中国科学院南京地质古生物研究所机构知识库

Molecular phylogenetic analyses indicate that during the Cretaceous Terrestrial Revolution (KTR) around 125-80 Ma, the rapid rise and radiation of angiosperms probably triggered the diversification of mosses and substantial changes of their lineage composition. However, moss fossils which could substantiate these findings are gener-ally rare in the Cretaceous. In this study, we investigate several sterile gametophyte fragments of mosses pre-served in mid-Cretaceous Kachin amber from Myanmar. We describe a new sterile shoot as Vetiplanaxis obtusus sp. nov. (Hypnodendrales), make an emended description of V. pyrrhobryoides Bell based on additional fossil materials, and identify a linear-lanceolate leaf as V. cf. longiacuminatus Hedenas et al. We confirm again the presence of geminate teeth in leaf margin of the above three species studied here, and report the presence of hair-like rhizoids in stem. The phyllotaxis in the species of Vetiplanaxis with complanate shoot is explained as pseudo-tetrastichous, really octostichous, formed by two right-handed Fibonacci spirals. Our findings provide new insights into the circumscription of the Cretaceous moss genus Vetiplanaxis, and add new evidence to indi-cate that there was a diverse pleurocarpous moss flora in the mid-Cretaceous Kachin amber forest of Myanmar. (c) 2022 Elsevier B.V. All rights reserved.