia, little is known about their ovules (unfertilised seeds) from this phytogeographical realm. Hydrasperman ovules are recognisable from their distinctive pollen chamber organisation, but those previously noted from the Permian floras of Cathaysia are imperfectly characterised and require further study to confirm their affinity and identity. Here we document the hydrasperman ovule Conostoma cf. kestospermum from coal-balls in the early Permian aged Taiyuan Formation of North China for which preliminary findings were previously published in a Chinese language book on the coal-ball floras of China. We provide additional information on the organisation and structure of the ovules and for the first time consider their palaeoecological and palaeogeographical significance. We conclude that significant taxonomic filtering occurred in the migration of wetland plant species between Euramerica and Cathaysia in the late Pennsylvanian, with the majority of hydrasperman pteridosperms going extinct in Euramerica at the end of the Carboniferous as a result of habitat loss and climate change. The few hydrasperman genera and species that persisted into the Cathaysian flora were relicts and a minor component of Permian equatorial wetland floras.