Premise of research. Climbing plants are important components of modern-day tropical forests and primarily comprise angiosperms, but in Paleozoic tropical forests, pteridosperms were the dominant climbers. Climbing pteridosperms are well known from the Paleozoic floras of Euramerica, while much less is known about climbing pteridosperms from other phytogeographic regions. We document from the earliest Permian Taiyuan Formation of Cathaysia a new genus and species of a small vine preserved in situ and in 3D in a volcanic tuff bed from the Wuda locality. We consider the affinity and ecology of the new plant and evaluate its abundance and distribution in the Wuda forest community. Methodology. Macrofossils were prepared by dégagement, and sharpened needles were used to expose the plant from the overlying sediment. Anatomy was revealed by petrological thin sections. Key features of the plant were observed under scanning electron microscopy. Pivotal results. Only the aerial organs of the plant are known, and they comprise stems up to 4.5 mm in diameter that bear hooked prickles and fronds. Branching is irregular, probably axillary, with buds situated in axils of the stem and fronds. Stems are eustelic with well-developed secondary xylem. Lanceolate and distinctly asymmetric bipinnate fronds arise from the stem in nodes. Fronds show considerable variation in both size and shape, and pinnules are strongly heterophyllous. Large pinnules have relatively long conical pinnule lobes terminated by pads that are adapted for climbing, which we consider to be pinnule climbing adaptations. Epidermal cells on pinnules have large paracytic stomatal apparatuses. Fertile pinnules with well-developed pinnule laminae appear to have borne reproductive organs above lateral veins and between the midvein and the pinnule margin on the lower (abaxial) pinnule surface. Fertile structures are incompletely preserved and appear to represent pollen organs; seeds are unknown. Conclusions. Although its fertile organs are unknown, characters of the new plant are most similar to those of the pteridosperm family Callistophytales and in particular Callistophyton, but it is distinct from existing genera, leading to the erection of Wudaeophyton wangii gen. et sp. nov. Wudaeophyton wangii is reconstructed as a vine climbing on Psaronius marattialean fern associations in the bottom of the tuff bed and on Cordaites gymnosperm associations at the top. We interpret W. wangii to most likely be a member of the Callistophytales, leading us to consider the persistence and evolutionary diversification of Callistophytales in the Cathaysian floras after their regional extirpation in Euramerica, which broadly coincided with the onset of the Permian, and their eventual extinction in the Lopingian (upper Permian) before the end-Permian mass extinction event.

中文翻译：

---

华北最早二叠纪森林中一株攀附于 Psaronius 和 Cordaites 树上的小异叶藤本植物

研究的前提。攀援植物是现代热带森林的重要组成部分，主要包括被子植物，但在古生代热带森林中，蕨类植物是主要的攀援植物。攀缘蕨类植物在欧美洲的古生代植物群中广为人知，而对来自其他植物地理区域的攀缘蕨类植物知之甚少。我们从最早的 Cathaysia 二叠纪太原组记录了在乌达地区的火山凝灰岩床中原位和 3D 保存的小藤本植物的新属和种。我们考虑了新植物的亲和力和生态，并评估了它在乌达森林群落中的丰度和分布。方法。大型化石是通过 dégagement 制备的，并使用锋利的针头将植物从上覆的沉积物中暴露出来。通过岩石薄切片揭示了解剖结构。在扫描电子显微镜下观察到植物的主要特征。关键结果。只有植物的气生器官是已知的，它们包括直径达 4.5 毫米的茎，带有钩状的刺和叶。分枝不规则，可能是腋生，芽位于茎和叶的腋下。茎是eustelic，具有发达的次生木质部。披针形和明显不对称的二回羽状叶从节中的茎产生。叶状体在大小和形状上都表现出相当大的变化，羽叶具有强烈的异叶性。大的羽片具有相对较长的圆锥形羽片裂片，末端由适合攀爬的垫子终止，我们认为这是羽片攀爬适应性。小叶上的表皮细胞具有大的副细胞气孔器。具有发育良好的羽片叶的可育羽片似乎在侧脉上方和中脉和羽片下部（背面）表面的羽片边缘之间具有生殖器官。可育结构未完全保存，似乎代表花粉器官；种子未知。结论。虽然其受精器官未知，但新植物的性状与蕨类植物Callistophytales，特别是Callistophyton最为相似，但与现有属不同，导致了Wudaeophyton wangii gen的建立。等 sp. 十一月 Wudaeophyton wangii 被重建为攀爬在凝灰岩床底部的 Psaronius marattialean 蕨类植物群和顶部的 Cordaites 裸子植物群落上的藤蔓。我们将 W. wangii 解释为最有可能是 Callistophytales 的成员，