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| Tarimochara miraclensis Liu, Wu & Riding, A palaeoecological illustrations of T. miraclensis in Late Ordovician marine carbonate platform environments in Liu, Han, Zhang, Tang, Pang, Li, Wu, Hua, Guo, Cai et Riding, 2025. |
Abstract
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.
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| Morphological and palaeoecological reconstructions of Tarimochara miraclensis gen. et sp. nov. a, A morphological reconstruction of T. miraclensis based on fossil specimens and present-day Charophyceae analogues, illustrating the differentiation of nodes and internodes (Inter.) of both main axis and branches, and of whorled branchlets; enlargement of T. miraclensis shows cortical (Cor.) cells of axis, branch, .... The rooting system, orders of branching, number of whorled branches and relative positions of gyrogonites (covered by probable utricle) and antheridium are inferred from the extant corticated genus Chara. b, A palaeoecological illustrations of T. miraclensis in Late Ordovician marine carbonate platform environments. The community composition is based on common associated taxa, for example, green and red algae, corals, bryozoans, and echinoderms. Credit: X. Liu. |
Genus Tarimochara Liu, Wu & Riding gen. nov.
Tarimochara miraclensis Liu, Wu & Riding sp. nov.
Lijing Liu, Jian Han, Zhifei Zhang, Qing Tang, Ke Pang, Ruiyun Li, Yasheng Wu, Hong Hua, Bin Guo, Chunfang Cai and Robert Riding. 2025. Ordovician marine Charophyceae and insights into land plant derivations. Nature Plants. DOI: doi.org/10.1038/s41477-025-02003-y [30 May 2025]
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