Liu Lijing, Han Jian, Zhang Zhifei, Tang Qing, Pang Ke, Li Ruiyun, Wu Yasheng, Hua Hong, Guo Bin, Cai Chunfang, Riding Robert
State Key Laboratory of Continental Evolution and Early Life, Shaanxi Key Laboratory of Early Life and Environment, Department of Geology, Northwest University, Xi'an, China.
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, China.
Nat Plants. 2025 May 30. doi: 10.1038/s41477-025-02003-y.
The emergence of land plants was a pivotal development in Earth history. It has been postulated that the evolutionary transition from freshwater streptophyte algae to land plants, or the canalization of plant meiosis, was completed during the Middle Ordovician (460 Ma). However, the absence of undisputed streptophyte algal fossils (for example, Charophyceae) earlier than the late Silurian (425 Ma) has obscured this link between streptophyte algae and land plants. Here we describe a marine Charophyceae fossil, Tarimochara miraclensis gen. et sp. nov., from early and middle Katian (Late Ordovician, ~453-449 Ma) marine limestones in northwestern China. This discovery demonstrates that at least some species of Charophyceae inhabited shallow normal marine environments at that time. Moreover, these early Charophyceae show that some key morphological innovations associated with an evolutionary transition between streptophyte algae and land plants had occurred before the early Katian. This provides crucial evidence relevant to the origins of land plants.
陆地植物的出现是地球历史上的一个关键发展。据推测，从中奥陶世（约4.6亿年前）开始，从淡水链形植物藻类到陆地植物的进化转变，即植物减数分裂的固定化过程已经完成。然而，早于志留纪晚期（约4.25亿年前）的无可争议的链形植物藻类化石（如轮藻科）的缺失，使得链形植物藻类与陆地植物之间的这种联系变得模糊不清。在此，我们描述了一种来自中国西北部凯迪早期和中期（晚奥陶世，约4.53 - 4.49亿年前）海相石灰岩的海生轮藻科化石——奇迹塔里木轮藻（新属新种）。这一发现表明，当时至少有一些轮藻科物种栖息在浅海正常海洋环境中。此外，这些早期轮藻表明，在凯迪早期之前，与链形植物藻类和陆地植物之间进化转变相关的一些关键形态创新就已经出现。这为陆地植物的起源提供了关键证据。
