Fruits of Firmiana and Craigia (Malvaceae) from the Eocene of the Central Tibetan Plateau with emphasis on biogeographic history
Fruits of Firmiana and Craigia (Malvaceae) from the Eocene of the Central Tibetan Plateau with emphasis on biogeographic history
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DOI：
10.1111/jse.12845
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发表时间：
2022-03
影响因子：
3.7
通讯作者：
C. Del Rio;Teng‐Xiang Wang;Shufeng Li;Lin‐Bo Jia;Pei‐Rong Chen;R. Spicer;Feixiang Wu;Zhekun Zhou-Zhekun
中科院分区：
文献类型：
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作者：
C. Del Rio;Teng‐Xiang Wang;Shufeng Li;Lin‐Bo Jia;Pei‐Rong Chen;R. Spicer;Feixiang Wu;Zhekun Zhou-Zhekun
化石记录证明了北半球锦葵科的古老起源和多样化。青藏高原中部海拔较低，受始新世季风影响，发育了含有锦葵科的亚热带植物区系。对始新世（现在的青藏高原）化石的分类学研究仍在进行中。始新世江郎植物区系的锦葵科化石，归属于樨科和梧桐亚科，并与现代物种进行了比较。一种新的梧桐树标本的描述基于具有羽状脉络的果瓣、从腹缝线开始到达中脉的次脉以及附着在腹缝线近端部分的种子。该标本代表了该属已知最早的出现。还报道了一种新出现的 Craigia，其特征是果实胶囊的膜瓣膜脱落，具有突出的梭形小室区域和辐射状脉络。根据梧桐属的化石记录及其现代分布，我们推测该属可能起源于东亚，随后在华南和东南亚多样化。 Craigia的新出现表明该属在始新世分布于华南、西南和华北的湿润地区。这两份化石记录都证明了西藏地区在东亚和东南亚植物多样化中发挥的重要作用。
The fossil record evidences an old origin and diversification of Malvaceae in the Northern Hemisphere. The central Tibetan Plateau was at a low elevation with a monsoon influence during the Eocene, allowing the development of a subtropical flora containing Malvaceae. The taxonomic study of fossils from the Eocene of what is now the Tibetan Plateau is still ongoing. Malvaceae fossils from the Eocene Jianglang flora, are attributed to sub‐families Tilioideae and Sterculioideae, and are compared with modern species. A new specimen of Firmiana is described based on a fruit valve with a pinnate venation, the secondary veins starting at the ventral suture and reaching the midvein, and the seeds attached at the proximal part of the ventral suture. This specimen represents the earliest known occurrence of the genus. A new occurrence of Craigia is also reported based on detached membranous valves of a fruit capsule with a prominent fusiform locular area and radiating venation. Based on the fossil record of Firmiana and its modern distribution, we infer that the genus may have originated in East Asia and subsequently diversified in South China and Southeast Asia. The new occurrence of Craigia indicates that the genus was distributed in humid areas in South, Southwest and North China during the Eocene. Both fossil records evidence the important role that the Tibetan region played in the diversification of plants in East and Southeast Asia.